CAtlFORNIA o c iV ( R 3 13 10 junrnn SH; O Of CALIFORNIA SANTA BARBARA THE DESIGN AND CONSTRUCTION OF OIL ENGINES WITH FULL DIRECTIONS FOR ERECTING, TESTING, INSTALLING RUNNING AND REPAIRING INCLUDING DESCRIPTIONS OF AMERICAN AND ENGLISH KEROSENE OIL ENGINES WITH AN APPENDIX ON Marine Oil Engines BY A. H. GOLDINGHAM Member of the Institution of Mechanical Engineers, London: Member of the American Society of Mechanical Engineers; Member of the Society for the Promotion of Engineering Education. FOURTH EDITION, ENLARGED NEW YORK: SPON & CHAMBERLAIN, 123-125 Liberty Street LONDON: E. & F. N. SPON, LIMITED, 57 Haymarket, S.W. 1914 THE DESIGN AND CONSTRUCTION OF OIL ENGINES WITH FULL DIRECTIONS FOR ERECTING, TESTING, INSTALLING RUNNING AND REPAIRING INCLUDING DESCRIPTIONS or AMERICAN AND ENGLISH KEROSENE OIL ENGINES WITH AN APPENDIX ON Marine Oil Engines BY A. H. GOLDINGHAM Member of the Institution of Mechanical Engineers, London: Member of ERRATA The numbers to Figs. 50 and 51 should read 51 and 50. SPON & CHAMBERLAIN, ius-125 liberty sweet LONDON: E. & F. N. SPON, LIMITED, 57 Hayraarket, S.W. 19U Copyright, 1900. Copyright, 1904. Copyright, 1910. Copyright, 1914. By Arthur Hugh Goldingham. PREFACE TO FOURTH EDITION SINCE the publication of the third edition of this book the remarkable and rapid development of large marine oil engines for the propulsion of ocean going and other steamers has taken place. In order to bring this book thoroughly up-to-date, the preparation of matter relative to such engines has been necessary. This is now presented in the appendix at the end of the book. The writer is indebted to the various publishers hereafter named for their courtesy in placing illustra- tions at his disposal for reproduction and for allowing him to make extracts from their descriptive matter. He also wishes to thank various manufacturers who have placed at his disposal data relative to their re- spective engines. The illustrations, etc., of the Diesel engine in the ship "France" are inserted by permission and courtesy of Engineering, London, and by permission of the builders of that engine. The illustrations of various sprayers or pulverizers and descriptive matter regarding them are given by permission of the publishers of Cassiers Magazine, London. iv PREFACE TO FOURTH EDITION Extracts and illustrations of the Sulzer and M. A. N. engines are from the address given before the Am. Soc. of Mech. Engineers by the late Dr. Rudolf Diesel by permission of that Society. Illustrations and descriptive matter of the Carel Freres engine have been furnished by Mr. Haynie, their United States representative. The New London Ship & Engine Co., Busch Sulzer Bros. Diesel Co., the Snow Pump Co. and the De La Vergne Machine Company have each furnished in- formation regarding their respective engines. The assistance and courtesy extended by the above and others who have assisted in the preparation of this matter is hereby acknowledged. PREFACE TO THIRD EDITION THE previous editions being exhausted the third edition of this work has been prepared to meet the increasing demand for a reliable handbook on Oil Engines. Necessary revisions in the third edition have been made in an endeavor to completely cover the subject both with regard to Modern Oil Engines as well as to those previously made. In Chapter I the text of some pages has been changed with the addition of descriptive matter and illustrations of Recent Oil Spraying and Vaporizing Devices. In Chapter II on Design and Construction considerable revision has been rendered necessary to conform to up-to-date practice. Additions have been made to Chapter III on Testing. Numerous formulae have been added, "others have been changed while each has been carefully checked and compared with the design of the best and most successful engines built. Other additions have been made -to Chapters IV, V, and VI, as well as to Chapters X, XII and XIII. Many new illustrations have been prepared with the greatest care regardless of cost. The writer wishes to acknowledge his obligation to all who have assisted him in the work of revision and to thank the different manufacturers for the in- formation, photographs, diagrams, etc., placed at his disposal by them. A. H. G. NEW YORK, December, 1909. PREFACE TO SECOND EDITION THE first edition having been exhausted, and in order to meet the continued and increasing demand for this work, a new and larger edition is now presented. It has been the endeavor of the writer to embody in the present edition the most recent information on the subject. Chapters on "Oil Engine Troubles," "Fuels" with numerous tables, and "Miscellaneous," including fire insurance rules, have been added, while large-sized oil engines and portable engines have received a more extended description. Reference to all types of engines has been made about which information could be secured. The writer is indebted to Professor William Robin- son for permission to reproduce tables from "Gas and Petroleum Engines ;" also to Messrs. Clifford Richard- son and E. C. Wallace for the matter given regarding Texas crude oil ; to the "Scientific American" for Fig. 920. PREFACE THIS work has been written with the intention of supplying practical information regarding the kero- sene or oil engine, and in response to frequent re- quests received by the writer to recommend such a book. Whilst many works have been published on the subject of gas engines, some of which refer to or describe the working of .the oil engine, no other book, it is believed, is devoted entirely to the oil engine in detail. The work, it is hoped, will be found useful to the draughtsman, the engine attendant, as well as to those who own or are about to install Oil Engines. The classification of vaporizers has been adhered to as made some few years ago, and a representative engine with each type is described. The matter on design and construction is founded on practical experience, the formulae, it is believed, being in accordance with the best modern practice. Chapter III. on Testing is based on the writer's personal experience in the testing-room. viii PREFACE. The writer is particularly indebted to Mr. George Richmond for many valuable suggestions, and also for reading the proof-sheets, and he wishes to acknowledge assistance from many firms, amongst which may be mentioned Ingersoll Sargeant Drill Company for Table III., Mr. Frank Richards for Table II., The De La Vergne Company for Table IV., London Engineer, Tables V. and VI. Table I. is partly taken from Mr. William Norris's book on the Gas Engine, and Tables VII., VIII., IX., and X., at the end of the book, relating to different oils, are taken (with per- mission) from Mr. Boverton Redwood's valuable work on Petroleum. And to the Engineering News for permission to use Figs. 44^ and 44^. The Crosby Steam Gauge Company have also supplied informa- tion relating to the indicator and planimeter. A. H. GOLDINGHAM. NEW YORK, November i, 1900. CONTENTS. CHAPTER I. INTRODUCTORY. PAGE Historical Classification of Oil Engines Various Vaporizers Different Igniting and Spraying De- vices The Different Cycles of Valve Movements 1-19 CHAPTER II. ON DESIGNING OIL ENGINES. Simplicity in Construction and Arrangement of Parts Comparison of Oil and Gas Engines Cyl- inders, Different Types Cylinder Clearance Crank-shaft, Dimensions and Formulae Balanc- ing of Crank-shafts Described Connecting-rods, Strengths, etc. Piston, Piston-rings Piston speed Fly-wheels, Formula for Air and Ex- haust Cams Cylinder Lubricators Valves and Valve-boxes Velocity of Air through Valves Crank-shaft Bearings Proportions of Engine Frame Crank-pin Dimensions Valve Mechan- isms, Gearing and Levers Governing Devices Exhaust Bends Oil-supply Pump Oil-tank and Filter Comparison of Horizontal and Vertical Type Engines, with Advantages of Each Two- cylinder Engines Discussed Assembling of Oil- enginesScraping in Bearings Fitting of Piston and Piston-rings Fitting Connecting-rod Bear- ings Fitting Air and Exhaust Valves Test- ing Water-jackets Fly-wheel Keys Oil-supply Pipes Cylinder Made in Two or More Parts, .. 20-58 ix X CONTENTS. CHAPTER III. TESTING ENGINES. PAGE Object of Testing Comparison with Steam-engines Different Records to be Taken Diagram for set- ting Valves Preparing for Test Heating of Va- po'rizer Starting Difficulties of Starting Com- pression, How to Test Leakage of Valves and Cylinder Lubrication of Piston and Bearings Easing Piston Synonymous Terms for Power De- veloped Indicated Horse-power Brake, Horse- power Indicator Fully Described Reducing Motions Planimeters Indicator-cards described in Detail and Analyzed Defects as Shown by Indicator How to Remedy Same Early and Late Ignition, How to Alter The Compression and Expansion Lines Choked Exhaust Mean Effective Pressure, How to Increase Back Pres- sure of Exhaust Tachometers Fuel-consump- tion Test Fully Described Mechanical Efficiency Thermal Efficiency Table of Disposition of Heat Valve Diagram Exhaust Gases Complete and Incomplete Combustion Testing the Flash- point of Kerosene Viscosometer, 59-95 CHAPTER IV. COOLING WATER-TANKS AND OTHER DETAILS. Water Connections Capacity of Tanks Required Gravitation System of Circulation Water-pumps Connection to City Water Main Temperature of Outlet Water Emptying Pipes in Frosty Weather Salt Water Exhaust Silencers Brick Pit, How to Construct Exhaust-Gas Deodorizer, CONTENTS. XI PAGE How to Connect Connecting Circulating Water to Exhaust-pipe Self-starters, Why Necessary Utilizing Waste Heat of Exhaust Gases and of Cooling Water, Different Methods Exhaust Temperature, .. .. .. .. .. .. 96-110 CHAPTER V. OIL ENGINES DRIVING DYNAMOS. Isolated Plants Advantages of Oil Engines as Com- pared with Gas and Steam Engines Installation of Plant Foundation, How to Build, Ingredients Correct Location of Engine and Dynamo Belts Balance-wheel on Armature Shaft Power Required for Incandescent and Arc Lamps Losses of Power by Belt and Otherwise Regu- lation of Engine Required for Electric Lighting Direct-connected Plants, Advantages of Same Variations in Incandescent Lights, Causes, How to Remedy Silencing Air-suction, .. .. .. 111-122 CHAPTER VI. OIL ENGINES CONNECTED TO AIR-COMPRESSORS, WATER-PUMPS, ETC. Direct-connected and Geared Air-compressing Outfits, with Dimensions and Pressures Obtained Calcu- lations of Horse-power Required Tables of Pres- sures and Other Data Efficiencies at Different Altitudes Pumping Outfits Described in Detail, with Dimensions How to Calculate Horse-power Required Oil Engines Driving Ice and Refrig- erating Machines, Calculations of Power Required Friction-clutches, .. .. .. .. .. 123-138 xii CONTENTS. CHAPTER VII. INSTRUCTIONS FOR RUNNING OIL ENGINES. PAGE General Instructions and Remarks Cylinder Lubri- cating Oil Instructions in Detail as to Running Hornsby-Akroyd Type, the Crossley Type, the Campbell Type, and the Priestman Type of Oil Engine General Remarks Regulation of Speed How to Reverse Direction of Running of En- gine, with Diagrams of Valve Settings, .. .. 139-156 CHAPTER VIII. REPAIRS. Drawing Piston Taking Off Piston-ring Grinding in of Valves Adjustment of Crank-shaft and Connecting-rod Bearings How to Fit New Piston-ring to Cylinder Fitting New Skew and Spur Gear Renewing Governor Parts, .. .. 157-160 CHAPTER IX. OIL ENGINE TROUBLES. Ignition Electrical Connections Tube Igniter Automatic Igniter Oil Supply Air Supply Knocking Loss of Power Piston Blowing- Explosions in Silencer Water Leakage, . . . . 161-167 CONTENTS.- XH1 CHAPTER X. VARIOUS ENGINES DESCRIBED. PAGE General Description, with Illustrations of Different American and English Oil Engines Method of Working Sectional Cuts The Crossley The Cundall The Campbell The Priestman The Mietz & Weiss The Hornsby-Akroyd The Diesel The Rites Governor Britannia Co.'s Engine International Power Co. The Barker, 168-199 CHAPTER XI. PORTABLE ENGINES. General Description of Portable Oil Engines Por- table Electric Lighting Water Cooling Appa- ratus Crossley Mietz & Weiss Portable Air Compressor Hornsby-Akroyd Traction Engine, 200-205 CHAPTER XII. LARGE SIZED ENGINES. Comparison of Cycles Relative Cost of Installation and Operation of Steam, Gas, and Oil Engines Mietz & Weiss Diesel Hornsby-Akroyd Sectional Views Tests Use of Crude Oil- Moore & Co. Vaporizer or Producer Fair- banks Morse Engine, 206-229 CHAPTER XIII. FUELS. Description of Various Fuels Beaumont Crude Oil Russian and American Crude Oil Analyses Various Tables California Crude-Fuel Oil, . . 230-240 x i v CONTENTS. CHAPTER XIV. MISCELLANEOUS. PAGE Comparison of U. S. and American Measures and Weights-Various Tables-Fire Insurance- Tests of Various Engines, 241-251 TABLES PAGE I. Sizes of Crank-shafts, 27 II. Various Air Pressures, 126-127 III. Efficiencies of Air Compressors at Differ- ent Altitudes, 129 IV. Mean Pressure of Diagram of Gas (Ammonia) Compressor, 135 V. Tests of Priestman Oil Engine, . . . . 178 VI. Tests of 25 B. H. P. Hornsby-Akroyd Oil Engine, 186 VII. Relative Cost of Installation and Operation, Gas, Steam and Oil Engines, . . . . 209 VIII. Tests of Diesel Engine, 220 IX. Characteristics of Oils, 234 X. Beaumont Oil, 234 XI.) XII. v Characteristics of Different Oils, . . . . 235 XIII. ) XIV. Calorific Power of Various Descriptions of Petroleum, 236 XV. Composition, Physical Properties, etc., of Various Descriptions of Petroleum, . . 237 XVI. Oil Fuel, 238 XVII. Calorific Power of Crude Petroleum, .. 238 XVIII ) VTV > Tests of Various Oil Engines . . . . 248-251 LIST OF ILLUSTRATIONS PAGE Abel Oil-tester 91 Air-compressing Outfit, Portable .... 204 American Oil Engine Co.'s Engine . . . 195, 196 Apparatus for Open Fire Test .... 91 Automatic Air Inlet- Valve ..... 41 Barker Engine ' . 197, 198 Beau de Rochas Cycle, Diagram .... 16 Britannia Co.'s Engine, Sectional Views to face page 192 Campbell Diagrams . ... . . . . 174 Campbell Vaporizer . ... to face page 12 Campbell Type Engine ...... 173 Cams, Air and Exhaust to face page 36 Connecting-rods . ... to face page ^30 Connecting-rod Bearings ...... 159 Connecting-rod, Phosphor-bronze .... 31 Cooling Water Tower to face page 98 Cooling Water Tower and Radiator . to face page 99 Cooling Radiator with Electrically Operated Fan At- tachment . . . . . to face page 99 Crank-shaft bearing . . . . to face pages 40, 54 Crank-shafts, Balanced to face page 28 Crank-shafts, Slab Type 27 Crosby Indicator ....... 68 Crossley Diagrams . . . . . . . . . 170 Crossley Vaporizer . . . r . . to face pages 4, 6 Crossley Type Engine ...... 169 Crossley New Type Engine . . to face page 170 Cundall Type Engine 171 Cylinders to face page 32 Cylinders to face page 26 Xviii LIST OF ILLUSTRATIONS. PAGE De la Vergne Engine, Sectional Views, to face pages 227, 228 De la Vergne Vertical Type 183 De la Vergne Vertical Type and Air Compressor . 128 De la Vergne Indicator Diagram .... 186 De la Vergne Indicator Diagram . . . 228, 229 Diagram of H. P. for Air Compressing . . . 130 Diagram of Valve-settings . . ... . . 60 Diagrams, Reversing Engine and Cams . . . 155 Diesel Motor 213, 214, 216, 219 Diesel Motor, Indicator Diagram .... 218 Diesel Motor, Sectional View . . to face page 212 Direct-connected Air-compressing Plant (Sectional View) 124 Dynamo Fly-wheel 116 Electric Spark Igniters to face page Engine and Dynamo, Belt-driven . . . . 112 Engine and Refrigerating Machine .... 132 Engine Connected to Water-pump . to face page 129 Engine Connected to Water-pump, Small Type . 131 Engine Foundation . . . . . . . 114 Exhaust Silencing Pit ...... 101 Exhaust Washing Device ...... 102 Fly-wheels . . . . . .to face page 34 Foundation and Oil Tank to face page 114 Friction-clutch . 138 Geared Air-Compressing Plant . . to face page 126 Governors to face page 48 Governors. Centrifugal Type . . to face page 44 Governor, Hit-and-miss Type ..... 47 Heating Lamp . ... . . . . . 142 Heating Arrangement . ... . . . 109 Hill Self-recording Speed Counter .... 85 Hornsby-Akroyd Engine and Dynamo . 118, 187, 188 Hornsby-Akroyd Horizontal Type . to face page 182 Hornsby-Akroyd, Sectional View . to face page 212 Hornsby-Akroyd Sprayer . . . to face page 10 LIST OF ILLUSTRATIONS. XIX PAGE Hornsby-Akroyd Vaporizer . . to face page 2 Hornsby-Akroyd Vertical Type 187 Hornsby-Akroyd 125 H. P. . . to face page 2IO Hornsby-Akroyd 250 H. P. CXI Engine Direct Con- nected to Compressor to face page 124 Indicator Cock ........ 66 Indicator Cards, Various to face page 24 Indicator Diagram ........ 76 Indicator Diagram ....... 77 Indicator Diagram ....... 79 Indicator Diagram ....... 80 Indicator Diagram ....... 82 Indicator Diagram, Light Spring .... 89 Indicator Diagram, Varying Pressures ... 46 Indicator Diagrams, Hornsby-Akroyd . . . 184 Indicator, Reducing Motion ..... 67 Johnston Oil Engine . ... to face page 190 Johnston Oil Engine Diagram . . . . . 191 Lucke & Verplank Vaporizer . . to face page 16 Lubricator ......... 58 Mietz & Weiss Oil Consumption Diagram . . . 179 Mietz & Weiss, Indicator Diagram .... 181 Mietz & Weiss Engine and Dynamo, Direct connected 120 Mietz & Weiss Type Engine . to face pages 178, 180, 210 Oil Engine with Testing Apparatus Applied . . 62 Oil-filter 49 Oil-pump ......... 144 Oil-Supply Pumps to face page 50 Pistons, Section of . . .to face page 32 Piston with Piston-rings ... . . . . 56 Planimeters 9. . - . . . . . . 7 2 Planimeter in position ...... 74 Portable Electric Lighting Outfit . to face page 202 Portable Oil Engine 202, 203 Priestman Engine ....... 176 Priestman Indicator Diagrams ..... 177 XX LIST OF ILLUSTRATIONS. PAGE Priestman Sprayer ........ 14 Priestman Vaporizer 13 Rites Governor ........ 189 Self-starter ......... 106 Silencing Device ....... 104 Sprayers, Oil . . . . . to face pages 14, 16 Spur-gearing 44 Starting Cam 143 Tachometer 84 Tachometer, portable 85 Testing Apparatus . . . to face pages 64, 65 Testing Oil-pump ....... 147 Traction Engine . . . . . to face page 204 Two-cycle Plan ........ 17 Valve-box ...... to face page 38 Valve-closing Springs to face page 42 Valve-levers 146 Valve Mechanism ....... 44 Valves, Air and Exhaust ...... 42 Vaporizer, C. C. Moore & Co. .... 222, 224 Vaporizer, Fairbanks-Morse . . to face page 224 Viscosometer ........ 94 Water-circulating Pump ...... 102 Water-cooling Tank and Connections .... 97 Worm Gear ........ 43 CHAPTER I. INTRODUCTORY VAPORIZERS, SPRAYERS, IGNITORS, CYCLES, ETC. THE oil engines treated of herein are internal com- bustion engines burning kerosene, fuel oil or crude oil, petroleum, coal oil, distillate, paraffine, etc. Such fuels have a specific gravity varying from 78 to 96 or 50 Beaume to 14 Beaume and have a flashpoint from 75 to 300 Fahr. The oil engines described are chiefly self-contained, that. is, they are gas engines with the addition of a vaporizing apparatus which can con- vert the fuels above referred to, either in the crude state as it issues from the ground, or in a semi-re- fined or refined state into vapor or gas within either the vaporizers or cylinders, ignite it with the conse- quent evolution of the heat stored in the fuel and con- vert same into power. The use of heavy oil for producing power in internal combustion engines appears to have received the at- tention of inventors as early as 1790, though no satis- factory practical kerosene or crude-oil engine is re- corded as having been made until about 1870. Those engines using the lighter grade fuels, such as benzine, gasoline, or naphtha, were commonly used previous to the invention of the kerosene-oil engine. The prob- 2 OIL ENGINES lem of efficiently producing a vapor and suitable ex- plosive mixture of air with such vapor, from these light oils was comparatively a simple matter. With the engine required to consume crude oil or the other fuels above named having a higher boiling point than gasoline and requiring different treatment to en- sure proper vaporization and to consume all parts of the heavier fuels, the problem of developing an appa- ratus to operate satisfactorily under all conditions and under changing loads was more complex. The following descriptions will show how efficiently and satisfactorily the present engines operate. IGNITERS. The first oil engines built had their charge of vaporized oil and air ignited by means of the flame igniter, which has, however, now entirely given place to the four following means of ignition : (a) Hot surface ignition, aided by compression. (6) Hot tube. (c) Electric igniter. (d) High compression only. The first-named type of igniter is illustrated in Fig. I. In this instance the heated walls of the vaporizer act as the igniter, aided by the heat generated during com- pression of the gases. The chamber being first heated, afterward the proper temperature is maintained by the heat caused by the internal combustion of the gases. The best-known vaporizer and igniter of this type is that in the Hornsby-Akroyd Oil Engine. Various other somewhat similar devices in which sufficient heat is maintained to cause ignition automatically are also now being made. The second type, that of the hot tube, is shown in 5 6 INTRODUCTORY. 3 Figs. 2 and 3. This igniter consists simply of a porcelain or metal tube fitted into the vaporizer or cylinder wall. It is closed at one end, the other end being open to the cylinder. It is heated by a lamp, as shown in Figs. 2 and 3, over part of its length. When compression due to the inward stroke of the piston takes place in the cylinder the explosive mixture is compressed into the tube and is ignited by coming in contact with the heated portion of it. Porcelain or nickel-steel tubes are preferable to wrought iron, all of which substances are used for this purpose. The electric igniter, which is at present more largely used for gas and gasoline engines than for oil engines, is shown in Fig. 4. Those illustrated are known as the "jump-spark" and the make-and-break types. The jump-spark (Fig. 4) is preferred for high speeds, as it has no moving parts inside the cylinder. With this type the igniter plug containing the termi- nals is screwed into the cylinder cover. The method of making electrical connections is shown in principle at Fig. 4. Connection is made from the battery through the primary circuit of the Rhumkorff or spark coil to the completely insulated spring which is operated by the cam. The other connection passes from the battery to the other spring operated by the cam-shaft or other moving part of the engine. The electrodes or terminals of the plug are connected to the secondary circuit. In operation where a vibrator is used in con- nection with the spark coil the cam at the proper time of sparking closes the circuit, causing a series of sparks to jump across the terminals in the cylinder and ignite the gases. 4 OIL ENGINES. The make-and-break type of igniter is shown in Fig. 40. This type consists of one well-insulated sta- tionary terminal and one terminal H mechanically operated. The ignition is caused by the separation of the two terminals, which produces a spark between them. Fig. 40 shows this igniter in connection with a magneto oscillator, which is frequently employed to furnish electrical current instead of the battery. With this apparatus the current is generated by the quick movement of the inductor, which takes the place of the armature in the ordinary dynamo, and which is caused to partly revolve by movement of the arm suit- ably actuated from the cam-shaft or other moving part of the engine. The magneto is a very simple device, consisting only of stationary steel magnets K, a cast- iron inductor which takes the place of the ordinary armature, and two coils imbedded in the frame. The action is as follows : The inductor arm C is raised by the roller A on the disc B attached to cam-shaft. The spring D, shown in Fig. 40, is compressed. When the arm is released the inductor has a quick, oscillating motion, caused by spring D, which produces a strong electrical current. This current passes through con- nection / to insulated igniter point, and through the movable electrode G back to the induction apparatus. The movement of inductor lever by the heavy spring allows the collar on rod E to hit the arm attached to movable electrode, thus separating the two electrodes and causing a spark to pass between them. A spark plug is shown in section at Fig. 4&, made by A. W. King. Advantages are claimed for this type INTRODUCTORY. 5 of plug because of the increased sparking surface of the terminal, which is formed of an inner knife-edged disc placed concentric within a thick-wall chamber, which constitutes the outer terminal. Other forms of electrical igniters are the New Standard and the Split- dorf jump-spark apparatus. The fourth-named type of ignition, that due to com- pression in the cylinder alone, is found only with the Diesel motor. Advantages are claimed for each of these igniting devices by the various manufacturers using them. The electrical igniter is easily controlled and is reliable, but the batteries in unskilled hands sometimes give trouble, and it is essential that the parts forming the contacts be kept clean and in good condition. The tube igniter always requires heating by the ex- ternal heating lamp, upon which it is dependent, like all types of vaporizers which require external heat; so likewise is also the tube dependent entirely upon it. The former difficulty with ignition tubes and their frequent bursting has now been minimized by the use of nickel alloy, porcelain or other material more suit- able than wrought iron for this purpose. The hot surface type of igniter formerly gave trouble caused by its temperature cooling down at light loads. This type, however, which has now been adopted in various forms, has been designed to overcome this dif- ficulty, and can now be relied upon to keep hot when running at light loads. VAPORIZERS. As already stated, the problem of efficiently vaporizing petroleum was the most difficult feature to encounter in designing oil engines. 6 OIL ENGINES. The present universal use of heavy oil engines is com- plete evidence of how any former difficulty has been thoroughly overcome, and examination of the various modern vaporizers shows extreme simplicity in operation. The fuels used in the oil engines here discussed (crude oil, kerosene, etc.), in order to be properly vaporized, require to be broken up into the form of mist or oil vapor by spraying, or by a current of air, and then heated to a temperature above the boiling point. The oil vapor must then be thoroughly mixed with air, in order to procure complete combustion. This process is performed by various methods, as is shown in the following description of vaporizers. The composition of various fuels is discussed in Chapter XIII. Several oil engines having a method of vaporization are now made where the oil is injected directly into the cylinder or where it is inhaled with the air, and where both are closely regulated similar to the Priest- man type of oil engine. The mixture of oil vapor and air being carried on by compression in the cylinder, ignition is caused by an electric or tube igniter. The heat from the exhaust is utilized to raise the tempera- ture of the chamber through which the oil passes to the cylinder, which, with the heat caused by compres- sion, is sufficient to cause vaporization and a proper mixing with the air to form an explosive mixture, the chamber, which is heated by the exhaust in operation being first heated by a lamp. Theoretically, the amount of air required for each INTRODUCTORY. 7 pound of kerosene or oil vapor is approximately 200 cubic feet at 60 Fahr. atmospheric pressure. From calculation of the amount of air taken into the cylinder, it will, however, be noted that this amount in practice is much greater. In some instances it is more than twice lhat amount, or 400 cubic feet. This greater volume of air is required owing to the presence in the cylinder, in operation, of a residue of the burnt products of previous explosions and to other impuri- ties causing the efficient combustion of the oxygen of the air with the oil vapor to be somewhat retarded. A method of starting the oil engine has of recent years been used in which alcohol, gasoline, or naphtha is burnt for a few minutes instead of kerosene. This method is advantageous in that the engine when cold can be started without the use of external heater. The lighter fuel is supplied to the vaporizer or cylinder un- til the vaporizing attachment has become heated by in- ternal combustion to the temperature necessary for vaporizing the heavier fuel ; then the fuel supply is changed, the supply of lighter fuel being stopped. Where an automatic igniter or vaporizer of Type 4 is used an independent electric igniter is employed to ignite the gases, and which is only in action until the vaporizer is heated. The different types of vaporizers have been classified as follows : I. The vaporizer into which the charge of oil is injected by a spraying nozzle being connected to cylin- der through a valve. 8 OIL ENGINES. 2. That into which the oil is injected, together with some air, the larger volume of air, however, entering the cylinder through separate valve. 3. That vaporizer in which the oil and all the air supply (passing over it) is injected, but being without spraying device. 4. The type into which oil is injected directly, air being drawn into the cylinder by means of a separate valve, the explosive mixture being formed only with compression. With each type of vaporizer some advantage is claimed, but corresponding disadvantage can perhaps be named. For instance, in type i, though the mixture of oil and air is more complete, and the vaporizing probably greater than in the other types, yet the system of having an explosive mixture at any other place than in the cylinder and at any other period than at the time of actual ignition may be urged as a great dis- advantage to this system. With class 4 the mixture of air and oil may not be so complete, and the initial pressure in the cylinder consequent upon explosion less than the pressure ob- tained with other types ; yet the extreme simplicity of this type is an advantage in daily use which cannot be overestimated. With class 2 the highest mean effective pressure is obtained and the lowest consumption of oil per H. P. is recorded, but where a heating lamp burning con- tinuously is required then on the heating lamp depends the efficiency of the engine itself. LUCRE AND VERPLANK VAPORIZER. An apparatus for vaporizing crude or fuel oil is shown at Fig. Jc ; it consists of a chamber containing liquid fuel surrounded FIG. 46. FIG. 40. FIG. 4. (To face p. 8) INTRODUCTORY. 9 by an exhaust heating jacket. The fuel is maintained at a temperature corresponding to its boiling point, and freely gives up vapor without overheating or carboniz- ing. The piping arrangement allows liquid oil to be constantly present in the chamber. The fuel enters at the bottom, and after vaporization, some is blown off through the connection leading to the condenser while the rest enters a mixing and proportioning valve sup- plying the engine with correct clean explosive mixture. If the load on the engine does not require the full amount of vapor, it is condensed. The lower blow-off cock allows the liquid residue carbon to be disposed of when crude or fuel oils are used. When using dis- tillate, kerosene, etc., the blow-off is dispensed with. Fig. yc shows the pressure type of vaporizer, but by breaking the pipe between condenser and feed and in- serting a constant level open cap, vapor is generated at atmospheric pressure, then one or both check valves are omitted. THE HORNSBY-AKROYD vaporizer is shown at Fig. I, and also as it is at present manufactured in Fig. 76, which illustrates a complete section of this engine. The oil in this method of vaporizing is injected through the spray nipple, as shown in Fig. 5, directly into the vaporizer by the oil-supply pump. The injec- tion of oil into the vaporizer takes place only during the air-suction stroke. The lever which actuates the air-valve also simultaneously operates the oil-pump. When the piston is at the outward end of the cylinder, the suction period being then completed, the cylinder is filled with atmospheric air, and the vaporizing chamber, which is at all times open to the cylinder, is also at the same time filled with oil vapor. The compression stroke of the piston then com- IO OIL ENGINES. mences; the atmospheric air in the cylinder is thus driven through the contracted opening between the cylinder and the vaporizer into the vaporizer itself, al- ready filled with the oil vapor. The oil enters the vaporizer in the form of a thin spray or sprays and impinges on the cast-iron vaporizer wall on the oppo- site side, and then forms a vapor which afterwards mixes with air. Two forms of oil injectors are shown in the accompanying illustration, Fig. 5a being that used in connection with the later type of Hornsby- Akroyd vaporizer, which is partly water- jacketed; in this type a circular passage is made through the water- jacketed part of the vaporizer, into which the oil-spray sleeve is fitted. The water circulating around the vaporizer maintains the whole at a low tempera- ture. Fig. 5 shows the older type of oil inlet sleeve and sprayer. Another form of oil injector made by the English makers of this engine is shown at Fig. 95. In this type the water jacket is eliminated, the heat be- ing carried away by the surrounding air and by the fuel passing through it as it is pumped to the vaporizer. The steel spray nozzle in this type is a loose piece, being held in place by the pressure of the studs holding the sleeve containing the valve against the vaporizer. After the oil is injected into the vaporizer the compression stroke commences as this proceeds; the mixture, which at first is too rich to explode in the vaporizer, gradually becomes more diluted with the air, and when the com- pression stroke is completed the mixture of oil, vapor and air attains proper explosive proportions. The mixture is then ignited simply by the hot walls of this FIG. 5. (To face />. 10.) INTRODUCTORY. II same vaporizing chamber and also by the heat gener- ated by compression. No other means of ignition is necessary. No heating lamp is required to maintain the necessary temperature of this vaporizer ; a lamp is, however, required to heat it for a few minutes before starting. THE CROSSLEY method of vaporizing. This vapor- izer is shown in section in Fig. 2. It consists of three main parts, the body, the passages, and the chimney cover. There are no valves about the vaporizer itself ; it is arranged to keep hot, and while not in contact with the cooled cylinder is near to the vapor inlet valve to which it delivers its charges. The passages inside which vaporization of the oil takes place are detach- able. The wrought-iron ignition tube is placed below the vaporizer communicating directly with the cylinder. A heating lamp is always required to heat the vaporizer and maintain the ignition tube at proper red heat. The method of vaporizing is as follows : When the suction stroke of the piston commences the oil inlet valve is automatically lifted from its seat and allows oil to be drawn into the vaporizer through it. The vaporizer blocks having been heated by the inde- pendent lamp, and likewise the chimney being hot also, heated air is drawn in passing first through the aper- tures in the sides of the chimney communicating with the passages of vaporizer blocks. The air is thus thor- oughly heated, and next it passes over the heated cast- iron blocks. To these blocks the oil also flows from the oil measurer. The heated air here mingles with 12 OIL ENGINES. the oil and vaporizes it, and the two together properly mixed are drawn into the cylinder through the vapor valve. Simultaneously, while the above process of vaporization is proceeding, air is also entering the cylinder through the air-inlet valve on the top of the cylinder. Thus, when the suction stroke of the piston is completed the cylinder is full of heated oil vapor drawn in through the vapor valve, too rich to explode by itself, and also atmospheric air drawn in through the air valve. Both elements are then compressed by the inward stroke of the piston completing the mixture of the oil, vapor and air. Fig. 3 shows the latest type of Crossley vaporizer which only requires heating when starting the engine. The fuel is injected directly into the vaporizer through the sprayer shown at C, Fig. Jo, placed on the side of the vaporizer. A small amount of water with some air also enters this vaporizer. Fig. 6 represents the Campbell vaporizer in section. The fuel oil is fed to the vaporizer by gravitation from the fuel tank placed above the engine-cylinder, and enters the vaporizer with the incoming air. At the be- ginning of the suction stroke the automatic air-inlet valve is opened by the partial vacuum in the cylinder, and the oil which has entered through the small holes at the inlet valve is drawn through the heated vaporizer into the cylinder. At the compression stroke the mix- ture of the vapor is completed, and being forced into the ignition tube is ignited in the ordinary way. The ignition tube is heated by heating lamp fed by gravita- tion from the oil tank. The same lamp also heats the OIL INLET FIG. 6. (To face />. 12.) INTRODUCTORY. 13 vaporizer as well as the tube. The governing is effected by allowing the exhaust-valve to remain open when the normal speed is exceeded ; consequently no charge is in that case drawn into the cylinder. SPRAYERS. The oil-spraying device of an oil engine is an important feature. In some engines the fuel is sprayed alone into the vaporizer. In others with the highest thermal efficiency compressed air is injected with the fuel. Various sprayers are shown at Fig. 70 and 7&. That at A is positively operated and allows air and fuel to enter the vaporizer together ; those at B and C are automatic and only fuel is sprayed. The method of vaporizing the oil with the PRIEST- MAN engine is as follows : The oil is stored under pressure in the fuel-tank, which pressure is created by the separate air-pump, actuated from the cam-shaft. The oil is thus forced to the sprayer, which device is shown in Fig. 6a, where it meets a further supply of air. The mixing of the air and oil takes place just as both elements are injected 14 OIL ENGINES. into the vaporizing chamber, as shown in Fig. 6a. The heating of the vaporizer is first accomplished with sep- arate lamp ; afterward, when the engine is working, the exhaust gases heat the vaporizer by being carried around in the outside passage of the vaporizer cham- A. o. FIG. 7. "A" Air pump connection, "o" Air passage to spray- maker. "O" Oil tank connection. 'V Oil passage to spraymaker. "B" Supplementary air valve. ber, as shown in Fig. 6a. On the outward or suction stroke of the piston the mixture of oil vapor and air already formed and heated in the vaporizer is drawn into the cylinder through the automatic inlet-valve shown on the left of Fig. 6a. The compression stroke INTRODUCTORY. I 5 then takes place in the ordinary course of the Beau de Rochas cycle. The governing is effected by means of the pendu- lum or centrifugal governor, shown at Fig. 7, control- ling the amount of air entering the vaporizer as well as reducing the supply of oil simultaneously. Thus, the explosive mixture is always composed of the same proportions of air and oil, but as the supply of air is thus curtailed the compression in the cylinder is also necessarily reduced when the engine is working at half or light load. The governor thus varies the pressure of the explosion, reducing it when necessary, but not causing at any time the complete omission of an ex- plosion. The system of throttling the pressure, somewhat similar to a steam engine, produces very steady run- ning. By this system a thorough vaporization of the oil takes place. The ignition of the gases is caused by electric spark- igniter, the spark being timed by contact-pieces ac- tuated from the cam-shaft and horizontal rod actuating the exhaust-valve, and is of the " jump-spark" type as shown in Fig. 4. The oil engines now in use and herein described are designed with their valve mechanisms arranged to work either on the Beau de Rochas cycle, or on the two-cycle system. These two cycles are variously des- ignated, the former being generally known as the Otto cycle, the four-cycle, and sometimes, but erroneously, the two-cycle. Correctly, it should be named the Beau i6 OIL ENGINES. de Rochas cycle after its inventor. The other cycle is generally known as the " two-cycle," or sometimes as the " single cycle," the first designation, however, being correct. With those engines working on the Beau de Rochas cycle, which includes now many if not all the leading and best known types of engine. S3* 1 ' THE BEAU DE ROCHAS CYCLE. the cycle of operation of the valves is as follows : (a) Drawing in the air and fuel during the first outward stroke of the piston at atmospheric pressure. (b) Compression of the mixture during the first re- turn stroke of the piston. (c) Ignition of the charge and expansion in the cylinder during second outward stroke of the piston. (J) Exhausting, the products of combustion being expelled during the second return stroke of the piston. These operations are clearly shown in the accom- panying illustration, and thus, in this system, the one cycle is completed in two revolutions of the crank- FIG. 7c. FIG. 7b OIL. lNL.r (To face p. 16.) INTRODUCTORY. shaft or during four strokes of the piston. The im- pulse at the piston is obtained only once during the two revolutions. The second system, named " two-cycle," is com- THE TWO-CYCLE PLAN. pleted in one revolution, or every two strokes of the piston, and is also clearly shown by the accompanying illustration. The operation of this type is as follows : l8 OIL ENGINES. (a) During the first part of the outward stroke of the piston that is, until the piston uncovers the ex- haust-port expansion is taking place. When the ex- haust-port is opened the products of combustion are expelled ; the piston then moves a little farther forward and uncovers the air-inlet port communicating with the crank chamber. The air at slight pressure at once rushes into the cylinder, assisting the expulsion of the burnt gases, and filling the cylinder with air already compressed to five or six pounds in the crank chamber ; this completes the first stroke of this cycle. (&) The next stroke (being the inward stroke of the piston) the supply of incoming air and fuel is first taken in; then compression of the charge takes place. Ignition follows when the piston reaches the back end. These two strokes of the piston, or one revolution of the crank-shaft, completes this cycle of operation. ADVANTAGES AND DISADVANTAGES OF BOTH CYCLES. The Beau de Rochas cycle engine, having only one impulse during two revolutions, requires the dimen- sion of the cylinder to be greater in order to obtain a given power than would be required with the two- cycle system. Large and heavy fly-wheels must also be fitted to the engine in order to maintain an even speed of the crank-shaft. On the other hand, this cycle has many advantages. The explosion is con- trolled more readily. The idle stroke of the inlet air cools the cylinder and allows sufficient time to entirely expel the products of combustion, and with this sys- INTRODUCTORY. 19 tern no outside air-pump is required, nor is there any fear of the compression being irregular by leakage in the crank chamber or otherwise. With the two-cycle system air must in some way be independently compressed. If this is accomplished in the crank chamber, then leakage may occur and bad combustion follow, with accompanying bad results to valves and piston. More cooling water is also needed to cool the cylinder, and the proper lubrication of the piston may consequently be very difficult to accom- plish. With this system steadier running is obtained, nor are the heavy fly-wheels required as with the engines of the Beau de Rochas cycle. Large sized oil engines by all leading makers are now made of the four (or Beau de Rochas) cycle. Few if any two-cycle oil engines are now on the market where over 35 B. H. P. is developed in one cylinder. The increased volume of heated gases or vapor in the larger diameter cylinder precludes the successful opera- tion of the two-cycle type where the explosion occur- ring each revolution render the cylinder difficult of proper cooling. In such engines, where the pressure of compression takes place in the crank chamber, difficulty is also experienced with the heating of crank and other bearings. In the smaller sizes the two-cycle type has many advantages notably greater frequency of im- pulse, decreased weight per H. P., elimination of ex- haust valves and valve motion. From tables of tests* it will be noted the economy of the four-cycle is higher than that of the two-cycle type. *See pages 249 to 252. CHAPTER II. DESIGN AND CONSTRUCTION OF OIL ENGINES. THE designing of an oil engine is generally a differ- ent procedure from that of designing a gas engine. It is true, the oil engine is a gas engine in the strict sense of the term, but with the gas engine proper, the fuel enters its cylinder or mixing chamber in a gaseous state ready for mixture with the air. The power which the gas engine will develop can more readily be calculated when the clearance and pressure of compression before the explosion is known than with the oil engine. The special apparatus which is the most important part of the oil engine is the vaporizer. The different types of vaporizers and the various methods of vapor- izing the fuel have already been described and ex- plained in Chapter I. In practically all the oil engines herein described the vaporizing apparatus is self-contained in the engine and part of it. Before the pressures which will be de- veloped in the cylinder can be accurately computed, experiments may be necessary to develop the allowable maximum pressure of compression which can be used to obtain properly timed ignition, complete combustion and highest fuel economy. These remarks are particularly applicable to the type of oil engine having automatic or "hot surface" igni- tion. In those engines where the electric ignitor or ON DESIGNING OIL ENGINES. 21 other mechanically controlled ignitor is used, or in the type where the injection of the fuel takes place after compression is completed, the exact timing of ignition is positively controlled and with the engine in proper working order in other respects pre-ignition cannot take place which might result with the type having automatic or "hot surface" ignition. In this chapter it is intended only to describe as fully as possible the practical details of the construction of the oil engine. For a theoretical discussion of the thermodynamics of the internal combustion engine, the reader is referred to those works devoted to that subject.* Briefly referred to, the ideal heat engine converts into work the fraction of heat r, - Where T 1 = absolute initial temperature or recep- tive temperature. T^ = absolute final temperature or rejec- tive temperature. The oil engine, like all other heat engines, converts into work that amount of heat being the difference be- tween the initial temperature or heat received and the final temperature or heat equivalent of exhaust and other losses. Thus Heat evolved = work f -f- heat and other losses. *The Theta Phi Diagram by H. A. Golding ; the Steam En- gine by J. H. Cotterill, and Heat Engines by Prof. Ewing. tHeat equivalent of work is I. B. T. U. = 778 Foot pounds. 22 OIL ENGINES. In order therefore to obtain the greatest economy, the greatest range of temperature must be allowed be- tween the initial and final temperatures. For this rea- son the progress towards higher economy witnessed in recent years in the oil and gas engine has been largely if not entirely effected by the use of greater pressures of compression before ignition, where the initial tem- perature which is a measure of the heat received by the engine has been increased, while the final temperature has remained with little or no ^ increase, the range be- tween being accordingly increased. HEAT LOSSES. In the equation above, the heat or other losses may be classified as follows: i. Friction in the mechanical movements of the engine itself. 2. Losses of heat through the cylinder and other water jackets. 3. Radiation. 4. Loss through exhaust gases. 5. Leakage and other losses. INTERNAL COMBUSTION ENGINES are of substantial design in order to withstand the continual shock and vibrations incident thereto, and should pre-eminently be as accessible as possible in the working parts, which may require adjustment from time to time when in ac- tual service. The starting gear and other parts to be handled by the attendant when starting and running should be placed in close proximity to each other. Simplicity in construction is, in the writer's opinion, the essential feature of an oil engine. Above all other prime movers, the oil engine is a machine intended for use in any part of the world where its fuel is obtain- able, and where, perhaps, no mechanic is available. FIG. 8. (To face p. 22.) ON DESIGNING OIL ENGINES. 23 Accordingly, all the valves should be arranged so as to be easily removed for examination and repairs. The spraying and igniting device, as well as the vaporizer, should be so designed as to facilitate removal and re- pairs. In short, an oil engine, to be successful mechan- ically and commercially, should be so constructed that it can be successfully worked, cleaned and adjusted by entirely unskilled attendants. THE INDICATED HORSE-POWER (I. H. P.) or total power developed by the engine is arrived at by the formula 33,000 Where P = mean effective pressure in Ibs. per sq. in. L = length of stroke in feet. A = effective area of piston in sq. in. N = number of explosions per minute. THE BRAKE OR ACTUAL HORSE-POWER (B. H. P.) developed by the engine is the I. H. P. less the friction in the engine itself and depends upon the amount of power absorbed. The mechanical efficiency of the en- gine (see page 86) is found by the formula Mech. Em. (E) = 5. In determining the diameter of the cylinder of an engine to furnish a required actual or Brake H. P., the diameter of the cylinder must allow for the friction losses, the mechanical efficiency being usually 80% to 24 OIL ENGINES. The mean effective pressure (M. E. P.) may be ar- rived at by the following formulae in existing engines : B. H. P. X 306.000 Mean effective pressure = --- 'v FX N E= Mechanical efficiency, usually about 0.80. F= Volume piston displacement in cubic inches. N '= Number of explosions per minute. For multicylinder engines, the M. E. P. can be de- termined by considering the B. H. P. for one cylinder only. The accompanying diagrams, Fig. 8b, are taken from different makes of oil engines which have various pres- sures of compression. It will be seen that while there is a certain comparison between the compression pres- sure and the maximum and mean effective of the oil engine the rules laid down for the gas engine do not altogether apply to the oil engine. The formulae given hereafter are those in many in- stances used for the designing of gas engines. The dimensions of the reciprocating parts are frequently, however, increased somewhat for the oil engine, es- pecially with the type having hot surface or automatic methods of ignition. CYLINDERS. Cylinders of different types are shown at Figs. 8, 8a, and 9. Where the cylinder is made in two parts the inner liner is held at the back end only, the front joint being made with rubber rings. This leaves the inner sleeve free to expand lengthwise and FIG. 8b. (To face p. 24.) ON DESIGNING OIL ENGINES. 25 also allows the strain of the explosion to be transmitted only through the outer cylinder. Except for the larger- sized engines of over 40 H. P., the cylinder made in one piece is very satisfactory. The circulating water space around the cylinder is made as is shown in Figs. 8 and 9, being f " to iV' deep, the water inlet and outer pipes being so arranged as to allow free and efficient circulation of the cooling water around the cylinder. By some manufacturers this space for water is arranged to cool only that part of the cylinder cover- ing the travel of the piston-rings, instead of the whole cylinder, as here shown. Other cylinders are cast in one piece with the frame or bed-plate having internal 'sleeve. This arrangement has, among other advan- tages, that of cheapness, but it has the disadvantage that if the cylinder for any reason should require re- newing the whole frame must be renewed with it. The cylinder cover is made in some engines with the valves, air-inlet valve housing or guide inserted into it, and with space also in the larger-sized engines ar- ranged for cooling water-jacket. Other engines have the igniter placed in the cover, while cylinders of the type shown in Fig. 8 require no cover, the vaporizer flange closing the contracted hole in the end of the cylinder. CYLINDER CLEARANCE. The percentage of clear- ance or clearance volume in the cylinder and combus- tion space may be arrived at by the following : 26 OIL ENGINES. Where V c = clearance volume in cubic inches. P e = compression pressure in atmospheres _ absolute pressure 14.7 d= diameter cylinder in inches. s = length of stroke in inches. The clearance allowed with the oil engine will de- pend upon the type of vaporizer and the method of vaporizing adopted, on the timing of the injection of fuel, the pressure of compression and the clearance may finally have to be modified to procure the best re- sults as shown by the indicator card. STROKE. The ratio of length of stroke to diameter of cylinder varies with different types of engines. The maximum speed of piston allowable is considered 900 ft. per min. In small high speed engines the length of stroke -r: r r= , = I. tO I.*. diameter of cylinder For medium sized engines this ratio is 1.3 to 1.6, while in larger engines the ratio is sometimes as large as i. 8 or 2. THE CRANK-SHAFT of an oil engine must be made of sufficient strength not only to withstand the sudden pressure due to ordinary explosion, but also to with- stand the strain consequent upon the greater explosive pressure which may possibly be caused by previous missed explosions. The crank-shaft is proportioned in relation to the area of the cylinder and the maximum pressure of explosion and the length of stroke. .Oil-en- gine crank-shafts are usually made of the "slab type," as shown in Fig. 10. It has been said of explosive engines that their comparative efficiency may be to an extent ON DESIGNING OIL ENGINES. 2/ gauged by the strength of the crank-shaft, because if the crank-shaft is of too small dimensions, it will spring with each explosion, causing the fly-wheels to run out of truth and also uneven wear of the bearings. Table I. gives a list of dimensions of crank-shafts of both oil and gas engines which are made by some leading manufacturers, together with the dimensions of the cylinder and stroke. Different formulae for the dimensions of crank- FIG. io. shafts are given by various writers on this subject.* The following, for example (which is recommended by the writer), is given by Mr. William Norris. sxt 120 S = load on piston (area of cylinder in inches X maximum pressure of explosion. / length of stroke in feet. D = diameter of crank-shaft in inches. *An alternative formula is D = 0.137-^5 X /. OIL ENGINES. This formula, however, neglects the bending action due to the distance of the centre of crank-pin from the centre of the bearings. The diameter should be thus slightly increased. Mr. Norris also gives a lengthy description, with example, of ascertaining all the dimensions of the crank-shaft by means of the graphic method. TABLE I. SIZES OF CRANK-SHAFTS. Cylinder. A. B. c. D. E. F. G. Diam. Stroke. in. in. in. in. in. ft. in. in. 5 8 If I| 4 4 2 6* *i si 9 *i 3 4i 2* f 8| si 7i u 2* Si Si 2f 3 9^ 4i i 15 Si 4 7i I Si i 5 8* 18 si 4 9 3 Si 2 5 9i 18 si 4i 9 si si 3 Si 12 18 4i 4t 9 si.- 4i Si 6i Ili 21 4i 4l I0 i 4 si Si 6i 14 21 5i 5t !0i 4i 4i 5 8| 17 24 7 8 12 5t 7i ioi 10 19 3 7i 8 T 3 6 9 2 ii 7 12 *& 2f 6 *A 4 8f 3l 9 14 *H 3 7 2i 3t 4 ii 15 3 T V 4 71 2 T V 4i i 4f 'Si 16 sH 4f 8 3A 4| I3f 5l THE BALANCING of crank-shafts and reciprocating parts is another important feature of an oil engine. With a single-cylinder explosive engine to perfectly accomplish the balancing is impracticable. Most manu- facturers, therefore, only balance their engines as far FIG. n. (To face p. 28.) ON DESIGNING OIL ENGINES. 29 as the horizontal movement is concerned. The follow- ing formulae is considered correct, and has proved satisfactory for the horizontal type of engines : tc; =: weight in Ibs. of balance weight. C = crank-pin and rotating part of connecting-rod in Ibs. R radius of crank circle in inches. G two-thirds weight of all remaining reciprocat- ing parts in Ibs. .S weight of crank-arms in Ibs. r = distance of centre of gravity of crank-arms from centre of rotation. a = distance of centre of gravity of counterweight from centre of rotation. Some designers, however, the writer has observed, make the crank balance weights as large as space be- tween bearings and engine bed will allow that is, when the weights are fastened to the crank-arms, as shown in Fig. n, thus overbalancing the crank and reciprocating parts. While this would appear bad practice, such engines have been known to run without the slightest vibration. For the vertical type of engines the whole weight of the reciprocating parts, instead of two-thirds weight, has been satisfactorily taken. Reciprocating parts are sometimes balanced by re- cess in fly-wheel rim or metal added to the fly-wheel rim or hub. The only correct method of balancing is by counterweights. See Fig. 1 1 . 30 OIL ENGINES. Various methods of attaching the counterweights to the crank-shaft are shown at Fig. n, from which it will be noted that -the counterweights are attached by studs placed in the cheek of the crank and either pass completely through the counterweight or the counter- weight is recessed, the nuts of the studs being tightened in the recess as shown. Again one bolt only is some- times used, the cheek of the crank-shaft then being re- cessed, a lip being machined on the counterweight to fit the recess in the cheek of the crank-shaft. The fourth method of attaching the counterweights is shown, in which a bolt is placed at right angles to the center line of the countershaft, this bolt passing through a hole drilled in the counterweights and cheek of the crank-shaft. The two last named methods are chiefly used in the larger sized engines. The strength of the bolts neces- sary to hold- the counterweights in place can be found by the following formula : 13,020 Where w = weight of one counterweight in Ibs. r = distance from center line of shaft to center of gravity of counterweight in inches. n = revolutions per minute. d= diameter of each bolt in inches. The above is for two bolts for each weight. If one bolt only is used it must equal in tensile strength the two bolts. FIG. 12. (To face p. 30.) ON DESIGNING OIL ENGINES. 3! CONNECTING-RODS are made of various designs in cross-section, but that chiefly used is made of soft steel and circular, with marine type brasses at crank-pin end and similar bearings at the piston or small end. By some makers the latter bearing is made with adjust- able wedge and screw, the end of the connecting-rod then being slotted out, with brass bushes fitted in it. Each type of connecting-rod is shown at Fig. 12. That illustrated at "A" is a design more suitable for the larger size engines, in which space inside the pis- ton is available for adjustment of the bolts, as shown. The connecting-rod marked "B" is of the rectangular type, and is frequently left rough, the ends only being machined. FIG. 13 For small engines a good and cheap form of con- necting-rod is made of phosphor-bronze metal, as shown in Fig 13, from which it will be seen that the piston-end bearing is made in one piece with the rod, and being slotted is thus made adjustable. The metal is left rough other than at the bearings. CONNECTING-ROD BOLTS. The connecting-rod bolts 32 OIL ENGINES. should be made of the best wrought iron. The cross- section of connecting-rod bolts at bottom of threads must be such that on the beginning of the suction stroke the stress does not exceed 4,000 to 6,000 Ibs. per square inch. The total force is made up of the inertia force and the suction force and is arrived at as follows : Let F= total inertia force. d diameter of cylinder in inches. W= total weight of piston, piston pin, one- half the weight of connecting-rod and the weight of any cooling water in the piston. r = radius of crank in feet. /= length of connecting-rod in feet. Then F= .00034 W(R. P. M.)v(i + 0, and the suction force about 2 Ibs. per square inch. Therefore the total suction force A = 2 x .785^'. The area of all the connecting-rod bolts at the root of the threads should not be less than . 6,000 The connecting-rod of a single-acting engine has, chiefly, compression stresses to withstand ; both the outer end bearings have little or no strain on them, except that due to momentum of the reciprocating parts. The connecting-rod should be from two to three strokes in length. In computing its strength, the connecting-rod can be taken as a strut loaded at either end. The mean diameter when made of mild L BHH C FIG. 14. FIG. 140. FIG. 15. (To face p. 32.) ON DESIGNING OIL ENGINES. 33 steel is arrived at by the following formulae, as given by authorities on steam-engine design : x = 0.035 ^DlVm. x = mean diameter of connecting-rod (half sum of diameter of both ends). D = diameter of cylinder in inches. / = distance in inches between centre of connecting- rod. ' m = maximum explosive pressure in Ibs. per square inch. This formula, however, is excessive for medium and slow speed engines, and in such instances the writer has used the following formulae with satisfac- tory results namely : 0.028 YD I Vm. THE PISTON in single-acting engines is generally of the trunk pattern, as shown in Fig. 14, with internal gudgeon-pin placed in the centre of the piston, secured at either end to the piston by set-screws. The steam- engine cross-head and slide-bars are dispensed with, the power being transmitted directly from the gudgeon- pin of the piston to the crank. The piston is made of hard close-grained iron, and should not be less than 5-16" in thickness for small engines and slightly heavier for the larger sizes. In 34 OIL ENGINES. each case the metal is thicker at the back than at the front end. The piston is usually 1.6 diameters in length. Three cast-iron piston-rings, as shown in Fig. 15, are fitted to the smaller engines, four and five rings being required to keep the piston tight in the larger sizes. A single ring is sometimes added, placed in front of the gudgeon-pin, but its use is not recom- mended. The pressure on the piston, caused by the explosive pressure and due to the angularity of the connecting-rod, should not be greater than 25 Ibs. per square inch of rubbing surface. The piston in which separate distance-pieces be- tween each ring and having separate plate bolted to the back of the piston is shown at Fig. 140. In the larger engines (those having a cylinder diameter of more than 24 inches), a water- jacketed chamber is made at the back end of the piston which is supplied with a continuous flow of cooling wa'er. This piston is shown in section at Fig. 15 and Fig. 95. The cooling water is conducted to and fro by separate pipes attached to the piston, as shown in the illustration Fig. 95, and communicate either through stuffing boxes or other suitable means to allow proper supply of wa- ter to the piston. Water- jacketing of the piston is necessary in the larger sizes because of the increased volume of burning gases which would become unduly heated, allowing increased expansion of the piston and rendering it difficult of lubrication. PISTON SPEED. The revolutions per minute at which the engine is designed to run is governed almost entirely by the piston speed. High speed engines are designed with a comparatively short stroke slow speed I OX DESIGNING OIL ENGINES. 35 engines having a stroke much longer in comparison with the diameter of the cylinder. The maximum al- lowable cpeed of the piston is considered as 900 feet per minute. As in four-cycle engines the operation of the valves takes place only every other revolution, this type of engine is made with a speed frequently as high as 350 to 400 R. P. M. Inertia force per square inch of piston at end of compression stroke must' not exceed compression pressure, or the explosion will reverse the direction of pressures and cause a "knock." The inertia force per square inch of piston will be as follows: F_. 00034 W(R. P.M.) 3 / r\ a- a y + ir a = area of piston in sq. in. The value of must be such as to be less than the a compression pressure. FLY-WHEELS. The oil engine is equipped with heavier fly-wheels than is necessary with a steam en- gine. The weight of the oil engine fly-wheel varies in- versely both with the number of impulses given per revolution at the crank-pin and the degree of unsteadi- ness from the uniform speed of rotation allowed. The total revolutions per minute are controlled by the governor, but the cyclic variation and the degree of un- steadiness from uniform speed of rotation during one cycle depend on the fly-wheel. For a given degree of unsteadiness of a single cylinder, single acting four- cycle engine, the heaviest fly-wheel will be required. 36 OIL ENGINES. Where the number of cylinders is increased, or where the number of impulses per minute are increased, the weight of the fly-wheel to give the same degree of un- steadiness will, of course, be less than with a single cylinder engine previously referred to. By the degree of unsteadiness is meant the change in speed from the uniform speed of rotation through- out the cycle. Let T= Degree of unsteadiness. V max V min Then 1 = ^7 . Kave V max = maximum velocity of shaft during cycle. V min = minimum velocity of shaft during cycle. F ave = average velocity of shaft during cycle. The value of T recommended by Giildner* is: .05 to .0334 ^V to -jV for pumps and wood factories. .0285 to .025 -fa to T V for factories. .025 -fa for looms and paper mills. .020 -gig- for grinding mills. .0166 to .001. . . .-gij- to Y^-JJ- for spinning factories. .00067 y-^ for direct-current gen- erator. .00033 TOT f r alternating-current generators. By cyclic variation is meant the greatest angle that the rotating crank-pin varies from the position it would occupy were its motion perfectly uniform. Generally these two conditions are not related. Consideration of *Verbrennungs motoren H. Giildner. Page 345. ON DESIGNING OIL ENGINES. 37 cyclic variation is usually only necessitated when the engine is required to operate alternators in parallel or where a similar uniform motion is necessary. The diameter of the fly-wheel is governed by the peripheral speed which should not exceed 6,000 ft. per min. for cast iron. In computing the weight of the fly-wheel, it is customary to neglect the weight of the hub and arms, and to calculate only on the weight of the rim as follows : W weight of rim only in tons (2,000 Ibs.). D = dia. of the center of gravity of rim in feet. JV revolutions per minute. P= actual or brake H. P. C = constant. p Thpn W C u )*TN 3 ' C*= for single-acting 4-cycle engine with impulse each 720, 520.000. = for engines with impulse each 360, 250.000. = for engines with impulse each 240, 166.000. = for engines with impulse each 180, 83.000. Different types of fly-wheels are shown at Fig. 16. The smaller engines for industrial purposes are equipped with one and sometimes two fly-wheels made in one piece. Larger engines of say 50 H. P. and up- wards are usually equipped with one large fly-wheel made in two parts as shown at Fig. i6a. The hub split with medium sized wheels is considered advantageous, as it allows more accurate fitting to the shaft and it be- comes easier to keep the wheel running in truth. The cams are made of cast iron or steel and are usually designed as shown in Fig. 17. Cast iron is ad- 38 OIL ENGINES. vantageously chilled to withstand the wear of the rollers. The function of a cam is to transfer rotary mo- tion of the crank-shaft and cam-shaft to the recip- rocating action required for lifting the poppet valves. The rapid opening and closing of the valves necessary in a four-cycle engine is more easily arrived at with a cam motion than otherwise. The valve is closed by a spring, the function of opening the valve being per- formed by the cam only. Generally valve mechan- isms in which cams and poppet valves are used are noisy in operation, especially in higher speed engines. The rate of opening and closing of the valve can be ascertained by plotting a curve corresponding to ordi- nates equivalent to the various distances from the face of the cam to its centre taken at specified intervals. The required width of the face of the cam in contact with the rollers is ascertained by computing the work to be done due to the pressure in the cylinder at time of valve opening, together with the area of the valve. Accordingly, where the air valve is operated the cam controlling its movement is of less width, seeing that only atmospheric pressure obtains when it is operated as compared with the exhaust valve cam, which has to open that valve against a pressure in some cases as high as 40 Ibs., necessarily involving considerable work. VALVES AND VALVE-BOXES. The dimensions of the air-inlet and exhaust valves are governed by the diam- eter of the cylinder and the piston speed. The style of the valve-box recommended is that made separate and bolted to the cylinder. The valve-box can then ON DESIGNING OIL ENGINES. 39 be entirely renewed if necessary and at small expense. This type of valve-box is shown at Fig. 18, both valves being operated from the cam-shaft. The springs re- quired to close the valves are shown at Figs. 18 and 19. The latter arrangement has the advantage of having the springs placed away from the heated valve cham- bers. Other designs of valve chambers have the valves placed horizontally in the cylinder back-head. A com- pact design of valves is shown at Fig. 20, in which the exhaust valve is operated only, the air valve being au- tomatic. In each case the valves should be brought as close as possible to the cylinder walls, the clearance space in the ports, etc., being reduced to a minimum. With engines of larger size the air and exhaust valve box is surrounded by a water jacket, which maintains its proper temperature and prevents the seats of the valves being distorted by undue expan- sion, which might otherwise occur. It will be noted in the illustration that the inlet and outlet water con- nections to the valve-box are made by separate pipes. Where the air-inlet valve is made automatic, it is opened by the partial vacuum in the cylinder during the suction period, and closed by a delicate spring, as shown in Fig. 20. The air and exhaust valves and port openings are usually made of such an area that the velocity of the air inlet as it enters the cylinder is 100 feet per second the velocity of the exhaust gases through the exhaust or outlet being about 80 feet per second, presuming the exhaust products to be expelled at atmospheric pressure. The air-inlet valve, if auto- matic, should be so arranged as to allow ingress of air 4O OIL ENGINES. without choking. In calculating the area of valve ports or passages, allowance must be made for valve guide or other obstruction in the passages. The ve- locity of the air is found in the following formulae : V= velocity of air in ft. per second. P piston speed in ft. per second. a = area of piston in inches. a t = area of valve opening in inches. MAIN BEARING. Various designs of bearings are shown at Fig. i8a. The ring oiling type of bearing, while somewhat more expensive to manufacture than the other types shown, is recommended. The maximum pressure on the bearing should not exceed 400 Ibs. per sq. in. of projected area. THE CRANK-PIN. To determine the dimension of the crank-pin would properly lead to a lengthy discus- sion as to all the strains involved, and the reader for a complete discussion on this subject is referred to works where space is allowed for such.* In different types. of engines the dimension of the pin varies. A crank-pin short in length and compara- tively large in diameter is recommended. The diameter of the pin being not less than 1.2 times the diameter of the shaft. (See table I.) The average pressure on the crank-pin allowable should not exceed 500 Ibs. per sq. in. of projected area. *Unwin Machine Design. FIG. i8a. (To face p. 40.) ON DESIGNING OIL ENGINES. 41 THE EXHAUST BENDS close to valve-box should when possible be of not less than 5" radius for the smaller engines, which dimension should be increased for larger-sized engines. THE VALVES are made of forged steel, either in one piece or with cast-iron valve and wrought-iron or steel stem fitted into it, and are shown in Fig. 21. Some manufacturers prefer the latter on account of cheap- ness, and also because it is claimed the cast-iron valves will withstand heat better than the forged valve. from FIG. 20. PISTON-PIN. For small engines, the length of the piston-pin is almost invariably one-half the diame- ter of the cylinder and the diameter of the pin 0.15 to 0.25 the diameter of the cylinder. This leads to pres- sures of i, 800 to 2,200 Ibs. per sq. in. of projected 42 OIL ENGINES. Medium power and large engines have piston-pins of diameter minimum dp = o. 22d\vhered= diameter of cylinder, maximum dp = 0.45^. Lucke recommends a pin of diameter* and of length ^I^. WATER COOLED VALVt FlG. 21. THE ENGINE FRAME. Different designs of engine frames are shown in the illustrations of sectional views *Gas Engine Design by C. E. Lucke, Ph.D. ON DESIGNING OIL ENGINES. 43 of various engines (see Figs. 76, 98, no). The frame should be proportioned not only to prevent vibration and to withstand the strains consequent on the impulse in the cylinder, but should also be ribbed and of ample sectional strength to overcome the vibration known as "panting." VALVE MECHANISMS. With the Beau de Rochas or four-cycle engine the valves are only operated dur- ing alternate revolutions of the crank-shaft. This necessitates an arrangement of some kind of two-to-one gear. Worm-gear, as shown in Fig. 22, is considered FIG. 22. to be well adapted for this work. The power necessary to operate the valves is, in this case, transmitted from the crank-shaft by the worm or skew gearing through the cam-shaft, with separate cams opening the air and exhaust valves by the operating levers, as shown in Fig. 23. Where spur-gearing (Fig. 230) is .used the cam-shaft is mounted in bearings parallel to the crank- shaft, the cams then acting on the horizontal rod working in compression, which opens the valves. Various other arrangements for reducing the motion are also used, the work accomplished being in each 44 OIL ENGINES. case the same as with the worm or spur gear-, shaft and levers namely, the opening of the valves during al- ternate revolutions of the crank-shaft. LINE VALVE BOX FIG. 23. In the two-cycle engine this valve or valves are operated each revolution of the crank-shaft by eccen- tric or cams actuated directly from the crank-shaft. FIG. 230. GOVERNING DEVICES. The governing devices for controlling the speed of oil engines are of two kinds : first, that designed to develop centrifugal force, which ON DESIGNING OIL ENGINES. 45 is balanced either by suitable controlling spring or dead weight, as shown in Fig. 24, and, secondly, the inertia or pendulum type of governor. The accompanying illustrations also show the meth- od of by-passing the oil where the air supply is constant at all loads. The Rites governor, a very simple and efficient device of the fly-wheel type of governor, is illustrated and described in Chapter X., the method of governing, in which the air supply and oil supply is controlled, is shown at Fig. 7, illus- trating the Priestman governor. In those engines where the regulation is controlled by preventing the suction into the cylinder, caused by holding the ex- haust valve open, the inertia type of governor is some- times used, where the inertia of a weight attached to a reciprocating part of the valve motion is arranged, having its movement controlled by an adjustable spring. When the normal speed is exceeded the inertia of the weight overcomes the pressure of the spring and thus holds open the exhaust valve till the normal speed is regained. The governors regulate the speed of the engine by the following different methods : (a) By acting through suitable levers or other mechanism on the valves controlling the fuel supply to the cylinder, either by means of a by-pass valve placed in the oil-supply pipe to vaporizer, thus allow- ing part of the charge of oil to return to the tank in- stead of entering the vaporizing chamber or by regu- lating the amount of oil as well as the air supply. (&) Acting directly on the oil-supply pump, length- 4 6 OIL ENGINES. ening or shortening the stroke of the pump, as re- quired. (c) Where the oil vapor is arranged to be drawn into the cylinder with the incoming air the governor FIG. 25. acts on the exhaust-valve, holding it open during the suction stroke, thus preventing the inlet of vapor to the cylinder. (d) By acting on the vapor inlet-valve, allowing this valve to open only when an impulse to the piston is required. Engines driving dynamos for electric lighting and requiring very close regulation are preferably governed by the system of throttling or reducing the explosive pressures in the cylinder. Thus, when the engine ex- ceeds the standard speed for which the governor is set, only part of the vapor or oil is allowed to enter the ON DESIGNING OIL ENGINES. 47 vaporizing chamber or cylinder. The mixture of oil, FIG. 26. vapor and air is accordingly regulated, and the mean effective pressure as required is suitably reduced. 48 OIL ENGINES. The indicator diagram illustrates the variation of the M. E. P. in the cylinder, as shown in Fig. 25, each expansion line registering a different pressure. No explosion is in this case omitted entirely, and conse- quently the running of the engine is even and regular. A governor acting directly on the oil supply pump is shown at Fig. 240. Another type of governor operat- ing on the fuel oil pump directly is shown at Fig. 24^. In this instance the governor is placed within the fly-wheel and is also arranged to operate directly on the oil pump. It consists of frame F fastened con- centrically to inside of flywheel cam ring R, which has projection B and cam C projecting and operating each revolution (with 2-cycle type) on roller A, causing movement of plunger P. W is a wedge on lever L which separates R from F. If the speed is increased above normal the counterweight H overcomes the tension of spring S, moving the wedge outwards, allowing the buffer G to move from plunger P ; thus the lift of C is reduced and the length of pump stroke reduced. The hit-and-miss type of governor is shown in Fig. 26. This device is made in many different forms, the mode of working being similar in them all namely, the inertia of a weight controlled by the spring. When the speed of the crank-shaft is increased the weight is moved correspondingly quicker ; its inertia is then in- creased, and the strength of the spring is overcome sufficiently to allow the engaging parts of the valve ON DESIGNING OIL ENGINES. 49 motion to be disengaged during one or more revolu- tions, and consequently where this device acts on the oil-pump the charge of oil is missed, and no explosion takes place during the following cycle of operations. THE OIL-SUPPLY PUMP is placed against the oil-tank and base of engine or on bracket bolted to cylinder. It is usually made of bronze, with steel ball valves. Du- plicate suction and discharge valves are advantageous in case one valve on either side should leak. Figs. 27 and 28 represent oil-pumps as used on the Hornsby- Akroyd oil engine. THE FUEL OIL-TANK is placed in or bolted against FIG. 29. the base of the engine. It is then made of cast iron as part of the base of the engine; otherwise the tank is made of galvanized iron and separate from the engine 5O OIL ENGINES. base, so that it can be taken out when required for cleaning. A filter or strainer for cleaning the oil as it passes to the oil-pump which can be placed where convenient and is separate from the oil tank is shown at Fig. 29. HORIZONTAL AS COMPARED WITH THE VERTICAL TYPE OF OIL ENGINES. THE accessibility of the piston with the horizontal engine is considered a great advantage. The piston can always be seen and can be drawn out of the cylin- der and cleaned and replaced with ease in this style of engine, whereas in a vertical engine it is necessary to remove the cylinder cover, and perhaps other parts, to gain access to the piston, and also it is necessary to have sufficient head room above the top of the cylinder for chain-block to lift the piston and connecting-rod. The lubrication of the piston is also considered more effective in the horizontal than in the vertical type of engine. Furthermore, the connecting-rod is more ac- cessible for adjustment both at the crank-pin end and at the piston end in the horizontal type. This difficulty, however, has been overcome by arranging a removable plug in the cylinder casing, which when taken out allows access for adjustment to the piston end of the connecting-rod. European designers seem much in favor of the horizontal type of engines, and although some leading makers build the vertical type of engines, yet the greater number would appear to be made of the horizontal type. ON DESIGNING OIL ENGINES. 51 VERTICAL ENGINES for situations in buildings where space is restricted and where sufficient head room is available have the great advantage of occupying less floor space than the horizontal type. The mechanical efficiency of a vertical engine is somewhat greater, the friction of the piston being less than in the hori- zontal type of engine. The vertical type for some special purposes can, of course, only be used, but for ordinary uses the horizon- tal type of engine at present seems to be most in favor, one consideration being, the difficulty of suitably ar- ranging the vaporizing and spraying details in the vertical type of engine, which are usually placed close to the cylinder, and are, therefore, not so fully under the control of the attendant as in the horizontal type. MULTI-CYLINDER ENGINES. For industrial pur- poses and situations where simplicity of construction is of prime importance and where the engine will have little or no skilled attention, the single cylinder hori- zontal engine is preferred on account of fewer mov- ing parts. Objection is frequently made to a multi- cylinder or twin-cylinder engine on this account. The multi-cylinder engine, however, has the advantage that an impulse is received at the crank-pin with greater fre- quency than is the case with the single cylinder en- gine. For example, in the single four-cycle engine one impulse is received during two revolutions, while in the two-cycle single cylinder engine one impulse per revolution takes place. With the multi-cylinder engine, for instance, three-cylinder type, four-cycle 52 OIL ENGINES. single acting, three impulses are received by the crank- pin each two revolutions and with the three-cylinder two-cycle type six impulses in two revolutions. The multi-cylinder engine, therefore, has an important ad- vantage over the single cylinder type for such purposes as electric lighting and especially for operating alter- nating generators running in parallel where least pos- sible cyclic variation is required. Again, the multi-cylinder engine has the adavantage, considering that each impulse is more frequent, of not requiring the heavy fly-wheel necessary with the single cylinder type as explained on page 36. Undoubtedly the multi-cylinder type engine requires much more ad- justment of bearings than those of the single cylinder type. The multi-cylinder type being lighter in weight per actual horse-power can be manufactured cheaper per horse-power than can the single cylinder type. WATER INJECTION. The injection of a small amount of water, water vapor, or steam into the vaporizer or cylinder of the oil engine is now the practice of several makers. In the sectional view of the latest type of Crossley vaporizer, Fig. 3, is shown a water inlet valve to the vaporizer whereby a very small amount of water is injected into the vaporizer as well as air and fuel. The Priestman engine has an arrangement also allow- ing a small amount of water to be drawn into the combustion chamber when the engine is operating at full load. The Mietz & Weiss engine is arranged to allow steam formed in the water jacket surrounding the cylinder to enter the combustion chamber with the fuel. The ON DESIGNING OIL ENGINES. 53 advantages claimed for the injection of water, etc., are first, that the engine works more quietly with it than without. The heavy blow of the explosion and the metallic knock heard at full load is reduced ; and secondly, with the water injection a somewhat higher compression can be used without fear of pre-ignition ; and thirdly, the lubrication of the cylinder is assisted and the piston is maintained in a cleaner condition. The chief disadvantage is found when the supply of water is not very carefully regulated. The timing of ignition may be retarded or become irregular if too much water is admitted. TIME OF INJECTION OF FUEL. In the descriptive matter relative to the Diesel engine, page 216, it is pointed out that the injection of the fuel takes place after compression of the air in the cylinder is com- pleted. This was a feature peculiar to this engine. Several other makers are now adopting this feature; that is, increasing the compression and injecting the fuel as (or a few degrees before) the piston reaches the inner dead centre. The increased compression re- sults in increased economy and more complete com- bustion of the fuel. In the latest type Hornsby oil engines, in the De la Vergne F. H. type, and in the smaller 2-cycle type described in Chapters X. and XII. this feature is referred to. ERECTING AND ASSEMBLING OF OIL ENGINES. The following remarks relating to the erection of oil engines contain a few hints on important points of this work, the information being intended for those 54 OIL ENGINES. readers not sufficiently familiar with the assembling of explosive engines to be cognizant of the parts requiring careful handling and accurate workmanship. BEARINGS. In scraping in the crank-shaft bearings of horizontal engines the shaft must bear perfectly on that part of the bearings as shown in Fig. 30, marked FIG. 30. A, the greater pressure being on the part of the .bearing which is between the centre line of engine drawn through the cylinder and the part through which the vertical centre line of fly-wheel is drawn. A slight play of about 1-64" can be given to the crank- shaft sideways in the bearings in smaller-sized engines, and 1-32 of an inch in the larger sizes is recommended. ON DESIGNING OIL ENGINES. 55 In vertical engines the bearings receive both the pressure of explosion and the pressure due to the weight of the fly-wheels in the same part, and these bearings require the same care at those points in the lower half of the bearing namely, about 45 each side of the centre line drawn vertically through the cylinder and crank-shaft. The bearing surfaces of the caps and of that part where the pressure is not so great do not require such careful scraping as those parts where the pressure is greater. PISTON AND PISTON-RINGS. The fitting of piston and piston-rings is very important and requires accu- rate workmanship. The cylinder and piston are machined to standard ring and gauge, one-thousandth per inch diameter of cylinder play being allowed. The metal of the piston not being of uniform thickness after machining may slightly lose its shape, and some- times requires slight hand-filing when being fitted to the cylinder. The piston without rings can be moved easily up and down inside the cylinder. If necessary the piston should be eased slightly by hand on the sides, being left a good and close fit at the top and bottom bearing in horizontal engines. The sides should not rub hard in any part. The piston, if the rings are in place, can be fitted to the cylinder from the back end of the cylinder, and can be moved around the front end, being inserted into cylinder as far as the rings. THE DISTANCE-PIECES or junk-rings should not touch the sides of the cylinder, the bearing of the piston be- ing only on the trunk of the piston itself. The front OIL ENGINES. part of the piston can also be bevelled for f " in length, 1-32" in diameter, as shown in Fig. 14. THE PISTON-RINGS, if made as in Fig. 15, should have in the smaller sizes 1-32" play, in the larger sizes 1-16", as shown at A in Fig. 31. This space allows for expansion when the ring becomes heated in work- ing. It is advantageous to insert dowel-pins in the piston grooves to maintain the rings in the same posi- tion, so that the space in each ring is out of line with that in the following ring, as also shown in Fig. 31. /" A%^ i / \ L t 1, FIG. 31. THE PISTON is made in one piece, the rings being sprung on over the junk-rings. It should be remem- bered that with oil engines greater heat is evolved in the cylinder than in steam engines. Consequently the slightest play is allowed to the piston-rings at the sides, and are, therefore, not made so tight a fit as in steam- engine practice. THE CONNECTING-ROD BEARINGS at piston end are ON DESIGNING OIL ENGINES. 57 scraped in the ordinary way, and should be allowed slight play sideways on the gudgeon-pin. In smaller- sized engines 1-64" can be allowed, this amount being slightly increased in the larger-sized engines. The crank-pin bearing of the connecting-rod is usually allowed a very slight play sideways also. THE AIR AND EXHAUST VALVES should not be a very close fit in their guides. If the fit in these guides is made too close when the valve-box becomes heated the consequent expansion may cause the valve-stem to stick in the guides, and leakage of the valve will result. The valve-seats are by some considered best left sharp, being not more than 1-32" wide before grinding. THE WATER-JACKETS of cylinder or valve-boxes should be all tested -by hydraulic pressure to at least 1 20 Ibs. pressure per square inch before the piston is put into the cylinder. THE FLY-WHEELS require careful keying onto crank- shaft. If the keys are not a good fit and not driven home tight the engine may knock when running. Two keys in. larger-sized engines are usually supplied, one being a sunk key, which is fitted to keyway in recessed shaft as well as to the keyway cut in the fly-wheel hub, the second key being only recessed in the fly-wheel and being concave on the lower side to fit the shaft. OIL-SUPPLY PIPES which have to withstand pres- sure should have the fittings " sweated" on, the unions being screwed into place on the brass or copper pipe while the solder is still in a liquid state. CYLINDERS made of two or more parts require the joints of internal sleeve to be made with great care. 58 OIL ENGINES. Asbestos or a copper ring is used to make this joint; sometimes wire gauze with asbestos is used, which has been found to give very good results. CYLINDER LUBRICATORS. The lubrication of the pis- ton in explosive engines is of great importance. On those engines where it is convenient to use it, a mechanical type of lubricator is added. This device consists of an oil reservoir into which a wire attached to a revolving spindle is periodically dipped, the wire being also arranged to wipe over a projection which conducts the oil to a receptacle placed above the reser- voir and connected to the top of the cylinder. FIG. 310. The most efficient and economical lubricator for the piston is the force feed system shown in Fig. 310, where the lubricant is forced by pump and reaches the piston at the proper time and position for best results in lubrication. [Tables giving the Calorific Values of Oils, etc., will be found at end of Book.] CHAPTER III. TESTING ENGINES. THE chief object in testing explosive engines at the factory is to ascertain that, in actual working at dif- ferent loads, the several adjustments are correct. In the steam engine a physical process is completed, re- quiring only the inlet, expansion, and the outlet of the steam to and from the cylinder, whereas in the oil engine a chemical process is gone through consisting of the introduction of the proper mixture of vaporized oil and air into the cylinder, the ignition of this ex- plosive mixture and the consequent combustion. All this must be accomplished before the piston receives an impulse. In order, therefore, that the best results be obtained, the different mechanisms controlling these processes are each set, and record of their performance during the test is taken with the indicator, which results are again verified by some form of brake attached to the fly-wheels or pulley of the engine, and are further checked in an oil engine by the, record of the amount of oil which is consumed for the power developed. Where more detailed tests are required, the tempera- ture of the exhaust gases, the amount of air consumed in the cylinder, its temperature and barometrical pres- 6o OIL ENGINES. sure, together with the amount of cooling water neces- sary to keep the cylinder to the required temperature, are each noted and recorded. When the test is made with a new engine, it should be first started up and run without anv load for a short time. The cams are set as FIG. 32. shown in diagram, Fig. 32, for engines having both ail and exhaust valves actuated from the crank-shaft. The air-valve closes, as shown, just after the crank-pin has passed the out centre, the exhaust-valve opening at about 85 per cent, of the full stroke and closing just TESTING ENGINES. 6l after the air-valve has opened. Where the air-inlet valve is automatic the exhaust-cam only is set, as shown in the diagram, and the air-valve spring should be adjusted so that the incoming air is not choked in passing the valve during the suction stroke. The oil-pipes leading to the vaporizer or sprayer should be well washed before starting the engine, as with a new engine grit and filings may get into the pipes, and when the engine is started the oil-valves and valve-seats may be damaged. The oil-filter also must be in proper shape and clean, so that the oil can flow freely to the oil-pipe. After the vaporizer and igniter has been well heated a little oil should be allowed to enter the vapor- izer or combustion chamber; then the fly-wheels can be turned forward a few times, after which the engine should start freely. The method of starting the differ- ent types of engines is explained in detail in Chap- ter VII. An engine is sometimes found difficult to start the first time owing to some defect in the castings or workmanship, and if it fails to start, the engine should be examined in detail to ascertain the cause. First test the oil-inlet or spraying device by hand ; then test the pressure of compression in the cylinder by turning the fly-wheels backward. The relief-cam being out of action, it should not be possible with full compression to turn the fly-wheel past the back centre. If the compression is so slight that the pressure in the cylinder can be overcome and the fly-wheel turned during the compression period by hand, then either the piston-rings are leaking or there is leakage past TESTING ENGINES. 63 the air and exhaust valves or through some of the joints or gaskets. Air and exhaust valves and piston- rings should be examined, and any appearance of leak- age remedied by refitting the piston-rings, as already explained in Chapter II., and the valves, if necessary, should be reground in. New engines also fail to start at times by reason of the leakage of water from the cooling jacket into the cylinder owing to faulty gas- kets or flaws in the castings. This leakage of water may sometimes be ascertained by failure to obtain an explosion in the combustion chamber when all condi- tions in the cylinder and vaporizer are apparently in good order for the engine to start properly. If leakage of water is suspected but cannot be detected in this way, the water-pressure pump should be attached and the water-jackets tested to a pressure of 120 Ibs. The crank-shaft and other bearings require careful oiling at first, and full lubrication should be given to the piston ; otherwise it may, perhaps, work dry and cut the cylinder. After working a few hours, the piston should be withdrawn and examined ; any hard places on the sides should be eased either by careful hand filing or other- wise. The junk-rings (or distance-pieces between the rings) should be eased if necessary, so that they do not work hard on the cylinder. The full bearing of the piston should be from about -J" from rings forward to within |" of the front end, as already explained in Chapter II. The terms " brake," or " developed," or " actual" or " effective" H. P., are synonymous, and are used 64 OIL ENGINES. to signify the power which an engine is capable of delivering at the fly-wheel or belt-pulley. This power is variously designated, and here we shall use the ab- breviation B. H. P. to express it. The indicated H. P. represents the whole power developed by combustion in the cylinder, but it is not considered such a reliable method of measuring the power of explosive engines as that of the dynamometer or brake, because the in- dicator-card only gives the power developed by one or more explosions, whereas the brake can be applied for any length of time and shows the average performance of the engine for a longer period of time. Fig. 33 illustrates the engine as arranged for testing in the factory. The fuel tank shown at the left hand is placed there for the purpose of running the oil-con- sumption test. The fuel pump is connected tempo- rarily to this tank instead of taking its supply of oil from the tank in the base of the engine. The indicator is also shown in place on the top of the cylinder. The device for reducing the stroke of the crank to suitable dimensions for the indicator is also shown in place bolted to the bed-plate of the engine. The brake con- sists of rope " thick, with wooden guides with bal- ances at each extremity. The upper balance is sus- pended by adjustable hook suitably arranged for alter- ing the load on the brake. Various kinds of dynamometer brakes are used for testing; that shown in Fig. 33 is considered by the writer as being satisfactory. The brake should be attached as shown in the illustration, the load being taken as the number of pounds shown ori the upper FIG. 33&. (To face page 65.) FIG. 34- TESTING ENGINES. 65 scale less those shown on the lower scale. Brake or actual H. P. is calculated thus : 33,000 W= net load in pounds. C = circumference of wheel. N = number of revolutions per minute. The circumference of the wheel should be measured at the centre of the rope, thus allowing for half the rope thickness. The Prony brake being water cooled is recommended for larger engines. The power developed with this brake as shown in Fig. 33& is ascertained as follows : zRx-nX / X Qxn. Jt>. Jtl. Jr. = -^ ^ ^ - ^ 33.000 When R = radius of wheel in feet. Q = weight in pounds on scale -f- weight of brake apparatus. / = distance in feet from center of shaft to point of contact of lever with scale. TT = 3.1416. = R. P. M. The Alden dynamometer or absorption brake shown at Fig. 330 is advantageously used for measuring the horse-power when the prony brake or rope brake can- not be used. The power developed is calculated in the same way as with the prony brake, Fig. 33??. The dy- namometer can be operated by belt or direct connected to the shaft of the engine. 66 OIL ENGINES. THE INDICATOR is attached to the cylinder by first screwing into the cylinder the indicator cock, as shown at Fig. 340, to which the indicator is applied in the ordinary way. The length of the stroke of the engine must be re- duced to suit the dimensions of the diagram, which is FIG. 340. usually about 3" long. This is accomplished by the use of a device, as shown in Fig. 35 or 35^. Indicated H. P. is calculated thus : PLAE I.H.P.= . 33,000 P = mean effective pressure in Ibs. L = length of stroke in feet. A = area in inches of piston. E = number of explosions per minute. TESTING ENGINES. 67 The M. E. P. of indicator-card is obtained by the use of the planimeter, as shown in Fig. 37, or by meas- uring the card by scale and taking the average pres- sure. The illustration (Fig. 36) shows the design and FIG. 35. arrangement of the pajts of the Crosby gas-engine in- dicator. The cylinder proper is that in which the movement of the piston takes place. The piston is formed from a solid piece of tool steel, and is hardened to prevent any reduction of its area by wearing. Shal- 68 OIL low channels in its outer surface provide an air pack- ing, and the moisture and oil which they retain act as lubricants, and prevent undue leakage by the piston. 1 The piston is threaded inside to receive the lower end of the piston-rod and has a longitudinal slot which permits the bottom part of the spring with TESTING ENGINES. 69 its bead to drop on to a concave bearing in the upper end of the piston-screw, which is closely threaded into the lower part of the socket : the head of this screw is hexagonal, and may be turned with a hollow wrench. The swivel-head is threaded on its lower half to screw into the piston-rod more or less according to the required height of the atmospheric line on the diagram. Its head is pivoted to the piston-rod link of the pencil mechanism. The pencil mechanism is designed to eliminate as far as possible the effect of momentum, which is especially troublesome in high-speed work. The movement of the spring throughout its range bears a constant ratio to the force applied, and the amount of this movement is multiplied six times at the pencil point. SPRINGS. In order to obtain a correct diagram, the height of the pencil of the indicator must exactly represent in pounds per square inch the pressure on the piston of the oil engine at every point of the stroke ; and the velocity of the surface of the drum must bear at every instant a constant ratio to the velocity of the engine piston. THE PISTON SPRING is made of a single piece of spring steel wire, wound from the middle into a double coil, the spiral ends of which are screwed into a brass head having four radial wings to hold them securely in place; 80 to 200 Ib. spring is a suitable pressure for this work. This type of indicator is ordinarily made with a drum one and one half inches in diameter, this being 70 OIL ENGINES. the correct size for high-speed work, and answering equally well for low speeds. To remove the piston and spring, unscrew the cap; then take hold of the sleeve and lift all the connected parts free from the cylinder. This gives access to all the parts to clean and oil them. To change the location of the atmospheric line of the diagram. First, unscrew the cap and lift the sleeve, with its connections, from the cylinder; then turn the piston and connected parts toward the left, and the pencil point will be raised, or to the right and it will he lowered. One complete revolution of the piston will raise or lower the pencil point \" ', and this should be the guide for whatever amount of elevation or depression of the atmospheric line is needed. To change to a left-hand instrument. If it is desired to make this change : First, remove the drum, and then with the hollow wrench remove the hexagonal stop screw in the drum base, and screw it into the vacant hole marked L ; next, reverse the position of the adjust- ing handle in the arm ; also, the position of the metallic point in the pencil lever; then replace the drum, and the change from right to left will be completed. The tension on the drum spring may be increased or diminished according to the speed of the engine on which the instrument is to be used, as follows : Re- move the drum by a straight upward pull ; then raise the head of the spring above the square part of the spindle, and turn it to the right for more or to the left for less tension, as required ; then replace the head on the spindle. TESTING ENGINES. Jl Before attaching the indicator to an engine, allow air to blow freely through pipes and cock to remove any particles of dust or grit-that may have lodged in them. The indicator should be attached close to the cylin- der whenever practicable, especially on high-speed en- gines. If pipes must be used they should not be smaller than half an inch in diameter, and as short and direct as possible. The indicator can be used in a horizontal position, but it is more convenient to take diagrams when it is in a vertical position, and this can generally be ^ob- tained, when attaching to a vertical engine, by using a short pipe with a quarter upward bend. The motion of the paper drum may be derived from any part of the engine, which has a movement coinci- dent with that of the piston. In general practice and in a large majority of cases the piston itself is chosen as being the most reliable and convenient. When the indicator is in position and the cord-drum or other reducing motion is correctly placed, it is next necessary to adjust the length of the cord, so that the drum will clear the stops at each extreme of its rota- tion. The engine should be allowed to run for a few minutes to heat up before taking a diagram. The at- mospheric line should be drawn by hand, preferably after the diagram has been taken and when the instru- ment is heated up; the card is then taken with full- rated load on the brake. It is well to allow the pencil to go several times over the paper so as to procure a card showing several explosions, and thus the aver- age pressure can be taken. OIL ENGINES. The pressure of the pencil on the paper can be ad- justed by screwing the handle in or out, so that when it strikes the stop there will be just enough pressure on the pencil to give a distinct fine line. The line should FIG. 37- not be heavy, as the friction necessary to draw such a line is sufficient to cause errors in the diagram. THE PLANIMETER or averaging instrument is shown at Fig. 37. No. i planimeter is the simplest form of the instrument, having but one wheel, and is designed to measure areas in square inches and decimals of a TESTING ENGINES. 73 square inch. The figures on the roller wheei D repre- sent units, the graduations tenths, and the vernier E gives the hundredth*. F is the tracer and P is the pivot Fig. 37 represents the Xo. 2 planimeter, which is the same as the No. I, with the addition of a counting disc G, the figures on which represent tens and mark complete revolutions of the roller-wheel. By this means areas greater than ten square inches can be measured with facility. The result is given in square inches and decimals, and the reading from the roller wheel and vernier is the same as with Xo. i. Fig. 37 represents the Xo. 3 planimeter, which dif- fers somewhat in design from the two previously de- scribed. It is capable of measuring larger areas, and by means of the adjustable arm A giving the results in various denominations of value, such as square deci- meters, square feet and square inches; also of giving the average height of an indicator diagram in fortieths of an inch, which makes it a very useful instrument in connection with indicator work. DIRECTIONS FOR MEASURING AN INDICATOR DIAGRAM WITH A XO. I OR XO. 2 PLANIMETER. Care should be taken to have a flat, even, unglazed surface for the roller wheel to travel upon. A sheet of dull-finished cardboard serves the purpose very well. Set the weight in position on the pivot end of the bar P, and after placing the instrument and the diagram 74 OIL ENGINES. in about the position shown in Fig. 370, press down the needle point so that it will hold its place, set the tracer ; then at any given point in the outline of the diagram, as at F, adjust the roller wheel to zero. Now fol- low the outline of the diagram carefully with the tracer FIG. 370. point, moving it in the direction indicated by the arrow, or that of the hands of a watch, until it returns to the point of beginning. The result may then be read as follows : Suppose we find that the largest figure on the roller wheel D that has passed by zero on the ver- nier to be 2 (units) and the number of graduations that have also passed zero on the vernier to be 4 TESTING ENGINES. 75 (tenths), and the number of graduation on the vernier which exactly coincides with the graduation on the wheel to be 8 (htmdredths), then we have 2l|8 square inches as the area of the diagram. Divide this by the length of the diagram, which we will call 3 inches, and we have .8266 inch as the average height of the dia- gram. Multiply this by the scale of the spring used in taking the diagram, which in this case is 40, and we have 33.06 pounds as the mean effective pressure per square inch on the piston of the engine. DIRECTIONS FOR USING THE No. 3 PLANI METER. No. 3 planimeter is somewhat differently manipu- lated, although the same general principle obtains. The figures on the wheels may represent different quantities and values, according to the particular ad- justment of the sliding arm A. If it is desired merely to find the area in square inches of an indicator dia- gram, set the sliding arm so that the lo-square-inch mark will exactly coincide with the vertical mark on the inner end of the sleeve H at K. The sliding arm is released or made fast by means of the set-screw 5". With the wheels at zero and the planimeter and dia- gram in the proper position, trace the outline carefully and read the result from the roller wheel and vernier, the same as directed for the No. I and No. 2 instru- ments. THE INDICATOR-CARD shows what is occurring inside the cylinder and combustion chamber during the differ- ent periods of the revolution. It gives a record of the OIL ENGINES. variations in pressure, and also the exact points of the opening and closing of the valves. With the Otto or Beau de Rochas cycle the four strokes are as follows : Suction (A), compression (B), expansion (C), ex- haust (D). The lines in the diagram are correspond- ingly lettered (see Fig. 38), and they represent each of these processes. FIG. 38. Fig. 39 shows a good working diagram, in which the mixture of air and hydrocarbon gas is correct and where combustion is practically complete. The igni- tion line in this diagram is nearly perpendicular to the atmospheric line, but inclines slightly toward the right hand at top. The diagram also shows the open- ing of the exhaust-valve at the proper time namely, at 85 per cent, of the stroke. The compression line represents the proper pressure, and the air-inlet and exhaust lines indicate correct proportioned valves and inlet and outlet passages. I .'I TESTING ENGINES. 77 In considering and analyzing diagrams the follow- ing hints will perhaps be of service. If the suction line of the diagram is shown below the atmospheric FIG. 39- FIG. 40. line, as in Fig. 40, then the air-inlet to the cylinder is known to be in some way choked. Where the air-valve is automatic this defect may be caused by the valve- 78 OIL ENGINES. spring being too strong and it accordingly requires weakening ; or the area of the air suction-pipe, if this is used, may be too small or this connection may have too many elbows or bends in it, and should be either of in- creased diameter or the bends should be eliminated. Again, the valve itself may have too small an area, or if actuated have insufficient lift (the proper lift of a valve is of its diameter), or the period of opening of the valve may not be correct, and the setting of the cams should be carefully examined, and, if necessary, altered in accordance with the diagram of valve open- ing, as shown at Fig. 32. If the compression line B shows insufficient pres- sure of compression, this indicates leakage, which is probably due either to leaky piston or valves. If this leakage is past the piston-rings, the escaping air may be heard and the lubricating oil will be seen at each ex- plosion period to be splashing and blown past the rings of the piston. If no signs of piston leakage are noticed, then examine oil-inlet air and exhaust valves and valve- seats very carefully; also-note the various joints in the valve-box and otherwise where leakage might possibly occur. In engines without water-jackets around the valve-box the heat of the exhaust gases continually passing through the valve-chamber may sometimes cause the valve-seats to expand unequally when heated, and consequent leakage will occur when working. If leakage is detected at the valves they must be re- ground, and also any hard places on the valve-stems or guides where they become heated should be eased so that the valves will work easily and efficiently when the TESTING ENGINES. 79 seats and guides are expanded, and, perhaps, slightly distorted, by the heat of working. (It is understood that these remarks refer to new engines solely.) With some engines means of increasing the compression by movable plates on the connecting-rod crank-pin end or other somewhat similar means are provided which can be changed, if necessary, thus decreasing the FIG. 41. amount of clearance in the cylinder. If the piston- rings are without leakage and they have worked into their proper bearings in the cylinder, and if all the valves are in perfect order and without leakage, and still the compression pressure, as shown on the diagram and as already explained, requires increasing, then the clearance in the cylinder can be slightly decreased where it is possible to do so. The vertical ignition line shows the timing of the ignition, and also the initial pressure of explosion. If this line is as represented in Fig. 41 the ignition is known to be too early, and should be arranged to occur somewhat later. The 8o OIL ENGINES. diagrams as shown in Fig. 42 has the ignition line too late. The timing of the ignition is regulated as follows : With electric ignition by altering the period of FIG. 42. sparking. Thus, if later ignition is required the ignit- ing device must not be allowed to spark till the crank- pin has travelled nearer to the dead centre. With the hot-tube ignition and no timing valve, the length of the r TESTING ENGINES. 8l tube can be changed. For example, to retard the ignition the tube should be lengthened slightly and its temperature somewhat decreased. In engines where neither of these means of ignition is used, but where the ignition is caused by the heat of the vaporizer- chamber or somewhat similar device, the timing of the ignition is controlled by the heat of the vaporizer- chamber and also by the heat generated by the process of compression. Where the ignition in this case is to be retarded, the compression should be reduced slightly and the vaporizer or other igniting device maintained at a less heat. The ignition, however actually caused, is always influenced by the heat of the cylinder walls and the temperature of the incoming air, which corre- spondingly increases or decreases the heat caused by the compression before explosion takes place. The ignition is usually adjusted when testing engines with the cooling water issuing from the cylinder water- jackets at a temperature of 110 to 130 Fahr. The expansion line is marked C, as shown in Fig. 38. This line indicates the initial pressure of combustion, and it also shows the developed pressure decreasing as the volume of the cylinder becomes greater with the piston moving forward. The effective pressure devel- oped is measured from this line to the compression line, and varies according to the richness of the ex- plosive mixture. When the engine is in actual use - the governor controls this pressure automatically. The mean effective pressure is greater in some types of engines than it is in others, and varies, as stated in Chapter II., from 40 to_ 75 Ibs. The amount of the 82 OIL ENGINES. pressure in the cylinder is dependent upon the method of vaporization, upon the proper mixture of the gas FIG. 43. and air before explosion, and also upon the pressure of the compression. As in gas engines, the tendency in oil-engine practice is toward higher compression to TESTING ENGINES. 83 increase their efficiency. Where the mean effective pressure is low the relative power of the engine will, of course, also be reduced. The greatest mean effective pressure should be attained when the oil is thoroughly vaporized, is properly mixed with the air and when the compression is as high as practicable without pre- ignition taking place. Should the exhaust lines D appear as in Fig. 43, then it is understood that the discharge of the exhaust gases is in some way choked ; this may be caused by the ex- haust-valve itself being too small, or to the periods of the opening of the valve being incorrect. (See dia- gram, Fig. 32.) Again, this defect may be caused by too many sharp bends, too small diameter exhaust- pipe, or possibly too long an exhaust-pipe. Theoreti- cally no back pressure should be allowed during the exhaust period, but usually in practice a slight pres- sure of about one pound is recorded. Each pound per square inch of back pressure shown by the exhaust line shows a back pressure in the cylin- der, which is negative work to be overcome by the piston, and represents a slight loss of power by the engine. Care must be taken that the indicator is in proper condition, without any play in the pencil arm, and that the piston is free and well lubricated. Lost motion in the indicator may show peculiarities in the diagram which to an inexperienced manipulator may be the cause of trouble. TACHOMETERS (Fig. 44). These instruments have been designed for the purpose of ascertaining at a 8 4 OIL ENGINES. glance the number of revolutions made in a given time by rotating shafts. Their construction is based on centrifugal power, and they consist of a case inside of which are mounted a pendulum ring, in connection with a fixed shaft, a sliding rod and an indicating FIG. 44. movement. The apparatus is very sensitive, and will indicate the slightest deviation in speed. PORTABLE TACHOMETER (Fig. 440). This instru- ment is similar in construction to the tachometer for permanent attachment. By applying it by hand to the centre of rotating shafts, it will instantly and correctly indicate the number of revolutions of the shaft per minute. Fig. 44& illustrates a new form of speed counter, the TESTING ENGINES. 85 invention of Mr. A. J. Hill, of Detroit, Mich., which, besides counting, also registers the number of revolu- FIG. 440. tions of the shaft. This is accomplished by simply punching a continuous slip of paper, as shown in Fig. 44C. The watch mechanism in the device also periodically records a detent in the paper slip, thus marking the periods of time while the shaft actuates the mechanism of the device, causing a detent for each 86 OIL ENGINES. revolution. The writer has not yet had an opportunity of testing this interesting and useful invention. When the full brake H. P. is obtained, which should be developed for at least a period of one hour con- tinuously, the consumption fuel test is made. THE MECHANICAL EFFICIENCY of oil engines, as shown by records of various tests, should be from 80 per cent, to 88 per cent., although the efficiency is much less than this when the engine has been working only a short time and before the crank-shaft and other bearings and piston are worn in. To ascertain the mechanical efficiency of an engine, first calculate the I. H. P., as already described ; then figure the B. H. P., as already shown. Then: B. H. P. Mechanical efficiency = I. H. P. For instance : If the B. H. P. of an engine = 10 and the I. H. P. = 12.5, 10 Mechanical efficiency = 12-5 = So per cent. THERMAL EFFICIENCY. The ratio of the heat util- ized by the engine, as shown by the power (B. H. P.) developed, as compared with the total heat contained in the fuel absorbed by the engine, is known as the thermal efficiency. This can be obtained by the follow- ing formula: 42.63 X 60 cxx TESTING ENGINES. 87 C = consumption of fuel in pounds per B. H. P. per hour. X = calorific value of the fuel per pound in heat units. The thermal efficiency of different makes of oil en- gines varies. In the older type of engines a thermal efficiency of 15 per cent, was the maximum, as shown by the following disposition of heat by Mr. Dugeld Clerk, applicable to older engines. In the modern en- gines (see test, page 248) a thermal efficiency equiva- lent to approximately 28 per cent, has been obtained. Heat shown on diagrams per I. H. P. . 15.3 per cent. Heat rejected in water-jackets 26.8 per cent. Heat rejected in exhaust and other losses 57.9 per cent. 100 per cent. The above table of disposition of heat is applicable to smaller engines. The efficiency of the gas engine is approximately 27 per cent, while the efficiency of the complete steam plant does not exceed 12 per cent. FUEL CONSUMPTION TEST. This is generally made with all new engines before they leave the factory, and is advantageous as a check of the efficiency of the engine as shown by the indicator and the brake tests, and this test is also useful to ascertain the exact con- sumption of fuel by the engine in actual operation. 88 OIL ENGINES. The oil is weighed, the amount being gauged by weight of fuel rather than by measuring the oil. The tank or other receptacle from which the fuel is drawn is first filled with kerosene. The tank is then placed on platform scales, and the weight is carefully taken and time noted when the engine is ready to begin this test. The full load required is then adjusted on the brake while the engine is running at its normal speed. The oil can also be measured by means of a pointer placed in the tank, the tank being filled until the pointer is just visible before the engine is ready for the test to commence. The oil is then weighed in a separate vessel, and a quantity of the fuel is poured into the test tank. When the test is completed, the oil is taken out of the tank until the pointer shows again just as it did at the commencement of the test. The weight of the kerosene remaining in the vessel is deducted from the whole weight as at first recorded, and the difference is the amount consumed by the engine. It is usual to continue this test for at least one hour's duration. Dur- ing the consumption test, the load on the brake and the number of revolutions per minute are recorded and the average brake horse-power developed is taken. The exact amount of oil consumed per hour being also known, the consumption of oil per H. P. hour is simply ascertained. Light spring indicator diagrams are taken to ascer- tain the efficiency of the air and exhaust valves, ports and passages. That shown at Fig. 45 is taken with -fa spring. The indicator must be fitted with special stop arrangement to prevent the pencil going above TESTING ENGINES. 89 the drum of the indicator when taking light spring cards. It is advantageous to have some method of limiting the supply of oil to the vaporizer arranged so as to pre- vent the engine from consuming an excess of oil at any time. This gauge should be made immediately after the consumption test has been proved as satisfactory, and to avoid possible mistake by alteration of the oil supply. As already described, if too much oil enters SUCTION FIG. 45- the vaporizer, bad combustion will follow and carboni- zation will, perhaps, result, thus rendering the piston sticky and gummy, and materially reducing the effi- ciency of the engine. The exact periods for the movements of the valve and cams should also be clearly marked on the gearing or elsewhere, so that if at any future time the crank- shaft is taken out or the gearing (or other mechanism) between the crank-shaft and the cam-shaft removed, 90 OIL ENGINES. the relative position of the crank-shaft with the valve mechanism can be readily ascertained and the exact position of the cams again found without difficulty. EXHAUST GASES. With an oil engine it is impor- tant to note the color of the exhaust gases, which may vary a little according to the weather. Where com- plete combustion is taking place, the exhaust gases arc almost, if not entirely, invisible. When the engine is first started, these gases will, perhaps, be white, grad- ually getting bluer. If an oil engine is working well and if the combus- tion is complete, the exhaust gases will not be seen but only heard, and the piston will also remain clean in working. TESTING THE FLASH POINT OF KEROSENE. Fig. 460 shows apparatus for ascertaining the " open fire" test or the temperature at which kerosene will flash or ex- plode. This device consists of a small copper vessel in which the kerosene is placed. This vessel is immersed in a larger vessel containing water, which forms part of the upper part of the apparatus. A thermometer is suspended with its lower part in the oil. A heating lamp placed under the receptacle containing the water raises the temperature of both water and oil as required. A lighted taper is passed to and fro over the top of the oil as it becomes heated. When the vapor given off by the oil flashes the tem- perature is noted, and that is termed the " flashing point" of the oil thus tested. The " Abel" oil-tester is shown at Fig. 46^. This TESTING ENGINES. was originated by Sir Frederick Abel, and hence its name. The tests made with this apparatus are those known as the " Abel closed" test. Such tests are recog- nized by the law (at the present time) of Great Britain. FIG. 46. The device consists of a copper vessel containing water in which is an air-chamber. In the air-chamber is placed an oil-cup made of gun-metal. This oil-cup is supplied with tight-fitting lid, and is provided with gas 92 OIL ENGINES. or oil lamp suitably arranged to ignite the oil vapor when required. Two thermometers are required, one immersed in the oil and the other in the water, each having a tight joint around it. The following' are the instructions for performing this test: The heating vessel or water-bath is filled until the water flows out at the spout of the vessel. The temperature of the water at the commencement of the test is 130 Fahrenheit. The water having been raised to the proper temperature, the oil to be tested is poured into the petroleum cup, until the level of the liquid just reaches the point of the gauge which is fixed in the cup. If necessary, the samples to be tested should be cooled down to about 60. The lid of the cup with the slide closed is then put on, and the oil-cup is placed in the water-bath or heating vessel, the thermometer in the lid of the cup being adjusted so as to have its bulb immersed in the liquid. The test-lamp is then placed in position upon the lid of the cup, the lead line, or pendulum, which has been fixed in a convenient posi- tion in front of the operator, is set in motion, and the rise of the thermometer in the petroleum cup is watched. When the temperature has reached about 66 the operation of testing is to be commenced, the test flame being applied at once for every rise of i in the following manner : The slide is slowly drawn open while the pendulum performs three oscillations, and is closed during the fourth oscillation. Thus a flame is made to come in contact with the vapor above the oil. Thfe temperature TESTING ENGINES. 93 at which the vapor flashes is noted, and is called the flashing point of the oil. If it is desired to employ the test apparatus to determine the flashing points of oils of very low volatility, the mode of proceeding is modi- fied as follows : The air-chamber which surrounds the cup is filled with cold water, to a depth of i^ inches, and the heat- ing vessel or water-bath is filled with cold water. The lamp is then placed under the apparatus and kept there during the entire operation. If a very heavy oil is be- ing dealt with, the operation commences with water previously heated to 120 instead of with cold water. VISCOSITY OF OIL. It is frequently advantageous to ascertain the viscosity of different oils. The device shown at Fig. 46^ is manufactured by C. I. Tagliabue especially for this purpose. The viscosity of an oil with this apparatus is found by noticing the number of seconds required for fifty cubic centimetres of oil to pass the open faucet or valve. To test the viscosity of oil at 212 Fahr. with this apparatus, first pour water into the boiler through opening A, unscrew safety-valve until water-gauge shows that the boiler is full, open stop-cock B, making a direct connection between the boiler and upper vessel which surrounds the receptacle in which the oil to be tested is placed. Suspend a thermometer so that its bulb will be about inch from the bottom of the oil-bath. After carefully straining 70 cubic centimetres of the oil to be tested, which must be warmed in the case of very heavy oils, pour same into the oil-bath. Close 94 OIL ENGINES. stop-cocks D and . Screw the extension F with rubber hose attached into the coupling G, and let the open end of the hose be immersed in a vessel of water, FIG. 46c. which will prevent too large a loss of steam. Place lamp or Bunsen burner under boiler ; screw steel nipple marked 212 on to stop-cock H ; the apparatus is then ready to use. After steam is generated, wait until the TESTING ENGINES. 95 thermometer in oil-bath shows a temperature of from 209 to 211 ; then place the 50 cubic centimetre glass under stop-cock H, so that the stream of oil strikes the side of test-glass, thereby preventing the forming of air-bubbles ; and when the thermometer indicates its highest point open the faucet H simultaneously with the starting of the timing watch. When the running oil reaches the 50 cubic centimetre mark in the neck of the test-glass the watch is instantly stopped and the number of seconds noted. To ascertain the viscosity, multiply the number of seconds by two, and the result will be the viscosity of the oil. For example : If 50 cubic centimetres of oil runs through in loif seconds, the viscosity will then be 203. To test the viscosity of oils at 70 Fahr. screw the steel nipple marked 70 on to faucet H ; close stop- cock B, closing communication between boiler and upper vessel ; also close stop-cock E. Fill upper vessel through opening G with water at a temperature as near 70 as possible, also having the oil to be tested at the same temperature ; hang the thermometer in position, and after stirring the oil thoroughly, blow through rub- ber tube at D to thoroughly mix the water ; should the thermometer show higher or lower than 70 add cold or warm water until the desired temperature is at- tained. Then proceed as before stated. [For tables of tests of various oil engines, see end of book.] CHAPTER IV. COOLING WATER-TANKS, AND OTHER DETAILS. WATER is always required to keep the cylinders of explosive engines cool, and is necessitated by the great heat evolved in such engines, which heat would, if it were not carried away, prevent the proper working of an engine by too great expansion of the piston and by burning the lubricating oil. Where running water is not available, water-tanks are sometimes used. The engine water-jackets are connected to the tanks as shown in Fig. 47. It is important that the water piping rises all the way from the engine to the tanks. The water, when tanks are used, circulates by gravi- tation that is, the cold water being slightly heavier than the hot sinks to the bottom of the tank, passes from the tank to the water-jacket, and returns as warm water to the top of the tank to be cooled off and again sink to the bottom of the tank. The cooling water-tanks must be of not less capac- ity than 70 gallons of water per brake H. P. of engine. The tanks when installed should preferably be placed in the best location for cold air to circulate around COOLING WATER-TANKS AND OTHER DETAILS. 97 them, so that the water in the tanks may cool off as quickly as possible. Where an engine is required to work for more than ten hours per day, the tanks should be of larger capac- ity than that above stated, or provision should be made FIG. 47. to add cold water to the tanks when the water becomes heated above 120 Fahrenheit. The waste-water drain-pipe from the tanks should be arranged to allow the hot water to run off from the top of the tanks and the cold-water inlet-pipe arranged to enter near the bottom. The circulating-water pipes connecting the tanks to engine water-jacket should be large enough to allow the water to circulate freely. A pipe having i" inside diameter is considered suit- 98 OIL ENGINES. able for the smaller size of engines and 3" diameter pipe is sufficient for engines of 25 B. H. P. and ovei*. In some installations cooling water is available, but may require pumping to the engine. In such cases a pump capable of delivering more than ten gallons per brake H. P. of engine should be used. This pump can be actuated from the cam-shaft of engine as shown in Fig. 50, or from the crank-shaft by eccentric in the usual way. A rotary pump is sometimes used to ac- celerate the circulation of water in hot climates with the tank system of cooling water, and can be driven by belting from the crank-shaft of the engine. A by-pass in the water-pipes between the suction-pipe and the discharge-pipe of the water-circulating pump is advan- tageous, having a regulating valve in the by-pass. If this by-pass is not made, other means should be ar- ranged, so that the supply of cooling water can be regu- lated to maintain the proper temperature of the cylin- der of the engine namely, 110 to 130 Fahrenheit. This temperature is recommended by the makers of several oil engines. Where neither pump to' lift and circulate cooling water nor water-tanks are necessary and where water is used from the city water-mains, f " inside diameter pipe is sufficient for small and moderate-sized engines. The larger size may have i' f diameter pipe connections to cylinder. In all cases, either with tanks, water-pumps, or where the water is connected direct from the city water-main, provision must be made for emptying the cylinder water-jacket and all the water-pipes in time of COOLING TOWER ON THE TOP OF THE BUILDING (To face p. 98.) FIG. 48^. (To face p. 99-) COOLING WATER-TANKS AND OTHER DETAILS. 99 frost. If the water in the water-jacket of the cylinder should be allowed to freeze, the cylinder casting may be cracked, and this may necessitate very expensive repairs. RADIATORS FOR COOLING PURPOSES. This is an ap- paratus for cooling the cylinder water of engines, some- times used where space is not available for cooling tanks, and where the cooling tower shown in Fig. 48^ cannot be used, and where the supply of water is lim- ited. This device consists of a radiator through which the cooling water is forced as it issues from the engine. It is made up of a large number of small tubes having radiating flanges around them or of other suitable de- sign, affording a large cooling surface. A fan operated by electric motor is placed in front of the radiator, as shown in the illustration, and is arranged to furnish a strong current of air passing through the various coils of the radiator, taking up the heat of the water in the tubes and quickly cooling same. The power required by the motor is approximately 10% of the power devel- oped by the engine. A difference in temperature can be obtained between the inlet and outlet water when using this device of from 25 to 30 Fahr. About 40 gallons of water should be circulated through the coils per actual horse-power per hour. These figures, however, depend upon the design of the radiator and the conditions of temperature under which it is to operate. On account of the large amount of power absorbed by the motor, this outfit is only suitable for special in- stallations where other cooling methods cannot be used. TOO OIL ENGINES. COOLING TOWERS Where cooling tanks cannot be installed, for instance in large installations where enormous capacity of tanks would be required, a cooling tower as shown at Fig. 48 and Fig. 480 can be advantageously used. In this case, the heated water as it issues from the engine cylinder water-jacket is pumped to the top of the cooling tower, which is placed in a position to allow of the best cooling effect, the water simply flowing down the surfaces of the cooling tower, and its temperature being reduced by coming in contact with the air. Where large amounts of water have to be cooled, a fan is added to increase the draught of air coming in contact with the water to be cooled. EXHAUST SILENCERS. The noise from the exhaust gases is sometimes considered to be a great objection to the use of explosive engines, but this is chiefly due to the fact that the ordinary cast-iron exhaust silenc- ing chamber supplied with engine is not designed to entirely silence the exhaust, but is only regarded as sufficient to partly reduce this noise. Where it is essential that the exhaust be entirely silenced, this can be easily accomplished in the follow- ing way : A brick pit should be built as shown in Fig. 49. The exhaust-pipe from the engine is then connected to the bottom of this pit. The outlet-pipe to the atmosphere is connected to the top of the pit. The space inside the pit should be filled with large stones, as shown in illustration. These stones should be about six inches in size, so that crevices are left COOLING WATER-TANKS AND OTHER DETAILS. IOI between them through which the gases can penetrate. A drain-pipe should be arranged to allow the water to flow out of the pit. The stone or cast-iron plate covering the pit is securely fastened down to the masonry.* With oil-engine exhaust gases there may be some odor. When it is necessary that both the noise and the odor should be done away with, an exhaust washer should be installed instead of the silencing pit, as -al- ready described. This apparatus consists of a tank, to which the water is connected as it issues from the water-jacket of the engine-cylinder, or where cooling *In some cases the connection is made direct from the engine to the silencer, and thence to the pit, the exhaust pipe leading to the atmosphere being supported from the cover- ing over the pit. 102 OIL ENGINES. COOLING WATER-TANKS AND OTHER DETAILS. IO3 tanks are used the water should be taken from the main. About 100 gallons of water are required per hour. The exhaust-pipe from the engine valve-box is also connected directly to this tank. The outlet of the water is connected from the tank to sewer and the out- let exhaust-pipe is also connected in the usual way to the top of the building. The exhaust gases by this arrangement come in contact with the water and are partly condensed and quite purified. The pressure and noise are eliminated entirely, any deposit of carbon left in the gases after combustion is carried off by the water to the sewer, and there is practically no odor when the gases escape from the exhaust-pipe to the atmosphere at the roof. This device is shown in Fig. 51. The sizes given for piping and tank are those suitable for a 10 to 20 H. P. oil engine. The internal piping in the tank is so placed to avoid any pressure which is created inside the tank due to the exhaust gases of the engine from entering the sewer. If any water is blown out at the top of the exhaust-pipe, a steam exhaust-head is used for obviat- ing this. This apparatus is the same as used on steam exhaust-pipes. Sizes for piping and tank for a 10 to 20 H. P. oil engine : Pipe from engine, 3" diameter. Pipe of water inlet, f " diameter. Pipe to atmosphere, 3" diameter. Pipe to water outlet, 2" diameter. Size of tank, 2' in diameter by 4' high. 104 OIL F.XG1XKS. When it is required to partly silence the noise of exhaust only part or all of the water from the cooling jacket can be turned into the exhaust-pipe directly from the water-jacket. The water is allowed to mn to waste again at the silencer. (See Fig. 52.) Wherever water is connected to the exhaust-pipe, care must be taken that none can under any condition enter through FIG. 52. the exhaust valve-box into the cylinder or vaporizer of the engine. Where water enters the silencer or the piping under pressure from the city main or otherwise. it is necessary that the area of the outlet-pipe be large enough to allow the water to drain freely at atmos- pheric pressure. If the water is not allowed free drainage, it may quickly fill up the silencer, and per- haps enter the valve-box of the engine, causing the engine to stop working. COOLING WATER-TANKS AND OTHER DETAILS. 1 05 SELF-STARTERS. Engines of 25 H. P. and over should be provided with separate means of starting besides the relief-cam for reducing the pressure of compression as usually provided with the smaller sizes of engines. The weight of the fly-wheels and recipro- cating parts on the larger engines which are to be put in motion when being started necessarily entails con- siderable exertion, and the strength of two men is re- quired to do this work where no other means is pro- vided for this purpose. There are several different self-starting devices made for gas engines, and it is much easier to accom- plish this work with a gas than with an oil engine, since with the former gas only has to be dealt with and can be readily diluted with air and an explosive mixture formed, whereas with the oil engine the fuel must be vaporized first and then mixed with the air before an explosive mixture is available to be ignited and the im- pulse on the piston obtained. In order, therefore, to accomplish these various operations necessary in the oil engine, sufficient power must be independently pro- vided to turn the engine crank-shaft over two or three revolutions so that the different mechanisms can work, the fuel be injected or inducted into the cylinder or va- porizer, become mixed with the incoming air and an explosion obtained, thus giving the required impulse. This power is usually derived from a separate air reser- voir charged during the previous running of the engine or from a small air-compressor operated by hand. The self-starter used with the Hornsby-Akroyd type io6 OIL ENGINES. of oil engine is shown in Fig. 53. The reservoir is con- nected to air and exhaust valve-box of engine through a supplementary valve-box containing two check- valves. These check- valves are arranged to be lifted from their seats by means of the hand-lever as shown. The following are the instructions in detail for start- ing these engines by means of this device. (These re- FIG. 53- marks are generally applicable to all types of engines provided with starting devices of this principle.) See that the valve A on the steel receiver is open, and also the cock B on the pipe leading from the hand air-pump. Put the starting lever in the quadrant at the position marked " Running and when charged," and pin it there. Then screw down the valve C on the double valve-box, and pump air into the receiver by the COOLING WATER-TANKS AM) OTHER DETAILS. IO/ air-pump up to a pressure of say 60 or 70 Ibs. to the square inch as shown on the gauge. Then close the cock B on the air-pump pipe, withdraw the pin in the starting lever, and put it in the hole by the side of the lever to act as a stop ; then place the engine ready for starting as elsewhere described. Place the crank a little over the dead centre in whichever direction the engine is intended to run, unscrew the valve C in double valve-box, and then suddenly push the starting lever forward to the end of the quadrant, and the en- gine will start. Pull the lever back immediately against the pin, and screw down the valves on the double valve-box and on the receiver. Before stop- ping the engine at any time, pull the lever back and pin it in hole marked " To charge ;" unscrew the valves on the double valve-box and receiver, and allow the engine to pump air into the receiver again to 80 or 100 Ibs. pressure ; put the lever to the centre hole marked " When running, and when charged," and pin it there ; screw down the valves on the receiver and valve-box, and the air pressure in the receiver will be retained in readiness to start the engine the next time it is re- quired. If an air-pump is not provided, the engine must be started' in the usual way the first time, by pull- ing round the fly-wheel, and the receiver afterward filled each time before stopping. THE UTILIZATION OF WASTE HEAT FROM OIL EN- GINES. With many installations of oil engines, the question of utilizing the waste heat from the water- jacket and exhaust gases is considered. The amount of heat lost in this way of course varies with different io8 OIL ENGINES. types of engines according to their thermal efficiency. Reference to the following table shows the amount of heat rejected in the cooling water and exhaust. The two greatest disadvantages to the utilization of waste heat are: First, the oil engine furnishes heat only when in operation, and therefore a separate heater is required to furnish the necessary heat when the en- gine is stopped ; and secondly, as the exhaust gases from most oil engines are not clean, accumulation of carbon results in the passages through which the heated gases pass and necessitates frequent cleaning. HEAT BALANCE PER ACTUAL OR B. H. P. PER HOUR. B. T. U. B T. U. Received by en- Heat equivalent gine 0.8 Ib of shown on brake fuel at !9, 000 (82$ mech. ef.) 3 ,104 B. T U. per Ib. Heat lost to jacket 19,000 X 0.8 Ib. water 47.4$ 7 ,200 = IS, 200 Heat lost to ex- haust 25$ 3 ,800 Lost in radiation and unaccount- ed for i Op6 , wy w 15,200 [5 ,2OO The above table is based on 0.8 Ib. fuel consump- tion per actual H. P. hour. With engines having a higher economy, the amount of heat rejected would be reduced. Assume the efficiency of the heating appa- COOLING WATER-TANKS AND OTHER DETAILS, log ratus to be 68%, then with the heat rejected by the water jacket, viz., 11,000 B. T. U., 7,480 B. T. TJ. should be available for heating purposes per actual H. P. per hour. An apparatus designed to utilize the waste heat from the exhaust is shown at Fig. 54. The heat could be utilized either by water circulation or by means of heated air, a blower being used to pass the cold air over the heated water pipes or by steam heat direct. With the first arrangement piping in which the water is circulated would have to be of sufficient length to allow the water to give out its heat. With the second arrangement (that of heated air) sufficient quantity of air should be passed over or through the piping in which the heated water flows. This heated air is then passed through ducts to the spaces to be heated in the ordinary way. The third system, namely, steam heat, would require the exhaust gases to raise the tempera- ture of the water above the boiling point, 212. Each pound of steam at 212 evaporated from water at 140 requires 1038 B.T.U. As previously stated, if the IIO OIL ENGINES. efficiency of the heating apparatus is as high as then there is available from the exhaust gases. 3800 X 0.68 = 2584 B.T.U. per B.H.P. per hour. This heat will be sufficient to raise about 2^2 Ibs. of water to 212 steam or somewhat less than this amount to steam at 15 Ibs. gauge pressure. It is estimated that 3.6 B.T.U. are required to maintain a cubic foot of space at 70 F. when the weather is at zero outside, and 2.6 B.T.U.'s are required to maintain the same tem- perature inside when the outside temperature is 20 F. These figures, of course, have to be varied with dif- ferent buildings. The above figures are also estimated with the engine running at full load. At half load only about 60% of the heat above referred to would be available. EXHAUST TEMPERATURE. The temperature of the exhaust gases is difficult to ascertain correctly. The temperature of the exhaust from the Diesel engine is recorded by Professor Denton as being approximately 740 Fahr. The temperature of different oil-engine exhaust gases varies, and it is probably considerably above that figure. This temperature varies also, of course, according to the size of the engine, and also according to the power that the engine is developing. The heat is greatest at full load and on the largest engines. CHAPTER V. OIL ENGINES. DRIVING DYNAMOS. OIL ENGINES for many reasons are well adapted for driving dynamos generating electric current in isolated lighting plants. A large number of such installations have been made in recent years. The oil engine is self- contained, and, unlike a gas engine, is independent of gas works or gas-producer plant for its supply of fuel. Small power installations with oil engines as prime movers should require also less attention than a plant equipped with steam engine and boilers. There is probably not the danger there is with a steam engine of explosion, and as the fuel used is ordinary kerosene of a safe flashing point, there can be little or no fear of destruction by fire. Practically, no hauling of fuel is required, nor is there, with an oil engine, any consump- tion of water if storage tanks are installed. Further, an oil engine does not deteriorate if only required for part of the year and left standing idle for the remainder of the time.' With these and, perhaps, other advan- tages possessed by oil engines, their adaptability for driving dynamos in isolated electric-lighting and power plants may be understood. Fig. 55 illustrates an oil OIL ENGINES DRIVING DYNAMOS. 113 engine driving dynamo with link belt. The dynamo is placed close to the engine to economize floor space. This plant is arranged with the cams having been set for the engine to run backwards. INSTALLATION. In order that the plant may be en- tirely satisfactory and give the best results, it is very essential that the engine and dynamo be correctly located with regard to each other and properly installed at the outset. THE FOUNDATIONS both for the engine and for the dynamo should be built of good cement concrete, and should be placed on solid ground, so that they are steady and without vibration. The engine foundation can be made as shown at Fig. 56. When, however, the ground that the foundation is built upon is not solid, it is preferred to build the foundation more tapered than shown toward the bottom, thus increasing the surface that the concrete rests on. The weight of the foundation is considered sufficient allowing about 5 cubic feet per I. H. P. for engines under 50 H. P. for concrete. For engines over 50 I. H. P. the foundation can be reduced per I. H. P. If the foundation is built of brickwork, its dimensions should be somewhat greater than those given for concrete. The ingredients of the best concrete are broken stone, Portland cement and sharp sand. The fuel tank placed underground surrounded with concrete and installed. in accordance with the requirements of the fire underwriters is shown at Fig. 560. The fuel supply pipe connections and fuel supply pump are also shown as required by their regulations. OIL ENGINES. IJ7HS-. XNVUO JO 'TO OIL ENGINES DRIVING DYNAMOS. 1 15 When driving by belt the distance between the cen- tres of the dynamo and the engine-shafts is an im- portant feature. Where space is restricted and it be- comes essential that the dynamo be placed as close as possible to the engine 1 , it is advantageous to use a link leather belt, allowed to run quite loose, the part of the belt in tension being underneath, the loose part being on top, so that the arc of contact made on the smaller pulley of the dynamo is as great as possible. This arrangement with loose belt lessens the friction on the bearings, which" would be occasioned if the belt were made tight, as required at short centres with ordinary leather belt. When using link leather belt, the distance between the centres should be with the usual standard size of fly-wheels 2 to 2.5 diameters of the engine fly- wheels that is, the distance should not be less than 7 ft. for wheels of 3' 6" diameter and not greater than 15 ft. for wheels of 6 ft. diameter. Where or- dinary leather belt is used instead of link belt, this dis- tance should be increased to 3 diameters of fly-wheel, but in any case this dimension should not exceed 18 ft. for driving wheels 6 ft. in diameter. To obtain absolutely steady light, it is sometimes advantageous to place a balance-wheel on the armature shaft of the dy- namo. This wheel if used should weigh about 15 Ibs. per K. W. of dynamo, and be of such diameter that at the maximum speed of dynamo its peripheral speed will not exceed 6000 ft. per minute. This wheel must be accurately balanced, and is usually cast in one piece with pulley, as .shown in Fig. 57. The OIL ENGINES. necessary width of belt to transmit the H. P. may be calculated as follows : H. P.=- 800 H. P. = the actual horse-power. V = velocity of belt in feet per minute. w = width of belt in inches. FIG. 57- The maximum number of incandescent lights avail- able from the dynamo per brake or actual H. P. of engine varies according to the efficiency of the dynamo, and the efficiency of the means of transmission as well as to the efficiency of the electrical installation. Lack of OIL ENGINES DRIVING DYNAMOS. I \J power as recorded by the electrical instruments is not necessarily due only to defects of the engine, as leak- age of power may occur in various ways, as above stated. Usually ten 16 candle-power lights per Brake H. P. are calculated as being a fair load for the engine. With arc lamps of 2000 candle-power, the B. H. P. of engine for each lamp required is approximately .75. It is advisable to have spare power with an. explosive engine above that required to run all the lights. Losses of power should be allowed for in the belt, which vary from 10 to 15 per cent. The regulation of explosive engines for electric lighting must necessarily be such that there is no flicker in the incandescent lights. A speed variation of 2 per cent, is now guaranteed with several oil engines. This regulation gives a very good light and equals that developed with many steam engines. When space is not available to permit the use of belt transmission, the dynamo is connected directly on to the shaft of the engine, as in Figs. 58 and 580. The coupling between engine-shaft and dynamo is usually flexible to allow of dynamo bearings and the engine- shaft bearings remaining in alignment when they be- come worn. In direct-connected plants the loss due to the belt transmission is avoided, and a saving is thus effected; but, on the other hand, the first cost of the dynamo is very much greater, running, as it does, at a slower speed than the belt-driven machine, and there- fore is of larger dimensions, and consequently more costly. Fig. 58 illustrates a Hornsby-Akroyd engine of the OIL ENGINES DRIVING DYNAMOS IIQ twin cylinder horizontal type coupled direct to the generator. The illustration shows the engines placed each side of the generator with two flywheels and con- nected by coupling forged on the shaft. An arrange- ment preferred is the two engines placed side by side with one heavy flywheel, the generator is coupled to the engine shaft and placed on one side. Where this outfit has been used for power purposes the timing of the air inlet and exhaust cams has been such that the explosions have been simultaneous in each cylinder. In this way the strain on the generator shaft has been reduced. Fig. 580 illustrates the Mietz & Weiss horizontal type of engine directly connected to dynamo through flexible coupling. This engine, being of the two-cycle type, receives an impulse at each revolution of the crank-shaft, and it runs very regularly and at a high rotative speed. The method of working of the Mietz & Weiss engine is fully described in Chapter IX. The fly-wheels of explosive engines intended for driving dynamos are usually made heavier than when the engines are required for other purposes. (See Chapter II.) Notwithstanding the special design of engines for electric-lighting purposes and apparent correct adjust- ment of the governing mechanism, the lights may sometimes be seen to flicker. Flickering in the incan- descent lights can be easily located by close inspection of the engine and dynamo, and may be due either to the fly-wheels, the governor, the belt, or the dynamo itself. To precisely locate this defect and remedy it, 120 OIL ENGINES OIL ENGINES DRIVING DYNAMOS. 121 notice the lamps carefully. If the variations in the light are due to want of fly-wheel momentum, s"uch variations will be seen to coincide with the number of revolutions of the engine. Again, if the variation in the lights is only periodical, then this defect should be remedied by adjustment of the governor. Examine carefully the governing mechanism of the engine. If the variation is caused by the governor acting too slowly, then adjust so as to cause more rapid contact with the valve or other controlling mechanism. The cause of the trouble may not be, as already sug- gested, in the fly-wheel momentum or in the adjust- ment of the governor, but in the belt, which is fre- quently the sole cause of unsatisfactory lighting. The engine and dynamo pulleys over which the belt runs must be exactly in line with each other. The belt should be endless, or if jointed such joints should be very carefully made. A thick, uneven joint in the belt will cause a flicker in the lights each time it passes over the dynamo pulley. The belt should be allowed to run as loose as possible. The writer has seen belts running quite slack and most satisfactorily when the pulleys have been covered with specially prepared pulley-cover- ing material. In some instances in the dynamo itself may be found the cause of the variation in the voltage. If the commutator becomes unevenly worn, or if the brushes are not properly adjusted, unsteady lights will result, and then the commutator should be made of even surface and the brushes correctly adjusted. Oil engines can be stopped if desired by pressing button in the dwelling-house, an attachment being 122 OIL ENGINES. added to some engines which automatically turns the stopping handle. This is an advantage where the light is required late at night, and allows the attendant to leave the engine early, at the same time providing requisite illumination as long as required. AIR SUCTION. The noise created by the air being drawn into the cylinder has, in some cases, to be silenced. This can be accomplished by connecting the air-inlet pipe to wooden box containing space at least five times as great as the volume of the cylinder the sides of the box having holes which are lined with rub- ber. The total area of all these small inlet air holes should be at least three times the area of the air-inlet pipe to the engine. CHAPTER VI. OIL ENGINES CONNECTED TO AIR-COM- PRESSORS, PUMPS, ETC. THE use of compressed air is now being extensively applied as a means of power transmission, and it is coming more and more into favor in this connection also for actuating pneumatic tools, and for other pur- poses too numerous to mention. Many advantages are claimed for the combination of explosive engines con- nected to air-compressors as a motive power. Skilled attention is not necessary at all times. There are practically no standby losses, and the outfit can be easily transported. A small size compressor is shown in section at Fig. 590 made by the Bury Mfg. Co., Erie, Pa. The normal speed of these compressors being con- siderably less than. the normal speed of oil engines, they are operated by gearing or by belt from the engine. Fig. 60 shows an oil engine geared to air-compressor of the ordinary double-acting type. In this outfit the power necessary to actuate the compressor is trans- mitted by gearing from the engine crank-shaft to the compressor-shaft, which then revolves at a slower speed than the engine-shaft. This arrangement is con- FIG. 59 (To face p. 124.) OIL ENGINES CONNECTED TO AIR-COMPRESSORS. 125 sidered advantageous, because of the slower motion of the air-compressor valves as compared with the direct-connected outfit. In each of the illustrations the air-compressor cylinder is water-jacketed, the circulat- ing water being supplied by the small pump actuated from the engine cam-shaft, the water being first de- livered to the compressor cylinder, and thence to the oil engine cylinder. This outfit consists of 13 B. H. P. oil engine and "Ingersoll-Sergeant" double acting air- compressor having cylinder 8" diameter and 8" stroke, and running at 150 revolutions per minute, de- livering 70 cubic ft. of free air per minute at 70 to 80 Ibs. pressure. The horse-power required to operate a compressor delivering an actual amount of air at a given pressure can be found from the diagram at Fig. 6oc. The theo- retical horse-power required to compress loo cubic feet, delivered at various pressures up to 125 Ibs. can be taken directly from the curves on this diagram. In order to find the actual horse-power, the indicated efficiency and the mechanical efficiency of the com- pressor should be known. The indicated efficiency is the relation of the theoretical working diagram to the real indicated power. In the curve (Fig. 6ia), the actual air delivered is given. Approximately 10% should be added to allow for losses due to heating of the air, valve resistance and friction. Fig. 59 shows a 250 H. P. oil engine of the horizontal type direct connected to a two-stage air compressor in which the low pressure cylinder is 2o| inches diame- ter, and the high pressure cylinder 13^ inches, and is designed to furnish 1,275 cubic feet at 90 Ibs. pressure per minute. 126 OIL ENGINES. M 1-1 a a co W , 8 , e rr 8 rr^ i&imii pajoo^ }oi jiy -Xjuo uo;ssaaduio3 Suunp ajnssaa,j UBaj\; ^-0 000 OCO^O MU^^d,d ajniB-iaduiaj, }ut?isuo3 jiy 'Xiao uoissaaduzoQ Suijmp aanssajj ueaj^ ? Tfc" ?S 3" K M ^0 M M a 'I- n r^oo o ajjoajs -isd ajnssaaj UBBJ^ KM ^ ^M M M N CO ^00 M -t 1^. O :rT^= D 3 K Q Ooo r^ xri coo COO xri co IH W CO-3-l^-O N 'tO w ,,,/T^ C> O^co oo oo O O vn Tt rt -uo3 ^B jty qiiAV atunioA O O OOO w>\ncoOoo saaaqdsounv U I ajnssajcj oo o 't e aanssajj a^niosqy 4xAo r^-co c>4o4c>rf ajnssajj sSnvQ M M C. ( OIL ENGINES CONNECTED TO AIR-COMPRESSORS. u-> O ""> O m O "" O w> O **"> O m O in O w> M w I-H ON r>. m o \r> O N r^-C^w mO r-cc r- t^ w W Ooo -tmoci'ft"^ MOOcoc^MWinM t-KO 88" Safe '->& Required, Per Cent O 30.00 14-75 IOO. o. 0. 1000 28.88 14.20 97- 3- 1.8 20OO 27.80 13.67 93- 7- 3-5 3000 26.76 13-16 90. 10. 5-2 400O 25.76 12.67 87. 13- 6.9 5000 24-79 1 2. 2O 84. 1 6. 8-5 600O 23.86 "73 81. 19. 10. 1 7OOO 22.97 11.30 78. 22. u.6 8OOO 22.11 10.87 76. 24. I3-I QOOO 21.29 10.46 73- 27- 14.6 IOOOO 20.49 10.07 70. 30- 16.1 IIOOO 19.72 9.70 68. 32- 17.6 I2OOO 18.98 9-34 65- 35- 19.1 I3OOO 18.27 8.98 63- 37- 20. 6 I4OOO 17-59 8.65 60. 40. 22.1 15000 16.93 8.32 58. 42. 23-5 1 3 o OIL ENGINES. The efficiency of an air compressor is reduced when working at high altitudes. Table III. gives such de- preciation in efficiency at the different altitudes. FIG. 6 1 a. OIL PUMPING STATIONS Fig. 6ib shows the oil engine connected by friction coupling directly with a Goulds triplex power pump. The illustration shows a complete pumping station used in the oil fields for transporting crude oil from the oil fields to the oil refinery. Pressures as high as 900 to 1,000 Ibs. are frequently used in this work and it is customary for the engines to operate 24 hours per day continuously. The illustration shows several outfits, one of which is at all times held in reserve. This illus- tration is given to show one of the many applications of the oil engine used in connection with a pump. In these OIL ENGINES CONNECTED TO AIR-COMPRESSORS. 131 cases, the engine operates on crude oil, which is passed through the pipe line and effects great economy as compared with the steam plant. The oil engine is now very largely used for this purpose. OIL-ENGINE PUMPING PLANTS. Fig. 61 represents an oil-engine pumping plant as installed for supplying FIG. 62. town or village water-supply. This outfit consists of 13 H. P. oil engine connected by friction-clutch to the shaft of a triplex pump having cylinders 6\" diameter and 8" stroke. The amount of water delivered by this outfit is ap- proximately 165 gallons per minute, with total aver- age lift of 195 ft. The cost of fuel for running is 132 OIL ENGINES. about 13 cents per hour. Practically, no attention is required beyond starting the engine and occasional lu- brication. Fig. 62 shows a small outfit suitable for supplying water to a country-house, and consists of i| H. P. engine and pump capable of delivering 1200 gallons of water with 150 ft. total lift. To calculate the theoretical H. P. required to raise a FIG. 63. given amount of water, multiply the number of gallons to be delivered per minute by 8.3, which gives the weight; again, multiply by the total required lift in feet, and divide the result by 33,000, thus : Number of gallons X 8.3 X height of lift H. P. 33,000 OIL ENGINES CONNECTED TO AIR-COMPRESSORS. 133 Example: 165 gallons 195 feet lift 165 X 8.3 X 195 33,000 = 8 H. P. actually required to lift water. The friction of the moving parts of the pump has to be overcome, and for this and other losses allowance is usually made by figuring the efficiency of the pump (in the smaller size) at 60 per cent, to 70 per cent. OIL ENGINES DRIVING ICE AND REFRIGERATING MACHINES. Oil engines are now being used in connection with small ice and refrigerating machines. Fig. 63 represents a plant of this description, con- sisting of an oil engine belted direct to a refrigerating machine used in this instance for cooling a butcher's cold-storage box. The refrigerating machines are rated according to the amount of ice they are assumed to displace. A one-ton machine is one which will effect the same cooling in twenty-four hours which a ton of ice would do in melting. The chief advantage of the refrigerat- ing machine is that while the ice can only produce a temperature of 35 Fahr. and upward, the refrigerat- ing machine can be operated to produce any tempera- ture which may be desired. In the process of refrigeration, the work which the 134 OIL ENGINES. oil engine has to do is to drive a compressor, and there- fore the same principles may be applied to this machine as to the ordinary air-compressor already discussed. We need only to know how much gas has to be com- pressed and the conditions upon which to base the cal- culation for the work done in the compressor. It is the practice of refrigerating-machine makers to allow about 4.5 cubic ft. displacement per ton of refrigera- tion that is to say, a lO-ton machine is one having capacity of pumping 45 cubic ft. of gas per minute. In the case of the ordinary compressor, we have only to consider the final pressure, since the initial pressure is always that of the atmosphere. In the case of the refrigerating machine, however, this is not the case, for the gas being circulated in a closed circuit may have not only a varying final pressure, but also a vary- ing suction pressure. These pressures depend upon the temperatures obtaining in the cold room and in the condenser in a manner which it is not necessary to consider in detail. The initial pressure and the final pressure being known, the mean pressure may be cal- culated in the ordinary way. To facilitate this calculation, table No. IV. may be consulted. The vertical left-hand column gives the initial pressure corresponding to the temperatures named in the second column, these being the tempera- tures inside the cooling pipes. The top horizontal line gives the pressure corresponding to the temperatures in the second horizontal line. These temperatures are those obtaining in the condenser. OIL ENGINES CONNECTED TO AIR-COMPRESSORS. 135 00 2 CNOOONOO^-M r^.OOM ONONN ONOO OOO^o ONWON NMIO O ^" 00 W lO O^ t^ VO OO IH CO T^ VOVOVO t^t^t^OOOOOO ONONONi o rJ-O-^t- MNW ONONOO OOOOOO w 5 S, > S 2. 1C * cS -iro t-vooo OON NONOOOOON MiON a f^vOON N to t- ONMro Tf-Tfrl- lOiotO^ONOVO vot^t^- t^t^. c rt a J? 5- IT s;^-vS- ^o^^-^^ I - 00 JoS^ ^vSv? v^vS"^ SSv^ 9 t--'^-ON OOOOO rOPOtO >OT}-\O I oo' O rO 10 t^- O\ M pj M' pi pj O V a c j> V 5 ^g,^ t"^ ^t? o^. 6 TJ- ^- IT) ""O U"> LO IO tO TLO *LO ^-O to o o M 00 OO to *O *^ O *"* O Tt* M *O ** IX Tj- T}- ^- ^" to IO to to to to "^t" "^ S5 VOWO VO Tj- rj- T^-0000 VOVON M Nooo in which P = 67.02 pounds. L = 4.5 feet. A = 144 square inches = I sq. ft. Substituting these values, the horse-power is 1.32. No allowance is here made for friction, and in small refrigerating machines this should be extremely liberal. Moreover, on reference to the table it will be seen that the machine may happen to be called upon to work under conditions where the mean pressure will be very much increased ; such, for example, when the back pressure is 51 Ibs. and the high pressure is 218 Ibs. Under these circumstances the mean pressure will be 94.52 instead of 67.02. For these reasons it is not safe to provide for a refrigerating machine of small dimensions a power much less than about 3 H. P. per ton of refrigeration. Under ordinary conditions of running, less than this, and frequently only one-half of this will be required, but provision should be made for taking care of extreme conditions. OIL ENGINES CONNECTED TO AIR-COMPRESSORS. 137 FRICTION-CLUTCHES. Where engines of 10 H. P. or over are installed, it is a great advantage to have a friction-clutch pulley added. This can be attached either to the engine crank-shaft or to the intermediate or main shaft. Fast-and-loose pulleys are sometimes substituted for the friction-clutch. With either friction-clutch or fast-and-loose pulleys the advantages gained are, first, the ease with which the engine can be started, the loose or friction- clutch pulley only instead of the whole shaft has to be turned when the plant is started, and, secondly, in case of accident or other emergency necessitating the quick cessation of the revolving machinery, this can be ac- complished at once by simply moving over the handle of the friction-clutch and pulley. Otherwise without the clutch the heavy fly-wheels of the engine remain revolving for a minute or so after the fuel of the engine is turned off, and being directly connected by belt to the shafting and machinery, the whole plant is in mo- tion while the momentum of the fly-wheels exists. Friction-clutches are made of various designs by sev- eral manufacturers. That shown in Fig. 630, is espe- cially adapted for explosive engines. It consists of a carrier which bolts to the regular bosses on the fly- wheel of the engine, this carrier acting as the journal of the pulley, and the mechanism of the clutch is en- closed in the same. The clutch has a side grip. The pulley, otherwise loose, is thrown into connection with the engine fly-wheel by simply pushing in a spindle on which a hand-wheel revolves loosely. Two rollers are mounted on the end of the spindle, and bearing on 130 OIL ENGINES. these rollers are the levers which in turn are pivoted to the gripping plate and a lug on the levers abuts against the adjusting screw. The inward movement of the spindle forces these levers apart and draws the grip- ping plate in, thus gripping the pulley in a circular vise /ENGINE FLY WHEEL FIG. 630. between the flange on the carrier and the gripping plate. To release the clutch the spindle is pulled out, and thereby the strain on the levers is removed, thus allowing the pulley to run loose. This clutch is known as the B and C Friction Clutch Pulley. CHAPTER VII. INSTRUCTIONS FOR RUNNING OIL EN- GINES. THE attendant, in order to obtain the best results from an engine, should first fully understand the principle by which the engine he is running works and the conditions which it -is essential should ex- ist in the cylinder to procure proper explosion and combustion. These conditions are practically the same in all types of oil engines. The explosive mixture consists of hydrocarbon gas and atmospheric air, the gas being formed from kerosene oil previously gasefied or vaporized and properly mixed with air by one or other of the different methods, as described in Chap- ter I. This mixture is then compressed by the inward stroke of the piston before ignition with the two-cycle type of engine. The mixture is afterward ignited by hot tube, electricity, heated surfaces, or otherwise, as also described in Chapter I., and the required impulse is then obtained at the piston. If for any reason these conditions are not existing, proper explosion and com- bustion will not follow. The several reasons which prevent proper explosions being obtained are very fully described in Chapter III. on " Testing." I4O OIL ENGINES. The conditions necessary to insure proper working are as follows : (a) Oil supply to the vaporizer or combustion chamber delivered at the correct time, and in such quantity as to form proper explosive mixture. Effi- cient supply of air. (b) Sufficient pressure in the cylinder by compres- sion before ignition. (c) Correct ignition of the gases, the ignition tak- ing place at the proper time. CYLINDER LUBRICATING OIL. It is essential that a suitable lubricating oil be used for the piston. The great heat evolved in the cylinders of explosive engines renders this essential. The lubricating oil recommended for this purpose is a light mineral oil having a flash point of not less than 360 Fahr. and fire test 420 Fahr. Gravity test 25.8, and having a viscosity of 175 (Saybold test). If waste- oil filter is used, the oil filtered must not be employed for lubricating the piston at any time. The following are instructions as formulated by the makers of the different engines, each of the four types of vaporizers being here represented, as well as the different kinds of igniting devices. HORNSBY-AKROYD TYPE. The method of working is explained in Chap- ter IX., giving general description of these engines. The oil-tank in the base of the engine should be fillec 1 INSTRUCTIONS FOR RUNNING OIL ENGINES. 14! and the oil pumped up by hand until it passes the over- flow pipe. The water-tanks if used must also be filled to the top and the cylinder water-jacket also be full of water before starting. PREPARING TO START THE ENGINE. On those en- gines in which the vaporizer is partially water-jack- eted, the valve on the inlet water-pipe should be closed before commencing to heat the vaporizer for starting, and opened, or partially opened, when running. To HEAT THE VAPORIZER. A coil lamp is used (see illustration, Fig. 64) for this purpose; the lamp reser- voir should be nearly filled with oil. A little kerosene should then be poured into the cup containing asbestos wick under the coil and lighted. When this has nearly burnt out, pump up the reservoir with air by the air- pump, when oil vapor will issue from the small nipple, and on being lighted will give a clear flame. When it is required to stop the lamp, turn the little thumb- screw on the reservoir-filling nozzle and let the air out, and remove the lamp from the bracket. The nipple at any time can be cleaned with the small prickers which are supplied for this purpose. Should the U-tubes get choked up, the lower one can be gotten at by unscrew- ing the joint just below it, and the other one by screw- ing out the nipple from which the oil vapor issues. The heating of the vaporizer is one of the most im- portant duties to be attended to, and care must be taken that it is made hot enough before starting. The at- tendant must see that the lamp is burning properly for five or ten minutes, or sometimes a little longer, ac- cording to the size of the engine. If, however, the 142 -OIL ENGINES. lamp is burning badly, it may take longer to get the proper heat. It is most important that the lamp should be carefully attended to. FIG. 64. To START THE ENGINE. Place the starting handle to position "Shut," and work the pump-lever up and down until the oil is seen to pass the overflow-valve. INSTRUCTIONS FOR RUNNING OIL ENGINES. 143 Then turn the handle to position " Open," work the pump-lever up and down again, one or two strokes, then give the fly-wheel one or two turns, and the engine will start readily. There is also a handle upon the cam-shaft, which, when starting the engine, must be placed in the position marked " To Start," and imme- diately the engine has gotten up speed this handle should be placed in position marked " To Work." FIG. 65. (See Fig. 65.) When it is required to stop the engine, turn the starting handle to the position marked " Shut." If too much oil is pumped into vaporizer before start- ing it will be difficult to start up. OILING ENGINE. See that the -oil-cups on the main crank-shaft bearings are fitted with proper wicks and with other oil-cups are filled with oil. Oil the 144 OIL EXGIXES. small end of the connecting-rod which is inside the pis- ton, also the bearings on horizontal shaft and the skew- gearing, the rollers at the ends of the valve-levers and their pins, and the pins on which the levers rock, the governor spindle and joints, the bevel-wheels which drive same, and the joints that connect the governor FIG. 66. to the small relief-valve on the vaporizer valve-box. For such purposes, none but the best engine oil should be used. OIL-PUMP. When the engine is working at its full power the distance between the two round flanges A and B on the pump-plunger should be such that the gauge " i" will just fit in between the flanges. (See INSTRUCTIONS FOR RUNNING OIL ENGINES. 145 Fig. 66.) The other lengths on the hand-gauge marked " 2" and " 3" are useful for adjusting the pump to economize oil when running on a medium or a light load. Do not screw down the pump packing tight enough to interfere with the free working of the plunger. RUNNING ENGINES LIGHT OR NEARLY So. When engines are required to run with light or no load, it is best to alter the stroke of the pump to supply only suf- ficient oil to keep the engine running at full speed, so that the governor occasionally reduces the oil. The inlet water-pipe to the vaporizer-jacket should be closed when running light also. AIR-INLET AND EXHAUST VALVES. See that the air-inlet and exhaust valves are working properly and drop onto their seats. They can at any time, if re- quired, be made tight by grinding in with a little flour of emery and water. The set-screws at the ends of the levers that open these valves must not be screwed up so high that the valves cannot close ; this can be ascer- tained by seeing that the rollers at the other end of the levers are just clear of the cams when the project- ing part of the cams is not touching them. (See Fig. 67.) VAPORIZER VALVE-BOX. In this box there are two valves. The vertical one is regulated by the governor, and when the engine runs too fast the governor pushes it down, thus opening it and allowing some oil to over- flow into the by-pass, which should only allow oil to pass when the governor presses it down, or when the starting handle is turned to " Shut." The horizontal 146 OIL ENGINES. valve in this box is a back-pressure valve, and should a leakage occur it may be discovered by slightly open- ing the overflow-valve (by pressing it down with the hand), when, if there is a leakage, vapor will issue from the overflow-pipe, and in that case the valve should be examined, and, if necessary, be taken out for inspection and ground on its seat with a little emery flour and water. If the horizontal valve and sleeve are taken out, care should be taken, in replacing them, to use the same thickness of jointing material as before. OIL-PIPES. The pipe from the pump to the vapor- izer valve-box has a gradual rise from the pump; if FIG. 67. otherwise, an air-pocket would be formed in which air would be compressed upon each stroke of the pump, and thus allow the oil to enter slowly and not as it should do, suddenly. If the oil gets below the filter at any time, work the pump by hand a few minutes, holding open the overflow-valve in the vaporizing valve-box, so as to get the air well out of the pipes. The oil-filter should be taken out and cleaned occa- sionally. INSTRUCTIONS FOR RUNNING OIL ENGINES. 147 SPRAY HOLES. It may be desirable to take off the vaporizer valve-box and clean the little hole or holes through which the oil issues. The reamers, or small wires supplied, are not for increasing the size of the hole, but are simply for cleaning it at any time. TESTING OIL-PUMP. See that the pump gets its proper oil supply. Disconnect the oil-supply pipe union attached to vaporizer valve-box, and give the FIG. 68. pump two or three strokes so as to pump oil up ; then press the thumb firmly on the end of the pipe, as shown in illustration, Fig. 68. Pump both by a sudden jerk, and afterward by a steady pressure. If the plunger yields to a sudden jerk and no oil has gotten past the thumb over the top of the delivery-pipe, then the pump or the pipes contain air. If the plunger does not yield to a sudden jerk, but slowly falls under a constant pressure, then the suction-valves of pump are 148 OIL ENGINES. not tight. If necessary, the valve-seats can be renewed by lightly driving the cast-steel ball valves onto their seats with a small copper punch. If it is required to see that the vaporizer valve-box is in order, take off the vaporizer valve-box body and sleeve, and connect them to the oil-supply pipe from the pump, so that the jet from the spraying hole can be directed where it can be seen. Work the pump by hand, when the jet produced should be clear, with distinct and abrupt pauses be- tween each delivery. THE GOVERNOR " HUNTING." This may be caused by the joints or spindle of the governor becoming bent, dirty, or sticky, and requiring cleaning. If the pump is not giving a regular supply of oil, it may sometimes cause the governor to hunt, and the engine would run irregularly. This may occur when the engine is first started. THE CROSSLEY PATENT TYPE. STARTING. Heat the ignition-tube by means of the lamp in the usual way. The pressure (about 60 Ibs.) necessary to raise the oil to the lamp in this engine is taken from the oil-tank, the air pressure be- fore starting being created by hand. This lamp heats both the ignition-tube to a good red heat and vaporizer blocks to less heat simultaneously. The necessary pressure to raise the oil to the lamp is maintained by the pump actuated from the cam-shaft when the en- gine is running. PRIMING CUP. Fill the little brass priming cup on INSTRUCTIONS FOR RUNNING OIL ENGINES. 149 the top of the vaporizer cover with oil ; open the valve and let the oil pass through into the vaporizer, and then shut it again. Leave the wire on the chain out of the measurer. Place the exhaust roller over to engage with the one-half compression cam ; turn the fly-wheel until the crank-pin is about one inch above the hori- zontal (both valves being closed) ; open the stop- valve on the end of air-receiver ; connect up the oil-pump by replacing the back-pin, having first made a few strokes with the hand-pump until the oil-pipe is full up to the measurer, and turn the quadrant on air-throttle valve. The engine is now ready to start, and the air under pres- sure from receiver may be let in. Loosen the screw of starter valve ; open the valve by means of the loose lever, and hold open until the crank has just passed the verti- cal position. This impulse will be sufficient to turn the fly-wheel a few times, during which the piston will re- ceive regular impulses. The exhaust roller may then be moved off the one-half compression, when full speed will be steadily attained. As soon as convenient the screw on the starting valve may be unscrewed to allow the receiver to be- come recharged again. Should the engine miss explo- sions and fail to attain full speed, then turn the lid of measurer partly around and give a little extra supply of oil from a hand-can. AIR SUPPLY. At full speed the air-throttle must be opened to admit more air, and the amount must be judged as to whether the engine ignites its charges or not ; too much air will cause it to miss fire too little air causes too sharp firing. If the receiver is not 150 OIL ENGINES. charged, and it is required to start engine by hand, pull around the fly-wheel and get up as much speed as pos- sible before putting the governor blade in position for engaging with the governor mechanism which opens the gas-valve. VAPORIZER BLOCK. The vaporizer block must be well heated previous to starting; otherwise unvapor- ized oil will be carried over into cylinder, and thus make starting uncertain until the oil has all passed away in evaporation. This may also cause puffs of vapor to rush out of the air inlet at the top of the chimney, preceded by a slight explosion in the vapor- izer block. This is caused by late ignition in cylinder, and is due to insufficient vaporization or to the ignition- tube not being hot enough. VAPOR VALVE. If small puffs of vapor issues out of the air-pipe of the chimney every other revolu- tion while the engine is running, it is a proof that the vapor-valve is not tight and must be cleaned and ground on its seating. CAMPBELL OIL ENGINE. STARTING. Before starting the engine, see that the vaporizer is thoroughly well heated. The lamp under the vaporizer should burn with a long, bright flame. When the vaporizer is sufficiently heated, throw the governor drop-lever down, thus holding the exhaust- valve open and relieving the compression. While this lever is held down, give a quarter or a half turn of the INSTRUCTIONS FOR RUNNING OIL ENGINES. 15! oil-cock ; then turn the fly-wheel quickly four or five revolutions, and allow the governor drop-lever to be free. It will swing up clear of the exhaust-lever and allow a charge of air and oil to be driven into the vapor- izer ; the engine should then commence working. After the engine has started, turn on a little more oil. If the oil taken into the vaporizer should not explode prop- erly, the oil-cock must be shut and opened again quickly to allow any superfluous oil which has lodged in the vaporizer to be drawn out of it and vaporized. When using a heavy oil, open the inlet-valve to allow more air to flow into the vaporizer. AIR AND OIL SUPPLY. Too much oil passing to the vaporizer will cause the engine to miss exploding or to explode irregularly. To increase the air supply, slacken the nuts and tension of air-inlet valve; by tightening the nuts and spring, the air supply is de- creased. IGNITION-TUBE. See that the inside of the ig- nition-tube is kept clear from oil, and keep all the valves clean and the governors free from oil and dirt. When the engine is running properly, the quantity of oil required is the same, whether the engine is running at light or heavy load. GOVERNORS. The governors . cut out some of the charges at light loads and admit more charges of oil at heavy loads ; each charge, however, has the same com- position of vapor and air. 152 OIL ENGINES. THE PRIESTMAN TYPE. STARTING. Open the drain-cock in the vaporizer and see that the vaporizer contains no oil ; then close the cock. Fill the oil-tank to the small upper-pet cock, through the strainer provided and screw down the re- lief air-valve. Lubricate the piston wrist-pin and the crank-bearing between the fly-wheels. Drop a little oil on the pump-piston and in the oil holes of the bearings of the large gear-wheels, the eccentric, and all other bearings. Mineral oil must not be used on the governor oil spindle which projects into the spray-maker. ELECTRIC IGNITER. Raise the electric fork-handle slightly. This is done in order to produce the igniting spark somewhat later for starting than is required when the engine is running at full speed. Turn the fly-wheels forward until the small knob on the cam-shaft has just passed the contact with the forks, and the crank-pin is then just clear of the large gear-wheel. HEATING VAPORIZER. Heat the vaporizer until the lower part of the feed-pipe leading to the inlet-valve is too hot to be comfortably held by hand. When the va- porizer is sufficiently heated, pump up 6 or 8 Ibs. gauge air pressure in the oil-tank with the hand- pump ; open the oil-cock, and then give the fly-wheels a few turns with the starting handle. After starting, move the electric fork-handle down as far as it will go. AIR SUPPLY. Set the air-relief valves for giving about 8 to 10 Ibs. air pressure in the oil-tank. The most suitable running pressure in a given locality as indi- INSTRUCTIONS FOR RUNNING OIL ENGINES. 153 cated by the gauge, has to be determined by experiment. With the air pressure too low or too high, the engine may miss explosions. The best test for this is the color of the ignition-plug. When the pressure is right, the plug will be perfectly clean. If the plug is coated with an oily black substance, it is a sign of too much oil that is, too high a pressure. To stop the engine, turn off the oil-cock. When stopped, see that the electric circuit is not closed, or the battery energy will be wasted. GENERAL REMARKS. If an oil engine is working properly and efficiently, it should run smoothly to the eye, without knocking either in the cylinder or bear- ings. The piston should continue to work clean and be well lubricated, without any apparent carbon or gummy deposit. The exhaust gases at the outlet-pipe should be invisible or nearly so. The explosion should be regular and should be only reduced in pressure when the governor is reducing the explosive charge and al- lowing only part or none of the charge of oil to enter the cylinder. If the piston is black and gummy, or if the exhaust gases are like smoke, then the combustion inside the cylinder is recognized as being incomplete, and the cause should at once be ascertained and remedied. Bad combustion may be due to several reasons, but is chiefly caused by improper mixture of air and gases in Jhe cylinder, due either to too much oil entering into the vaporizer or to insufficient amount of air being drawn in mixed with the hydrocarbon gas. To remedy this defect, examine the oil-inlet valves or spraying de- 154 OIL ENGINES. vice carefully ; also see that air and exhaust valves are allowed to drop freely on their -seats, and that springs or other mechanism for closing the valves are in good shape. Examine piston-rings and ascertain that the rings are in good order and are not allowing leakage of air to pass them. REGULATION OF SPEED. To alter speed of the en- gine with the hit-and-miss type of governor, the spring is strengthened or the weight reduced to increase speed. The weight is effectively increased by moving it toward the end of the lever away from the fulcrum- pin, and vice versa to reduce speed. The strength of the spring is increased by tightening down the thumb- screw nut. With the Porter type of governor where counterbalance with movable counterweight is pro- vided, the speed is accelerated by increasing the sup- plementary weight, or by placing it nearer the end of the lever. If the centrifugal force of the revolv- ing weights is controlled by a spring instead of weight, then the speed is increased by strengthening the spring. REVERSING DIRECTION OF ROTATION. In order to reverse the direction of rotation of an explosive engine, it is necessary to change the relative position of the cams actuating the air and exhaust valves and fuel supply so as to alter the periods of opening and closing of these valves, and also^to change the period of fuel supply. In those engines in which one cam controls both the air-inlet valve and the fuel supply, the shift- ing of this one cam alone effects the change necessary.* Where the fuel supply is operated separately, the cam *The position of the exhaust cam to conform to the diagrams in Fig. 69 is changed by alteration of the gear- ing in the cam shaft. INSTRUCTIONS FOR RUNNING OIL ENGINES. 155 or eccentric controlling this mechanism must be moved correspondingly with the air-valve cam. The following diagrams give the correct positions FIG. 69. of the opening and closing of the valves when the engine is running in each direction, and the cams as set for each case are shown in Fig. 69, the slot for key- way in the air-inlet cam having been changed only. 156 OIL ENGINES Where the air-inlet valve is automatic and the ex- haust valve only is actuated from the crank-shaft, then, to reverse the direction of rotation of the crank-shaft, the position of the exhaust-cam only is changed, corre- sponding to the position as marked for the exhaust valve in diagram shown in Fig. 69. The lip for regulating the compression when start- ing the engine only, which is usually found on the ex- haust cam, will require adjustment when the engine is reversed so as to close the exhaust valve when ap- proximately one-half the compression stroke has been completed. The direction of rotation for which the cams of the engine are adjusted can be ascertained by turning the fly-wheel until the exhaust cam commences to open the exhaust valve. If the exhaust valve is opened when the crank-pin is above the outward cen- tre, as shown on the diagram to the right in Fig. 69, then the direction of the engine is "over" or away from the cylinder. When the exhaust valve opens below the centre of the crank-pin, as shown in diagram to the left in Fig. 69, then the direction of rotation of the fly- wheel will be "under"; that is, the upper part of the fly-wheel will revolve toward the cylinder. CHAPTER VIII. REPAIRS. OIL ENGINES as made by most of the makers are of substantial construction, with ample bearing surfaces, and consequently require few repairs. The lower initial pressures of explosion evolved in oil engines as com- pared with some gas and gasoline engines considerably lessens the severe shock to the piston and to the crank- shaft bearings and connecting-rod bearings. All machinery requires repairs more or less according to the care that it receives, and oil engines are not an ex- ception to this rule. THE PISTON should be drawn out occasionally ; this is done by uncoupling the connecting-rod crank end bearings and pulling the piston out. Chain-block is sometimes added to the installation of large engines, and it is a very useful adjunct when it is required to take out the piston or when other repairs have to be made. Where no arrangement of this kind is available when the piston is to be taken out, wooden packing is placed in the engine-bed, on which the piston can rest as it is drawn out. Care should be taken that the weight of the piston as it is drawn from the cylinder does not fall on the piston-rings or they may thus be broken. 158 OIL ENGINES. With the vertical type of engine the piston is taken out from the top, the cylinder head and other parts having been removed. The piston should be washed with kerosene and well cleaned. When putting piston back in place, each ring should be put separately in exact position in its groove as regards the dowel-pin in piston groove before the ring enters the cylinder. The piston, the rings, and the inside of the cylinder must all be carefully cleaned and well lubricated with proper oil before being again put in place. Where the rings require cleaning, this can be accomplished by washing with kerosene. If, how- ever, the piston-rings are to be taken off the piston, they must be separately sprung open by having pieces of sheet metal about 1-16" thick and about \" wide in- serted between ring and body of piston. Air and exhaust valves should also be periodically taken out, cleaned and examined, and, if necessary, re- ground in. Powdered emery or glass powder is con- sidered satisfactory to grind the valves in with. Care should be taken, in replacing valves, that they are clean and free from rust or carbon, and are allowed to drop on their seats freely and do not stick in their guides. The crank-shaft bearings will periodically require taking up as they show signs of wear and commence to knock or pound. Usually, for this adjustment, liners are left between the cap and the lower half of bearings. These liners can be occasionally reduced in thickness, so that the cap is allowed to come down close on to the shaft. Great care must be taken, in REPAIRS. 159 tightening down the bearing again after adjustment, that it is not bolted down too tight on the shaft bear- ings; otherwise heating will result and the bearings and journal may be cut and damaged in running. The connecting-rod bearings will require adjustment more often than the crank-shaft or main bearings. FIG. 70. When this is necessary, the engine will be heard to knock at each revolution, and then the bearing should be taken apart at the crank-pin bearing and about 1-64" filed off. (See A, Fig. 70.) As with the crank- shaft bearings, great care, in putting bearing back in place, must be exercised, first to see that it is thor- oughly clean and free from dirt, and also, when read- justed, that it has a slight motion sideways and can thus be moved by hand. When fitting new piston-ring, it is well to place the 160 OIL ENGINES. ring in the cylinder correctly; it should have slight space, about 1-64" left for the expansion between the joint which will take place when heated in working. After fitting new worm or spur gearing to the valve motion, the positions of the cams should be tested by turning the fly-wheel over by hand. The correct posi- tions of the cams are shown on diagram, Fig. 32. The oil-filter requires occasional renewing; this can be made of muslin placed between wire gauze, as shown in Fig. 28. The oil-supply pump-valves, if they consist of steel balls, can be refitted to their seats by being tapped when in place with copper plug or piece of wood. When renewing governor parts, care must be taken that the new part is free and works without friction ; this is very essential where close regulation of speed is required. CHAPTER IX. OIL ENGINE TROUBLES. THE requirements for proper working of the oil en- '" gine have been already mentioned in Chapter VII. as follows : Proper oil and air supply to the cylinder or vaporizer, proper mixture or combination of air and vapor, correct and properly timed ignition. Defects which may cause improper working have also been re- ferred to in Chapter III. on testing. The following remarks are chiefly applicable to the operator, and refer to difficulties which may possibly be encountered in the actual use of the oil engine. TROUBLES OF IGNITION. THE ELECTRIC IGNITER. This igniter is described in Chapter I. Failure in operation is generally due to the following causes : BREAKAGE IN ONE OR OTHER OF THE ELECTRICAL CONNECTIONS. To discover the breakage test with a length of wire in the hands bridged across between the terminals of the connection which is thought to be de- fective, the circuit through the cam-shaft being closed. If a spark is then given off the defect has been located and a new connection should be put in place. In l62 OIL ENGINES. some instances a spark is not produced because the bat- tery is run down ; this defect can be ascertained by test- ing the battery with a small volt meter or by bringing both terminals in contact one with another from the battery; a strong spark should then be seen. If the battery is run down, it must, of course, be recharged or renewed. The terminals in the cylinder must al- ways be clean and free from carbon deposit. This is important especially with a jump-spark plug igniter, as the terminals in the cylinder will sometimes become carbonized or corroded, thus forming a path for the current to flow across without causing any spark. Failure to obtain electric spark ignition may occur from bad insulation of the plug. In this case a new plug should be substituted for the defective one. In some instances the electric spark is not procured be- cause the plug is short-circuited, due to moisture. To overcome this the plug must be thoroughly cleaned and dried out or a new plug must be substituted. With the type of igniter having movable electrode, owing to friction or carbonizing, the two electrodes may be prevented from touching. In this case the moving electrode should be eased or cleansed and allowed to come freely in contact with each other. The timing of the ignition with the electric igniter is regulated by altering the time of contact. The period of ignition varies according to the speed of the engine. With a high speed the ignition should take place just before the crank-pin arrives at the dead centre ; with a slow-speed engine the time of ignition can be slightly later ; that is, the ignition may take place as the crank- OIL ENGINE TROUBLES. 163 pin passes the dead centre. When starting the engine, the ignition is retarded until the normal speed of the engine is attained. TUBE IGNITER. Troubles with this form of igniter are generally due to corrosion internally of the tube. This is remedied by taking the tube out and thor- oughly cleaning it. In other instances ignition is not obtained because the tube is not properly heated. The temperature of the tube should be maintained at a good red heat. With the tube igniter it is essential that the gases can properly enter it. The timing of ignition with this form of igniter can be varied by changing the length of the tube or by altering the part of the tube which is heated. If an earlier ignition is re- quired, the tube should be heated nearer to the cylin- der end, or a shorter tube should be used. If it is re- quired to retard the time of ignition, the tube can be heated further from the cylinder, and accordingly the gases to be ignited will not come in contact with the heated part so rapidly. AUTOMATIC IGNITER. In order to procure proper ignition with this form of igniter, it is essential that the compression of the air and gases is efficient. This pressure varies in different types of engines, and, as will be seen from the indicator cards shown in Chap- ters III. and X., is from 50 to 70 Ibs. The mixture of air and oil vapor must also be correct. Failure to obtain an ignition with this type of engine is usually due to too much oil having been allowed to enter the vaporizer or cylinder, or to the fact that no oil at all has entered- the vaporizer, or, as already stated, to fail- 164 OIL ENGINES. tire to obtain proper compression. Ignition, of course, cannot be obtained when starting unless the vaporizing chamber or retort has been properly heated. OIL SUPPLY. If the oil supply is defective, the fault can be ascertained by careful examination. Discon- nect the oil-supply pipe and see that oil flows freely from the tank. Sometimes the oil filter in the tank will become clogged and will not allow the oil to flow through it. If oil is supplied by a pump, then test the pump, as shown on page 147. Failure of the pump to operate properly is due to leaky valves or to the packing around the plunger, allowing air to leak by, and thus the proper pressure in the pump is lost. The oil supply may -fail by reason of leakage in the oil pipes. This may easily happen where the oil tank is placed below the level of the engine and the oil has to be raised from the tank by pump. In such a case the engine may operate when the pump is working at full stroke, whereas otherwise no oil will be delivered to the cylinder or vaporizer. AIR SUPPLY. Defective air supply is due to leak- age in the piston-rings, piston, or to leakage in the air and exhaust valves. The compression in the cylinder is, of course, governed by the air supply, and a leakage in the valves or piston can be tested by simply turning the engine backwards. With proper compression it should be difficult to turn the crank-pin past the in- ward dead centre during the compression period. KNOCKING. An engine working properly should be quiet in operation. Knocking may be due to either loose bearings in the connecting-rod, piston or crank- OIL ENGINE TROUBLES. 165 pin end, to loose fly-wheel keys, or to improper timing of ignition. The first two defects can be ascertained by examination. The timing of ignition is most easily ascertained from the indicator card. (See page 76.) Loss OF POWER. This may be due to increased fric- tion in the engine, which friction may be caused by bad lubrication of the piston or the piston becoming gummed up, due to improper combustion or to the use of improper lubricating oil. (See page 140.) Loss of power may also be due to heated bearings. Either of these causes can be easily ascertained. Insufficient oil or fuel supply due to the wearing of the moving parts and consequent reduction of the pressure of explosion is sometimes responsible for the loss of power. To overcome this the supply of fuel can be slightly in- creased. That the proper amount of fuel is being sup- plied can be roughly ascertained by the color of the exhaust gases. If too much oil is supplied the ex- haust gases will be plainly visible. With the correct oil supply the exhaust gases will be invisible or near- ly so. PISTON BLOWING. This is due to the various fol- lowing causes : Improper lubrication, to the piston- rings leaking, to the piston-rings having become clogged, or to the cylinder having become cut or worn. It is also sometimes due to over-expansion of the cylinder, caused by over-heating and insufficient water supply. If the blowing of the piston cannot be reme- died by proper lubrication or by thoroughly cleaning the piston-rings new piston-rings must be put in place. In some cases it is even necessary to re-bore the l66 OIL ENGINES. cylinder and have new piston and rings. The blowing of the piston may be also caused by improper combus- tion due to too great an oil supply or insufficient air supply. Escape of vapor from the open end of the piston, which is thought to be a leakage, is sometimes caused by the splashing of the oil on the overheated bearings or the heated portion of the piston. This can be ascertained by stopping the engine. If vapor con- tinues to escape when the engine is at rest, its cause is apparent, and then the supply of lubricating oil to the cylinder can be reduced. EXPLOSIONS IN THE MUFFLER OR SILENCER. A loud report may sometimes be heard, caused by the ex- plosion in the exhaust pipe or muffler. This is due to the gases passing through the cylinder unconsumed and then becoming ignited in the silencer. It is not possible to create a dangerous pressure in this way, and as the silencer is usually a heavy cast-iron cham- ber and always open to the atmosphere, the worst re- sult is annoyance of the noise. Explosions in the si- lencer or exhaust pipe can be obviated by reduc- ing the oil supply, and are often caused by starting the engine before the igniting apparatus is sufficiently heated to cause proper ignition. LEAKAGE OF WATER. Engines will sometimes re- fuse to operate due to this cause. Leakage of water can easily be ascertained by examination of the piston and cylinder, or the piston can be withdrawn from the cylinder. Testing of the water-jackets has already been explained in Chapter III., and the leakage, if found, must be remedied by new joints. If such leak- OIL ENGINE TROUBLES. 167 age is due to defect in the casting, it can sometimes be remedied by drilling out the defective material and by tapping and plugging the cylinder walls or other de- fective part. This work, however, requires consid- erable care to thoroughly overcome the leakage. CHAPTER X. VARIOUS ENGINES DESCRIBED. THE CROSSLEY OIL ENGINES FIGURE 71 illustrates the Crossley oil engine having one heavy fly-wheel. Their "lampless" type of engine is shown in Fig. yia, which has their latest vaporizer shown in section at Fig. 3 and two heavy fly-wheels suitable for electric lighting purposes. The method of vaporizing and igniting used with the Crossley engine is fully described in Chapter I. devoted to that subject. The fuel oil-tank is placed against the cast-iron base of the engine, and the oil is pumped to the vaporizer in the usual way by an oil-pump actuated by the cam- shaft and in regular fixed quantities, but the fuel is allowed to enter the vaporizer only in exactly the proper quantity, the oil supply being controlled by the special measuring device, which consists of an inlet automatic valve leading to the vaporizer and an over- flow-pipe leading back to the oil-tank. If the oil supply from the pump at any time is greater than the amount of oil which should enter the vaporizer, the fuel is re- 170 OIL MXGIXMS. jected by the oil-measuring device, which is actuated by the partial vacuum in the cylinder during the air- Diagram from the Crossley Engine: Revolutions per minute. 180; M. E. P., 69 Ibs. ; compression pressure, 48 Ibs. ; maximum pressure, 240 Ibs. Diagram from Crossley Engine: Revolutions per minute. 180 ; M. E. P., 50 Ibs. ; compression pressure, 50 Ibs. ; maximum pressure, 180 Ibs. suction period. The oil then returns through the over- flow-pipe to the tank. VARIOUS ENGINES DESCRIBED. 171 The centrifugal governor is actuated by separate gearing and horizontal shaft direct from the crank- shaft, and the governor regulates the speed of the engine by acting on the hit-and-miss system, and con- 172 OIL ENGINES. trols the vapor inlet-valve to the cylinder. Thus, if the required speed of the engine is exceeded, the vapor-valve is not opened, and accordingly only air is drawn into the cylinder through the air-inlet valve on the top of the cylinder, which is actuated by eccentric from the cam-shaft. No oil vapor is drawn into the cylinder, and the next explosion is missed. The lamp for heating the vaporizer receives its supply from the oil-tank placed against the base of the engine. The oil for the lamp is supplied by a separate pump, both oil- pumps being actuated from the same eccentric. THE CUNDALL OIL ENGINE. This oil engine is illustrated in Fig. 72, and it has oil-tank in the cast-iron base of engine, the fuel be- ing pumped to the vaporizer in the usual way, the oil supply being regulated by a small adjustable thimble inside the cup on the vaporizer. The vaporizer and tube are heated by separate lamp supplied from oil-tank placed above the engine by gravity feed. Both air and exhaust valves are actuated from the horizontal cam- shaft in the usual way. The centrifugal governor is operated by bevel-gearing from the cam-shaft and con- trols the speed by acting on the oil-inlet valve. THE CAMPBELL OIL ENGINE. Fig. 73 illustrates larger-sized engine fitted with one fly-wheel only and outside bearing suitable for electric- OIL ENGINES. lighting purposes. The vaporizing and igniting appa- ratus of this type is described in Chapter I. The fuel Light-load diagram taken from Campbell engine: Cylinder, 9.5" in diameter; stroke, 18"; revolutions per minute, 210; M. E. P., 55.9 Ibs. Full-load diagram from Campbell Engine : Cylinder, 9.5" in diameter; 18" stroke; revolutions per minute, 210; M. E. P., 69.25; compression pressure, 55 Ibs.; maximum pressure, 232 Ibs. oil-tank is placed on the top of the cylinder and the VARIOUS ENGINES DESCRIBED. 1/5 fuel is fed by gravitation to the vaporizer and to the heating lamp, there being no oil-pumps. There are only two valves the air-inlet valve, which is automatic, and the exhaust-valve, which is operated by the cam, which is actuated by spur-gearing from the crank-shaft, the necessary power to open the valve being transmitted through the horizontal rod in compression. The cen- trifugal governor is mounted on separate horizontal shaft, and is actuated by separate gearing from the crank-shaft. The speed of the engine is controlled by suitable device which is inserted by the action of the governor between the exhaust-lever and the stationary bracket when the normal speed is exceeded, thus hold- ing open the exhaust-valve and preventing any of the oil vapor and air from entering the cylinder during the suction period. PRIESTMAN OIL ENGINE. Fig. 74 represents this type of engine as made by Messrs. Priestman in the United States. The design of this engine is upon the " straight line" principle, and differs from the other engines herein described. In this engine, both the fly-wheels are ar- ranged to be inside of the main shaft bearings instead of at each side of the frame, as is usual. The makers claim great advantages for this design, inasmuch as the strain on the bearings is minimized. The crank-pin is placed between the two fly-wheels, the hub of each fly- 176 OIL ENGINES. wheel becoming the cheek of the crank. The oil-tank is placed in the bed of the engine ; an air pressure of five or six pounds is always maintained in this tank by means of the separate air-pump actuated from the cam-shaft by eccentric. The vaporizer spraying and igniting devices are fully described in Chapter I. The governor is driven by belt from the crank-shaft FIG. 74- and is of the centrifugal or pendulum type. The speed of the engine is controlled by suitable mechanism acting on the throttle-valve regulating the supply of oil and air entering the vaporizer. The air-inlet valve to the cylinder is automatic, the exhaust-valve being actuated by horizontal rod operated from a cam placed VARIOUS ENGINES DESCRIBED. 177 on the cam-shaft. This engine, it is claimed, requires little or no lubrication for the piston. The following test was made in the Engineering Laboratory at University College, Nottingham, Eng- land, on single-acting horizontal English type of Priestman oil engine having cylinder lof" dia. and aZo re c trrr > 120 lifk QJ Q3 Or? P^t O*V. -GX0 C4*2>>fee>&_ t INDICATOR CARD OF THE PRIESTMAN ENGINE. 14* stroke, capable of developing lof actual or brake horsepower at 160 R. P. M. The test was made after seven years' service of the engine using American kerosene, known as Royal Daylight, specific gravity 0.792 at 60 Fahr. and having flash point 83 Fahr. The effective work recorded is the effective indicated 178 OIL ENGINES. pressure in the cylinder, the back pressure of the ex- haust and suction strokes being deducted.* TABLE V. TRIALS OF PRIESTMAN OIL ENGINE, DEC. Q, IpOO (ROBINSON). Duration of run (hours) 2 Revolutions per min. mean 160 Pressure before ignition (above atmos- phere), Ib. per sq. in 20 Mean pressure, Ib. per sq. in 44 Mean back pressure (pumping strokes) Ib. per sq. inch 3 Net effective pressure 41 Net effective indicated H.P 10.5 Brake or actual H. P 8.4 Engine friction H. P 2.1 Mechanical efficiency per cent 80 Oil used per hour (total Ib.) 8.82 per I. H.P. Ib 0.84 per B.H.P. Ib 1.05 Cooling water through jacket, Ib. per min. 22.5 Cooling water rise in temp. 57 to 113 Fahr - 56 THE MIETZ & WEISS ENGINE. This engine is illustrated in Fig. 75. It works not, as some other engines described herein, on the Beau de Rochas cycle, but on the two-cycle princi- ple that is, an explosion is obtained in the cyl- inder at each revolution of the crank-shaft. As the oil-tank is above the cylinder, fuel is supplied to the smaller engines partly by gravitation the quantity in- *"Gas and Petroleum Engines," by Prof. Wm. Robin- son, pp. 688. FIG. 75 (To face p. 178.) VARIOUS ENGINES DESCRIBED. 179 jected, however, into the cylinder being regulated by small oil supply pump. Where required, the oil tank can be placed below the level of the engine. A sec- tional view of the horizontal engine is shown at Fig. 750. The Mietz & Weiss marine engine is also shown at Fig. 75^ made vertical of single or multi- cylinder type. It operates on a similar plan of opera- tion to the horizontal engine, a special feature of the multi-cylinder type being the use of one oil pump for the injection of the fuel into one or more cylinders. HORSE-POWERS FIG. 7ib. This vertical marine type engine is made in sizes up to 200 H. P., and is also used for industrial purposes direct-connected to electric generators and for general power purposes. The fuel is injected into the cylinder of the Mietz & Weiss engines with some steam. The steam being generated in the water jackets surround- ing the cylinder, which are allowed to rise to a tem- perature necessary for generating the steam. The oil is vaporized in a hot chamber shown in the accom- panying sectional illustrations placed at the back of the cylinder, which is heated for a few minutes in starting by independent lamp. Afterwards the heat 180 OIL ENGINES. created by constant combustion maintain the igniter at proper temperature automatically. The governor of the improved Mietz & Weiss en- gine is of the centrifugal type, and acts through a vari- able stroke on the kerosene pump, graduating the charge for varying loads. The governor weight is arranged near the shaft at the hub of the fly-wheel, to which it is pivoted at one end, the other end being secured to an adjustable spring, the tension of which determines the speed. The eccentric is free to slide at right angles to the shaft, and, being pivoted to the ex- treme end of the governor weight, receives a slight turning movement ahead from no load to full load. The regulation with this governor is extremely close in direct electric lighting service, where many of these engines are in use, either belted or direct-coupled to generators. The deficiency of pressure in the crank-chamber is used to raise the lubricating oil from an oil well placed below the sight feed oilers which supply oil to the cyl- inder and crank-chamber. The crank bearings are lu- bricated by means of ring oilers. These engines are now made in various sizes from i 200 HP, being direct-connected to dynamos, as shown in Fig. 580. They are also direct-connected to centrifugal pumps, hoists as well as air-compressors. The compression of the air is generated in the crank-chamber and the air is drawn into the cylinder at a slight pressure dur- ing each outstroke of the piston. The exhaust open- ing is automatically uncovered by the piston, the ex- haust passage being made in the cylinder wall. As the FIG. 75c. (To face p. 180.) VARIOUS ENGINES DESCRIBED. l8l piston travels toward the end of the stroke, this passage is uncovered, and the products of combustion are free to pass to the exhaust-pipe, while the Indicator diagram taken from the Mietz & Weiss Engine: diameter of cylinder, 12"; stroke, 12"; revolutions per minute, 300; scale, 100; B. H. P., 20. piston travels to the end of the stroke and the first part of the return stroke until the port is again covered, when the compression period commences for the next explosion. Consequently no valves are necessary, the air inlet to the cylinder being controlled by the action of the piston only, which simplifies the action of the engine. l82 OIL ENGINES. HORNSBY-AKROYD OIL ENGINE. Fig. 76 shows this engine as made by the De La Vergne Machine Company, of New York. It is also made by the patentees at Grantham, England, and in France and Germany.- The Hornsby-Ackroyd engine is made in sizes of i^ to 500 H. P., all sizes being made of the horizontal type. This engine as made by the English makers is shown at Fig. 77. The fuel oil-tank is placed in the base of the engine and the fuel is delivered to the va- porizer by the small pump actuated from the cam- shaft by the lever which also actuates the air-inlet valve. The oil supply is raised to the vaporizer valve- box in regular quantities, but the oil is only allowed to enter the vaporizer to the required amount, the re- mainder of the oil flowing back to the tank through the by-pass valve which is regulated by the governor. Thus, if the speed of the fly-wheel exceeds the normal number of revolutions for which the engine is set, the governor mechanism opens the by-pass oil-valve, allow- ing part of the oil to flow back to the oil-tank, and ac- cordingly reduces the charge entering the vaporizer, and consequently the mean pressure for one or more explosions is reduced in the cylinder. The governor is of the Porter type, actuated by gearing from the cam- shaft. The method of vaporizing and igniting is fully described in Chapter I. Both air-inlet and exhaust VARIOUS ENGINES DESCRIBED. 183 valves are actuated from the cam-shaft, these valves FIG. 770. being placed on the side of the engine. The air inlet in this type is different from the other engines de- 184 OIL ENGINES. scribed. In this case the air enters not through the va- porizer, but by means of separate valve-chamber. Diagram taken from Hornsby-Akroyd Engine : M. E. P., 48 Ibs. ; compression pressure, 50 Ibs. ; maximum pressure, 160 Ibs. ; revolutions per minute, 185 ; cylinder, 18.5" diameter; 24" stroke; full load. Diagram taken from Hornsby-Akroyd Engine: Diameter of cylinder, n"; stroke, 15"; M. E. P., 49.5 Ibs.; compression pressure, 60 Ibs.; revolutions per minute, 230; consump- tion of oil W. W., 150 F. 0.8 Ibs. per B. H. P. per hour. VARIOUS ENGINES DESCRIBED. 185 A two-cycle vertical high speed engine is shown at Fig- 77a, made and patented by the De La Vergne Ma- chine Company. This engine operates on the two- cycle plan, as explained on page 17. The features peculiar to this engine are the vaporizer, which is illustrated Fig. 770, at V, and the sprayer, which is shown at N. This sprayer is also shown at Fig. 70, and described on page 13. As will be seen from Fig. 770, the vaporizer is made of a conical shape and the oil is injected directly into it. The compression of the air before explosion takes place in the crank-case and enters the cylinder at pass- age A. There being no contracted opening to the va- porizer, and as a compression pressure of 100 Ibs. is used, the clearance in the combustion space is very small and all the air entering the cylinder is forced into the vaporizer, where it freely mingles with the fuel. A baffle plate placed on the piston deflects the air into the vaporizer and a slight scavenging effect is pro- duced, which forces the exhaust gases from the ^com- bustion chamber. The exhaust opening is shown at E. The engine runs at approximately 500 R. P. M. and is specially adapted for direct connection to electric generators. The governor is shown in detail at Fig. 246, and is of the centrifugal type placed in the fly-wheel, and is arranged to operate directly on the oil supply pump. The indicator cards are shown at Fig. 77&, that at A being from the power cylinder at fuel load, and that at B taken from the crank chamber. 1 86 OIL ENGINES. This engine is made in sizes up to 25 H. P. of the twin cylinder type. The bearings of the larger sizes are water-jacketed to insure maintenance of low tem- perature and allow free lubrication. Oiling of all bear- ings is effected by means of a force feed oil pump. i -r 4-2 - Aim r FIG. 77&. VARIOUS ENGINES DESCRIBED. i8 7 The vertical type Hornsby-Akroyd engine, which was previously built, is also shown here in sec- tion (Figs. 78 and 79). The cam-shaft is operated i88 OIL ENGINES. by a gearing from the crank-shaft in the regular way, the valves being operated by levers and rods. As will be seen from the illustration, the cylinders are built separately, being water- jacketed and mounted on a FIG. 79- cast-iron frame of the enclosed type containing the crank-shaft. Lubrication is effected from the splash- ing of the crank in a bath of oil. The 15 H. P. engine has cylinders &j" diameter by 9" stroke. The governing is effected by regulating the length of the stroke of the oil pump; no adjustment of the pump is therefore necessary. The governor is of the Rites pat- VARIOUS ENGINES DESCRIBED. 189 ent type, and a regulation of less than 2 per cent is claimed by the makers of this engine, with a variation of the load within the engine's limits. THE RITES GOVERNOR. An illustration of the Rites governor is shown at Fig. 80. It will be seen that it is placed in the fly- FIG. 80. wheel in the usual way with this type of governor. The Rites governor has now become so widely known that only a short description is necessary. Briefly, it consists of but a single weight, distributed on opposite sides of the shaft with a spring connection to balance centrifugal force. In its application to the oil or gas igO OIL ENGINES. engine an eccentric cast in one piece with the weight structure is provided. The movement (while in op- eration) of the governor weight consequent upon any change in speed of the crank-shaft is transmitted to the regulating device by means of the eccentric attached to the governor weight, on which are fitted eccentric straps and rod. The other end of this eccentric rod is attached to a lever, which reciprocates the shaft on which is placed the eccentric fulcrum controlling the stroke of the plunger of the oil-supply pump or the opening of the gas valve. The operation is as follows : If the speed of the crank-shaft is increased by a fraction beyond the re- quired maximum speed, the momentum of the weight overcomes the strength of the spring, thus changing the throw of the eccentrics, which in turn reduces the length of the oil-pump stroke. Among the many claims for the Rites governor are the following: It allows of a large range of adjust- ment. It is remarkably quick in action, and the distri- bution of the governor weights on each side of the weight-pin and also on each side of the crank- shaft allows the governor strength to be greatly increased without necessarily increasing the centrifu- gal element correspondingly, and utilizes the inertia action of the governor most effectively for extreme changes of load. There is only one bearing requiring lubrication namely, that of the fulcrum pin. No dash- pot is required, and only a small brake or drag is used to steady the movement of the governor weight. The speed of the engine is altered by the adjustment VARIOUS ENGINES DESCRIBED. 19! of the spiral spring controlling the weights. Speed is increased by moving the pin holding spring outwards from the fulcrum pin and at the same time correspond- ingly increasing the tension of the spring, to preserve a constant proportional initial tension corresponding to the change of leverage of the spring. To decrease speed, reverse the above operation, or, if desired, add to the weight, thus increasing its centrifu- gal force. To remedy racing, move the spring connection to the governor weight in its slot away from the weight-pin, leaving the tension of the spring unchanged. If it is required to regulate closer, reverse this movement of the pin in its slot ; that is, towards the weight-pin. LB. COM P. =95 MAX. 330 FIG. Sob. JOHNSTON OIL ENGINE. The Johnston oil engine is shown in Fig. 8oa. It is made in various sizes up to 200 H. P. of the vertical type with one or more cylinders. It operates on the four-cycle principle, the air inlet and exhaust valves being actuated from a cam-shaft placed outside the crank casing operated by gearing from the crank-shaft in the usual way. 192 OIL ENGINES. The chief feature of this engine is the method of ig- nition, which is effected by means of a hot surface, being a hot plate on the end of the piston, which is maintained at the proper temperature by the heat of combustion, and is insulated from the piston itself. (See Fig. 9.) As will be seen from the indicator card at Fig. 806. the compression pressure is approximately 100 Ibs. per square inch, and the maximum pressure 300 Ibs. The injection of the fuel takes place after compres- sion is completed, that is, at the end of the inward stroke. A small air compressor attached to the crank-shaft furnishes the air necessary for spraying the fuel into the cylinder. The same compressor also furnishes the compressed air necessary for starting the engine. In starting, a metal thimble placed in the combustion cham- ber is heated by an external torch. An electric ignitor is used in some cases instead of the heated thimble for starting. The makers of this engine claim a fuel consumption of three-fifths of a pound of fuel or crude oil per actual B. H. P. per hour. THE BRITANNIA Co/s OIL ENGINE. An engine fully described in the Engineer* (Lon- don), made by the Britannia Co., of Colchester, Eng- land, is shown at Figs. 81, 82 and 83. It will be seen from the illustrations that it is of simple design. The vaporizer is a modification of the type as shown at Fig. 2 and referred to on page 8. The oil is stored in the base of the engine and is raised to the vaporizer by the suction of the piston. Consequently no oil pump is required. The air inlet valve C is automatic, *See Engineer and Engineering, London, of June 19, 1003. VARIOUS ENGINES DESCRIBED. 193 and is placed on the side of the engine above the ex- haust valve D. The governor is of the centrifugal type and operates on the "hit-and-miss" principle, and is arranged to control the vapor inlet valve. On starting the engine the vaporizer is heated by external lamp for a few minutes and a small amount of fuel is injected into the vaporizer by means of the filling cup, marked E. The vaporizer consists of a flat cast-iron box, marked A, provided with baffle plates, which cause the oil or vapor to travel backwards and forwards FIG. 82. FIG. 83. The through passages before entering the cylinder, ignition is caused by means of tube B. In operation the oil is raised to the vaporizer from the tank by the vacuum in the cylinder, caused by the outstroke of the piston. The cylinder communicates with the vaporizer through the vapor inlet valve only. Air enters both through the main air inlet valve C, Fig. 81, and a passage communicating with the vaporizer. The air entering can be throttled so that proportions of air entering by alternative ways can be regulated IQ4 IL ENGINES. as required. The oil supply enters by the passage closed by means of sleeve e, which forms also a valve as shown in Fig. 83. When the sleeve moves, due to the vacuum in the cylinder, by piston movement, oil is drawn (through .holes in the sleeVe) into the vaporizer. The amount of oil entering depends on the amount of air allowed to enter the cylinder through the vaporizer. When due to the action of the governor, the vapor valve remains closed, no communication is made with the cylinder and no oil enters the vaporizer. Two passages between the vaporizer valve and the cylinder are made, in one of which is the igniter-plug, which is simply a piece of steel having projecting internal ribs which absorb the heat from explosion, becoming red- hot in operation. No exhaust gases pass through the igniter, and on light loads gases only enter the igniter preceding an explosion. The temperature of igniter and vaporizer is easily maintained, and no stoppage due to the cooling of the vaporizer can occur. AMERICAN OIL ENGINE Co.'s ENGINE. A vertical type oil engine made by the American Oil Engine Co., suitable for industrial and marine pur- poses, is shown in the single and twin-cylinder type at Fig. 84 and in section at Fig. 85. It is of the two- cycle type, the compression of the air previous to ignition being effected in the crank chamber, from whence it passes by a passage and port uncovered by the piston as it moves forward, to the cylinder. The fuel is supplied by oil pump operated by cam and VARIOUS ENGINES DESCRIBED. 195 placed close to the sprayer shown in Fig. 85. The .governing is effected, by means of a sliding cam which FIG. 84. actuates the oil supply pump and shortens or lengthens the stroke of the pump in accordance with the load. 196 OIL ENGINES. The ignition of the charge is caused by the heat of a steel disc on to which the fuel is sprayed. Starting is effected either with an electric igniter or by means of ELECTRIC IGN FOR STARTING WITH GASOLINE FIG. 85. tube heated externally by kerosene torch. Gasoline or alcohol is used instead of kerosene for starting when the electric igniter is operated. A multiple force feed VARIOUS ENGINES DESCRIBED. IQ/ oil pump furnishes lubrication to the cylinder and all bearings. This engine is made in various sizes from i^ H. P. upwards. THE BARKER ENGINE. A type of engine which in recent years has received some attention from inventors is that in which the cyl- inders revolve around a fixed crank-pin or cam. For situations where space is limited and where vibration should be eliminated and weight per horse power re- Fin. 86. duced to a minimum, the advantages of this type of engine are apparent. Fig. 86 shows the engine complete. It will be noted that there is no fly-wheel, the cylinders themselves 198 OIL ENGINES. revolving around the centre bearing and furnishing the necessary momentum. The engine works on the "Otto," or four-cycle ; that is, each cycle of operation in each cylinder consists of four strokes ; thus a four- cylinder engine has four impulses each revolution. This is effected by the use of the cam motion shown in Fig. FIG. 87. FIG. 88. 87, instead of the ordinary crank. This mechanism is equivalent to a double-throw crank. Fig. 88 shows the four pistons in position, the cyl- inders having been removed. The air and vapor inlet to the cylinders and the exhaust outlet are effected through the hollow spin- dle on which the cylinders revolve, radial ports or pas- sage-ways being made in the spindle, which are un- covered by recesses in the cylinders, as these recesses coincide with the ports of the cylinder at each revolu- tion. The ignition is caused by electric igniter of the jump- spark type. The timing of the ignition is obtained by VARIOUS ENGINES DESCRIBED. IQ9 a revolving contact breaker. When using gasoline, a carburetor of the ordinary float type is attached. When kerosene is used as fuel, a vaporizer somewhat similar to that shown at Fig. 3 is used, the heat from the exhaust gases being sufficient to maintain the re- quired temperature for vaporization. The oil is fed by gravity and the vapor is drawn into the cylinder by the piston displacement in the usual way. The power is taken off from a pulley attached to the sides of the cylinder. A motor of this type of one actual horse-power weighs about 15 Ibs. ; a 3 H. P. weighs approximately 35 pounds. A speed of about 800 R. P. M. is obtained, which speed is varied by the lead given to the igniter. When running at a high speed the engine can be held in the hands without vibration. CHAPTER XI. PORTABLE ENGINES. PORTABLE type oil engines, made by nearly all mak- ers of fixed horizontal engines, are used for various purposes. Such engines combined with air compressors are very useful for operating pneumatic tools used in structural iron work, repairs and similar work where compressed air is required in different locations for short periods of time. For portable elec- tric-lighting purposes the oil engine (Fig. 89) is well adapted. Electric lighting outfits of this kind have been found useful for operating search-lights for mili- tary purposes and for supplying current for electric lighting for contractors, etc., where illumination of a portable nature is required for a short period only. The portable oil engine is also largely used for farm work, such as operating threshing machines, etc. In all cases these engines are required to be frequent- ly removed from place to place, and therefore must be as light as possible in design, but must be of such substantial construction that they can be trans- ported from place to place over rough, uneven roads, and all provision for operation in the open air must be made. In Europe the portable engine is generally con- structed somewhat differently to the ordinary fixed PORTABLE ENGINES. 2OI engine. The heavy cast-iron bed-plats used in fixed engines is replaced with light steel construction, which considerably reduces the weight. This type of con- struction is shown in Fig. 89, and while it is somewhat more expensive than those portable engines composed of the fixed engine without base-plate bolted to steel or wooden truck, the advantage of lightness is gained as well as facility in transportation. In the United States the portable engines are more generally composed of the standard fixed engine placed on steel or timber truck. This outfit is cheaper in cost than that of the special construction above men- tioned. The portable engine is often required to operate in localities where running water is not available, and therefore it must be self-contained as regards the cool- ing of the cylinder. An important feature of this out- fit is, therefore, the cooling-water apparatus. In order that only a small amount of water may be used, dif- ferent devices have been constructed for rapidly cool- ing a small amount of water. Such device in the Hornsby-Akroyd consists of a gradirwork placed in- side the circular chamber, seen in Fig. 89, placed in the front of the engine. The water is circulated around the cylinder of the engine by a small recip- rocating pump operated from the cam-shaft, and after passing through the cylinder and taking up the heat is delivered to the upper part of this chamber and flows down a wooden gradirwork. A draft of air is at the same time induced by the exhaust emitted above, which 202 OIL ENGINES. rapidly cools the water as it trickles down the slats of the gradirwork. For a 20 H. P. engine only about 30 to 40 gallons of water are required. Another device for cooling the water is that com- posed of trays over which the water flows while a FIG. 90. draft of air is induced in the same way as above men- tioned. An engine equipped with this cooling device is shown in Fig. 90, as made by Crossley Bros., Man- chester, England. Another type of portable engine is that shown in Fig. 91, consisting of the Mietz & Weiss engine. This PORTABLE ENGINES. 2O3 is the standard fixed engine placed on a truck, the cool- ing water being supplied from a tank in front of the engine. As the internal combustion engine cannot be bal- anced as effectually as the steam engine, greater vibra- tion of the engine has to be overcome in holding it in place. An important feature of the portable engine, therefore, is the chocking device which is required to hold it rigidly in position when in operation. In some engines simply a wooden chock is used, placed each side of the wheel and drawn together, holding the wheels from moving. A very effective device is that composed of four adjustable struts, each having turnbuckle fitting 204 OIL ENGINES. into a flat timber plank placed on the ground length- wise under the engine and protruding from each end. When it is desired to hold the engine in position, the struts, placed at each end of truck, are length- ened by means of the turnbuckle, thus taking the PORTABLE I-:.\(,I.M:S. "205 weight off the wheels. By this means the engine is held as rigidly as when on a concrete foundation, and without movement. When it is required to remove the engine the struts are shortened by simply unscrewing until the weight is taken up by the wheels. The wear on the wheels due to the continuous vibration of the engine is thus avoided, and the wheels can consequent- ly be lighter in construction. A portable air-compressing outfit is shown in Fig. 92. As will be seen from the illustration, it is composed of the oil engine, which operates the air- compressor by a gearing, the air receiver being placed beneath the frame of the truck, while the cooling-water device is placed lengthwise with the air compressor. An oil traction engine is shown at Figure c)2a, in which the ordinary frame and truck of the steam trac- tion engine is used, the boiler being replaced by an oil engine. The engine shown in the illustration has two cylin- ders placed at an angle to each other, the connecting rods operating on one crank-pin, the power from the crank-shaft being transmitted by gearing to the road- wheels. The cooling of the water is effected somewhat similarly as with the portable engine. This type of engine, made by Messrs. R. Hornsby & Sons, Grantham, England, after very severe tests recently received a first prize of 1,000 from the British War Department. CHAPTER XII. LARGE-SIZED ENGINES. THE higher thermal efficiency of the gas engine as compared with that of the steam engine and its adap- tability to use the poorer and cheaply produced gases made in the producer plant, the Mond gas plant, as well as the gases given off from blast furnaces, etc., has re- sulted in its development and manufacture in units as high as 5000 H. P. The "oil gas" producer, an apparatus for furnishing gas produced from vegetable and mineral oils, is also used in connection with the gas engine ; and also, as described hereafter, the apparatus developed by C. C. Moore & Co., of San Francisco, for generating gas from crude oil, which gases are furnished to the gas engine. Until recently the oil engine self-con- tained, that is, requiring no outside gas-making appa- ratus, of 100 H. P. was probably the largest unit made. The oil engine up to 500 H. P. is now, however, being manufactured. The production of great quantities of petroleum in Texas and California chiefly useful for fuel purposes only, and which can be procured at a low price as com- pared with illuminating oils, has enabled the oil engine in many locations to compete in cost of installation and LARGE-SIZED ENGINES. 2O7 operation with gas engines using producer and other cheap gas. With the smaller size oil engines simplicity of con- struction is probably the most important feature, as it must be adapted for successful operation in the hands of unskilled attendants and be free from all delicate mechanisms which may require skilled attention. With the larger size engines, which have a greater earning capacity and which allow of the expense of a skilled attendant, simplicity of construction is not so important a feature. Mechanisms which may frequently give trouble in the smaller engines when in the hands of unskilled and inexperienced attendants may in the hands of the engineer attending to the larger engines give continuous satisfaction. The tendency in design of the larger size gas en- gines is resorting to the two-cycle method of operation. Where the four-cycle method is adhered to two or more cylinders are employed. The four-cycle single- cylinder engine, as already explained in Chapter L, obtains an impulse once in two revolutions, and consequently during the three idle strokes of the piston the power and speed must be maintained by the mo- mentum of the fly-wheels, necessarily enormous in an engine of 100 H. P. or over for the power obtained, in comparison with the fly-wheel of a steam engine of the same capacity. With the two-cycle engine, in which an impulse is obtained each revolution of the crank-shaft, double the power is developed as compared with the four-cycle engine of the same size. The me- chanical efficiency is increased, owing to the reduced 2C>8 OIL ENGINES. weight of the fly-wheels, and the weight and cost of the engine per H. P. is curtailed. The difficulty of procuring proper combustion in the two-cycle oil engine, more essential where crude oil is used than where gas or gasoline is the fuel, is not yet entirely overcome. It has been previously stated that the larger size oil engines, to compete with the gas engine in cost of fuel, can do so only when a cheap grade of oil is used as fuel. To use such fuel, it is imperative that proper combustion takes place in the cylinder. It is of interest to compare the relative cost of oper- ation of the steam engine, the gas engine and the oil engine of, say, 50, 100 and 200 H. P. As the cost of fuel varies in different localities according to the cost of transportation, etc., this cannot be done to suit all cases. The following table, however, shows the relative cost of installing and operating a steam, gas and oil engine plant of 50 to 200 H. P. The cost of the plant includes cost of land, building of engine and boiler house, foun- dations, smoke-stack, etc., and all auxiliary apparatus. The cost of producer plant, and the cost of oil storage tanks and cost of apparatus for handling fuel is also in- cluded. It will be noted that the cost of water supply has in each instance been neglected. This is done be- cause the amount of water required would be approx- imately the same with each type; possibly a saving in . favor of the oil and gas engine would in many instal- lations be effected. The figures must be modified to suit the actual cost of fuel in a locality differing from those given. The saving favorable to the gas-engine 5 wv s f ' 'Id ^ "^ ! 1 |l| -i W . OO " \O O O*^ N L* 1^ ^ w a * N ^ ioir> en co r^ H w O *5 en IPl OOO^O Q OO'cn ONOO^O O mr> TJ- | H 2 ? ?' Is ^ i- | 3 S M OO u c*-^r>- en xnm oo Slf T+- . . Q . . O co_go8- 2o N 4) o'| H ^tfl s !| f 8 i! ^?-}4 s a flit cc s = J2 3 os^>-o o go co QOUQ^^m r* Oco c> ake Horsepower. c I f l *"*" ; i ^8^3^5^1 ^ ^i .; : S . ^ w S 5 ^ K * S S3 o3 : u : ^ | UlX 8 -? ? ^s^: g>ii^S ^5.5 . 214.) LARGE-SIZED ENGINES. 215 of wedges and screws, as shown. The piston is made as long as possible, in order to give a maximum bear- ing surface, and is fitted with steel snap-rings. The connecting-rods are of the marine type, with adjus- table bearings at both ends. The valve motions are operated from the cam-shaft inside the enclosed frame, which is actuated by gearing from the crank-shaft. The engine operates on the "Otto," or four-cycle, prin- ciple. The air supply for supporting combustion is drawn into the cylinders through the air inlet valves placed in the housings to one side of the top of the cylinder head. (See Fig. 99.) The fuel to the cylinders is supplied by a separate oil pump for each cylinder. The oil pump is operated from a shaft geared to the cam-shaft. The method of operation is as follows: The engine is first started by means of compressed air, which is supplied from an auxiliary air receiver suitably connected to the cylinder by means of a start- ing valve operated by a starting cam, thrown into ac- tion by hand, before starting. By this means com- pressed air is admitted to the cylinder and the piston is moved forward for one or two revolutions. Simul- taneously compression of the air in the other cylinders takes place, which is sufficient to ignite the charge of oil in them. As soon as the ignitions take place the starting cam is automatically thrown out of action, the exhaust cam being simultaneously thrown into action. The admission valve for fuel and air under pressure is shown in Fig. 99. As will be seen, the valve spindle is surrounded by a series of brass wash- ers perforated with small holes, being parallel to the 2l6 OIL ENGINES. spindle. The fuel before entering the cylinder occu- pies the cavities in and between these washers as it is delivered from the fuel pump. Compressed air is in- troduced behind the oil inlet and at the opening of the FIG. 99. admission valve the oil is sprayed into the cylinder. The fuel enters the cylinder only after the compression stroke is completed and when the piston is beginning LARGE-SIZED ENGINES. 217 to descend. The compression in the cylinder caused by the previous up-stroke of the piston reaches a pressure of 450 to 525 Ibs. per square inch ; resulting temperature approaches 1000 Fahr., which is more than sufficient to ignite the oil vapor. The fuel valve remains open about one-tenth of the period of the ex- pansion stroke. The amount of fuel entering depends upon the action of the governor. Air in excess of that required to burn the fuel is introduced into the cylin- der, and accordingly perfect combustion takes place. The speed of the engine is controlled by means of the governor acting on the by-pass valves (one for each fuel pump). The by-pass oil valves are opened by arms pivoted on a shaft raised or lowered by the gov- ernor, and operate as follows : If only a small amount of fuel is required in the cylinder to overcome the load, the governor holds the by-pass valve open for a length- ened period and a greater amount of the oil is allowed to return to the suction pipe, while, if the load is greater, and consequently more fuel is required in the cylinder to overcome it, the by-pass valves open for a relatively shorter period and then less oil returns to the suction pipe, a greater amount of fuel passing to the cylinder. By this method of governing a very close regulation of speed is effected. Indicator card from this engine is shown at Fig. 100. The Diesel engine has created great interest in engineering circles the world over, and many tests have been made of it. Professor Denton, of the Stevens Institute, Hoboken, N. J., in 1898 conducted 2l8 OIL ENGINES. a series of tests on this engine, and according to his re- port of those tests the consumption of fuel was 0.534 Ibs. per B. H. P. per hour at full load, and at less than half load 0.72 Ibs. per B. H. P. per hour. This is FIG. 100. equivalent to a thermal efficiency (on the I. H. P.) of 37.7 per cent. The following is the heat-balance table as shown by Professor Denton : PER CENT. Heat of combustion accounted for by indicated power 37.2 Removed by jacket 35.4 Remainder 27.4 Total heat of combustion 100.0 Another type of the Diesel engine, that made by the manufacturers in Sweden, is shown at Fig. 101. The following tests were made by Prof. Meyer in 1900 on a German type 30 H. P. engine. The LARGE-SIZED ENGINES. 219 cylinder 11.8" diam., 18.1" stroke, air-pump cylinder 1.9" diam., 3.1" stroke. Air was taken from motor cylinder at a pressure of 20 atmospheres and com- pressed to 45 or 60 atmospheres. Negative work in the motor cylinder was equivalent to 5.66 H. P. at 181. OIL ENGINES. R. P. M. The air pump was not indicated, consequently the effective power is not given. The mean indicated pressure at normal load was approximately 90 Ibs. per square inch. The exhaust gases were invisible. Two kinds of fuel were used, American petroleum, specific gravity 0.79, having 18,540 B. T. U. per lb., and Tegern See (Bavaria) crude oil, specific gravity 0.789.* TABLE VIII. RESULTS OP TRIALS OP A DIESEL OIL ENGINE (MEYER), 1900. American Petroleum. Raw Tegern See Oil. Load on Brake. Full Load. Nor- mal. % Load. Half Load. Nor- mal. H Load. Half Load. Revs, per minute .... Brake (or actual) H. P., metric Indicated H. P. (mo- tor cyl.) 177-4 39-45 48.2 82 0.48 28 181.1 30.17 39-52 76 o-45 30 184.0 23.81 33-io 72 0.48 28 183-3 15-26 25.02 61 o-57 24 l8l.2 30.18 40.96 73 0.47 29.8 181.8 23-5 33-0 7i 0.49 185.0 15-4 26.4 58 0.57 Mech. efficiency Oil used per B. H. P., per hour Ibs. Percentage of heat ) of oil as useful > work ) CRUDE OIL VAPORIZER. On the Pacific Coast crude oil is now being largely used for fuel. In many instances this fuel is used, be- ing vaporized or gasified in a separate apparatus and is then consumed in the ordinary gas engine. This *"Gas and Petroleum Engines." By Prof. Wm. Robinson. Second edition. Page 777. LARGE-SIZED ENGINES. 221 apparatus is separate from the engine, the oil being entirely gasified before it reaches the engine cylinder. Such vaporizing apparatus or retorts are made by vari- ous manufacturers, but in general principle they are similar. The heat of the exhaust gases from the engine is utilized to heat the retort into which the oil is introduced, where it is gasified. Mr. Frank H. Bates has drawn attention to these various retorts, which usually consist of a cast-iron chamber enclosing an inner chamber, also of cast iron.* The fuel to be gasified enters the inner ribbed chamber through suitable openings, and the gas is drawn from the chamber through a separate connection from the inner chamber to the engine cylinder. The exhaust gases from the engine are connected to the outer cham- ber and pass around, heating the inner chamber to a temperature necessary for vaporization. Provision is made to draw off the residue of the crude oil, which is not capable of vaporization, and provision is also made to cleanse the vaporizing chamber of deposit of carbon and other solid matter. In the "Economist" retort the inner ribbed chamber, or drum, is made to slowly revolve,, and, the ribs be- ing spirally shaped, the oil is propelled from end to end and the heat is then equally distributed around the inner chamber. In service where the load is fairly constant, and where opportunity to cleanse the retort occasionally, is afforded, these retorts have given ex- cellent results. For installations, however, such as *See Journal of Electricity, Power and Gas, Vol. XIII., P- 5- 222 OIL ENGINES. electric railway service, or where the load varies be- tween wide limits and where continuous running is imperative, it is stated that difficulty has been experi- FIG. 102. enced, due to the fluctuating temperature of the retort heated by the exhaust gases, which involves improp- erly regulated supply of vapor to the cylinder. To overcome this difficulty with varying loads, Messrs. C. C. Moore & Co. have developed an improved sys- tem of using crude oil in connection with gas engines. FIG. 103. The generator, as made by this company, is shown in Figs. 102 and 103, in which are shown a longitudinal elevation of the generator, end elevation, and also the LARGE-SIZED ENGINES. 223 generator connected up to- its drainage chamber for the automatic removal of the deposit. It will be noted from Fig. 102 that a scraper is arranged which can be moved from end to end of the vaporizer by means of the hand wheel. This scraper is shown in Fig. 105. The oil supply is regulated by means of a thermostatic valve, and is automatically maintained at a constant level by this means. The method of operation is as follows : Oil is first fed into the vaporizing chamber by means of a valve until the level in both tlTis chamber and in the oil feed device is a little above the level of the upper drain pipe. A heating device is then inserted into the exhaust gas passage, heating the vaporizing chamber to about 300 Fahr. The engine is started by means of compressed air, and when in operation air heavily charged with oil vapor passes through the nozzle G, Fig. 102, to the engine cylinder. The exhaust gases from the engine afterwards furnish the heat necessary to maintain the vaporizer at a proper temperature ; these gases' pass around the generator, and thence by the exhaust pipe to the roof. The tem- perature of this chamber is regulated by the thermo- static valve, which, when the temperature of the vapor- izer rises too high, allows the exhaust gases to be by- passed from the vaporizer and pass directly to the roof. The thermostatic device consists of an alumi- num tube inserted directly into the vapor chamber, around which the exhaust gases pass. The aluminum tube is closed at its upper end and is attached to a sys- tem of levers so arranged as to exaggerate its move- 224 OIL ENGINES. ment, caused by the variation in temperature. Ac- cordingly, when the temperature of the vaporizer chamber rises above that required, the expansion of the aluminum tube is arranged to close a needle valve, which allows the pressure of the exhaust gases from the engine to lift a larger valve, thus opening a pas- sage outside the vaporizer, through which the ex- haust passes instead of entering the chamber around the vaporizing retort. By this means the tempera- ture of the retort is regulated within very close limits. FIG. 105. The proper level of the liquid fuel to be vaporized is regulated by an automatic ball check valve placed in the chamber marked /, Fig. 106, through which the oil passes to the vaporizer. A relief valve is in- serted in the supply pump, so that when the valve to the vaporizing chamber is closed the fuel can by this means flow back to the tank. The retort is readily cleansed by means of the scraper already referred to, shown in Fig. 105, which is operated by hand period- ically. In the larger size installations made by Messrs. C. C. Moore & Co. more extensive equipment is provided, in which arrangement is made to utilize the heat rejected by the exhaust gases and also (To face p. 224.) LARGE-SIZED ENGINES. 225 the heat given off from the water jacket, and in which installations the residue of the oil is partly used also. In these outfits a combination of oil vapor and water gas is formed, two superheaters being added, one of which is heated by the exhaust gases, in which part of the cooling .water issuing from the water jacket is turned into steam ; the second superheater is heated by the burning of residue oil in connection with com- pressed air. In this way, it is stated, steam raised to approximately 1600 Fahr. in the chamber C, Fig. 106, is mingled with the oil vapor forming the combi- nation of oil vapor and water gas referred to. By the use of this apparatus a greater economy is effected and a greater part of the heat of the fuel utilized. The following is a brief description of the accom- panying illustrations, Fig. 106: The three-cylinder Westinghouse gas engine of the vertical type is shown at A. The generator by which the crude oil is vaporized is shown at B. The super- heater (heated by residual oil burners) is marked C. The chamber for drainage of residuals is shown at D. H is an air-compressor operated by belt from the en- gine crank-shaft. 7 is the automatic oil feed, which maintains the proper level of the oil in the generator. E, E 1 and E 2 are the air storage tanks maintained at a pressure of 160 Ibs. per square inch. F is the rotary oil pump which raises the fuel from the storage tank underground to the vaporizer. The water-cir- culating pump which supplies the cooling water to the cylinders is shown at G. A separate vaporizing attachment for using crude 226 OIL ENGINES. oil of the type already mentioned is shown at Fig. 108. The vaporizer is separate from the engine, being at- tached to the gas or gasoline engine, where it is re- quired to use crude oil as fuel instead of gas or gaso- line. The outfit shown is the Fairbanks-Morse gas or gasoline engine, which has attached to it the outside apparatus for vaporizing the oil. the vaporizer being a cast-iron chamber into which the liquid oil is injected. This chamber is heated while in operation by the ex- haust gases. Before starting it is necessary to use an outside lamp, in order that the chamber may become heated to the temperature required to vaporize the fuel. The oil is mixed with air drawn into the vaporizer and becomes vaporized in this chamber, and is drawn there- from into the cylinder in the usual way. As will be seen from the illustration, the engine shown at Fig. 108 is geared directly up to hoisting drum. These outfits are very largely used for mining and similar purposes, where hoisting engines can be readily utilized. A new type of oil engine, made in sizes from 85 H. P. upwards, is shown at Fig. 109. This engine is manufactured and patented by the De La Vergne Ma- chine Company and is known as their Type FH oil engine. It operates on the four-cycle principle, and is single acting, of the horizontal type, and is furnished in either single or twin cylinder units. The largest size which this company has furnished hitherto is 250 H. P. twin cylinder, but engines of larger size are in course of construction. r LARGE-SIZED ENGINES. 22/ This engine is equipped with a two-stage air com- pressor shown in the sectional view at Fig. 109, which is operated directly from the crank-shaft by an eccentric. The compressed air is used for spraying purposes and is injected into the vaporizer and combustion space with the fuel, thus insuring complete spraying of the fuel as it enters the vaporizer. Briefly stated, the method of operation of this engine is as follows : At the first stroke of the piston outwards, air is drawn into the cylinder through an inlet valve on the top of the breech end or valve chamber. On the sec- ond or inward stroke of the piston, compression takes place. As will be seen from the indicator card at Fig. 112 the maximum pressure of compression is 260 Ibs. As the process of compression is completed the fuel (fuel or crude oil as heavy as 14 Beaume) is in- jected into the vaporizer and mingles with the com- pressed air already referred to. The spray valve shown in section Fig. 70 is posi- tively controlled by an independent cam on the cam- shaft. The compressed air furnished by the two-stage air compressor is delivered at the sprayer at about 400 Ibs. pressure. Only a small amount of air (about 2% of the cylinder volume) is delivered at each injection. Immediately the fuel enters the combustion space and comes in contact with the air heated by the process of compression together with the heated walls of the vaporizing chamber ignition takes place, and on the third or outward stroke of the piston expansion begins. The maximum pressure, as will be seen from the indi- cator card, is slightly over 400 Ibs. At a point 85% of 228 OIL ENGINES. the stroke, the exhaust valve is opened, allowing the products of combustion to escape. The vaporizer of this engine is a rough gun-iron cast- ing, somewhat similar to that of Type 2 described on page 8, but without contracted opening. The oil pump is operated from the cam-shaft and has the length of its stroke varied by the governor in accordance with the load requirements. ttSSYJSt OIL COMSUMPTlON OP 20 x34.'/ 2 TyPE FH OIL. DELRVERSME FUEL OIL. BEUTED TO IOO D.C.GeiNEfvrrOR CflRO EL..CO .__ -"^~ ^* H> La '/A Vz %. Vl OF FULL I-OBD FIG in. This engine is of the best design in every detail and of very heavy construction. The marked economy is shown by diagram, Fig. in, from which it will be seen that a fuel consumption as low as 0.393 ^- of crude oil per actual horse-power per hour has been obtained. Tests have also shown the fuel economy to be as low as 0.437 H>. at half load. (See page 248.) The cams operating the air and exhaust valves are LARGE-SIZED ENGINES. 229 accurately designed and machined. The engine is al- most silent in operation. The starting is effected in the ordinary way by means of compressed air, as explained on page 105. The vaporizing chamber is heated for a few minutes before starting by means of an external lamp in a similar way as with Type 2 engines (page 8). The regulation of speed is effected by a Hartung governor operated by gears from the cam-shaft, which actuates through levers directly on the oil supply pump, lengthening or shortening the stroke in accordance with the requirements of the load. At this time only a few installations of this engine have been made, but the makers state that under con- tinued and exhaustive tests made by independent en- gineers results even better than those shown in the ac- companying diagram have been obtained. OIL. EINGIME T>PE F H >D CflRD HEP 100 IBS PER 3Q. IN FIG. 112. ' CHAPTER XIII. FUELS. THE fuel to be used in the type of engines here dis- cussed is frequently a matter of inquiry, and ac- cordingly a brief description of the various fuels used is given. The Texas oil, which hitherto has not been so fully treated of elsewhere is discussed more fully than the other fuels. The supply of petroleum is produced chiefly in the United States of America and in Russia, while it is also found in many other countries in small quantities. Petroleum is found in the United States in the Cen- tral Eastern States, notably Pennsylvania, New York, Ohio and West Virginia ; in Texas in the region around Beaumont and Corsicana, in California chiefly in the Kern County, Coalinga, Los Angeles, pro- ducing fields. In Russia oil fields are found around Baku and in the range of the Caucasus Mountains. Paraffin or shale oil, a fuel produced by a slow proc- ess of distillation of "shale" and bituminous coal, is also produced in Scotland. Crude petroleum as it issues or is pumped from the earth contains a variety of hydrocarbons of different characteristics, and after its sediment has settled it is FUELS. 2 3 I subjected to a process of refining known as fractional distillation, by which process the various hydrocarbons are separated and are afterwards condensed into the dif- ferent products known in commerce as benzine, gaso- line, naphtha, being the lighter products, having a flash- point below 73 Fahr. Next the illuminating oils, such as W. W. 150 kerosene, White Rose and other brands of a similar composition, are obtained, having a flash- point above 73 Fahr. The next product is gas oil, or fuel oil, used largely for gas-making and also as fuel in internal combustion engines, having a flash-point of about 190. Lubricating oils, paraffin, wax, vaseline, etc., are afterwards procured, the residue being only a heavy liquid sometimes used for fuel. The fuels used chiefly in the engines here discussed, as already stated, are the crude oils, the illuminating oils and the fuel or gas oil. CRUDE OILS. In the accompanying tables will be found the char- acteristics of the crude oils produced from the different Russian oil fields, the American oil fields of the Alle- gheny region, as well as the oils produced in Texas, California and elsewhere. The Russian crude oil is heavier than the American product found in the Allegheny region, the average specific gravity of the former being .85, that of the lat- ter being .79. Texas crude oil, many samples of which have been used by the writer in the Hornsby-Akroyd oil engine, 232 OIL ENGINES. is a dark, heavy liquid having a specific gravity vary- ing from .861 to .915, the flash-point (open method) be- ing 180 to 195. An analysis of this oil by Messrs. Clifford Richard- son and E. C. Wallace,* taken from the Lucas well, Beaumont, Texas, 1901, in which the following, it may be mentioned, were the methods of examination, has been made. The specific gravity was determined in a picnometer at 25 C., the flash-point was taken in a New York State oil tester, the refractive index with an Abbe re- fractometer at 25 C. The viscosity represents the number of seconds required for the oils to flow from a loo c.c. pipette, according to the P. R. R. specifica- tions. Volatility was obtained by allowing 20 grm. of crude petroleum to be heated in an open dish 2\ inches diameter, \\ inches deep, to various tempera- tures for various periods of time, or until the loss be- came small enough to neglect. The volatilization then goes on below the boiling point. The vapor not being confined, there is no "cracking." The distillation in Engler's Flask was carried out in the usual way, the distillate between 150 and 300 C. representing the burning oil available commercially. For the purpose of fractional distillation, about half a litre of oil was distilled in a litre flask of the Engler shape (but larger) supported on a six-mesh iron cloth surrounded by loose bricks covered with asbestos board. The distillate was condensed in an air-con- *See "Journal of the Society of Chemical Industry," Vol. 20, No. 7. FUELS. 233 denser 3 feet long connected with a Bruhl's receiver, where a vacuum of 20 mm. could be maintained. All joints were mercury sealed or of solid glass ; access of air or decomposition was prevented. A current of carbon dioxide was conducted to the bottom of the distilling flask to agitate the oil and remove air from the appa- ratus. The oil was heated by a ring-flame Fletcher burner, and distilled at ordinary pressure as long as there were no signs of cracking. As soon as any de- composition was recognized, or the temperature had reached a high figure, the oil was cooled and the vacuum made. The difference in boiling point at at- mospheric pressure and at 20 mm. for hydrocarbons, boiling under 760 mm. at about 320 C., is 117, a distillate coming over at 317 at atmospheric pressure beginning to distil at 200 in a vacuum of 20 mm. The distillates were then treated twice with an excess of sulphuric acid, washed with dilute soda, dried over sodium, and then determinations repeated. Finally, one of the distillates was treated with a mixture of equal volumes of sulphuric and nitric acid, washed, boiled with sodium and examined. EXAMINATION OF RESIDUES. The residues left after evaporation in the open dish, or from either of the methods of distillation, are characteristic and of value in determining the nature of any petroleum, and as to whether it has a so-called asphaltic or paraffin base. ULTIMATE ANALYSES. These were made with the precautions which have been found necessary in burn- ing the polymethylene hydrocarbons, which very read- ily escape complete combustion. 234 OIL ENGINES. Beaumont oil contains a much larger proportion of unsaturated hydrocarbons removable by sulphuric acid than either Pennsylvania or Ohio petroleum. The Beaumont oil has a high sulphur content and carries, as it comes from the wells, a large amount of hydro- gen sulphide in solution. This gas has previously been observed in solution in petroleum, but not in so large quantity as at Beaumont. The sulphuretted hydrogen is largely lost on standing, and more completely on blowing air through it. After such treatment the oil contained 1.75 per cent, of sulphur in the form of sul- phur derivatives of the hydrocarbons. A comparison of the ultimate compositions of the Texas oil with other oils used for fuel shows that, while not equal to Pennsylvania and Ohio oils, owing to the low carbon and high sulphur, it is not inferior to the California petroleums in any marked degree. TABLE IX. ULTIMATE COMPOSITION. Beaumont. Penna.* Ohio.t Carbon 85.03 86.10 85 oo Hydrogen 12.30 13 . 90 13.80 Sulphur i-75 0.06 0.60 Oxygen and Hydrogen Loss on treatment with excess of 0.92 0.60 H 2 SO 4 . (Sulphuric acid) 39-o 21 .0 30.0 'Engler. t Mabery, Noble Co. TABLE X. BEAUMONT OIL. Specific gravity 25 C Flash Viscosity, P.R.R. pipette.. 0.912 Ord. Temp. 0.914 110 75" 0.8014 Ord. 42" 0.8293 Ord. 37" TABLE XI. VOLATILITY IN OPEN- DISH. Per Cent. Per Cent. Per Cent. Per Cent. no C., 230 F. : 7 hours. ... 162 C., 325 F. 7 " 19.19 31-31 20.0 27.0 41-2 43-0 47-3 58.0 205 C., 400 F. 7 " 57-57 49-0 59-0 68.0 To constant weight 105 C., 221 F. : 42 hours 48.0 48.0 48.7 58.7 162 C., 325 F.: 70 " 64.0* 57-0 61.0 71. 8f 205 C., 400 F.: 49 " 74-0 74.0 75-o 84.0 *49 hours. t42 hours. TABLE XII. DISTILLATION: ENGLER'S FLASKS. Beau- mont. Ohio. Penn- sylvania. Distillation begins Below 1 50 C >er cent. 110 C. 2-5 40.0 20. o 25.0 10. 30.0 S.o 7.0 85 C. 23.0 21.0 21.0 27.0 5-0 2-5 80 C. 21. 41.0 14.0 J23.0 (99.0 1.8 2.0 150 300 C 300 350 C 350 400 C Loss on acid treatment (150 300 C. fraction) 1 50 260 C per cent. Loss on acid treatment. Percentage of acid used " TABLE XIII. SPECIFIC GRAVITY AND REFRACTIVE INDEX. Beaumont. Ohio. Pennsylvania. Sp. Gr. Refrac. Index. Sp. Gr. Refrac. Index. Sp. Gr. Refrac. Index. Below 150.. 150 300.. 300 350.. 350 400.. (Amoi srm 0.8749 o . 9089 0.9182 int too ill.) i 473 1.501 1.508 0.7297 0.8014 0.8404 0.8643 1.412 1.442 1.468 1.481 0.7188 0.7984 0.8338 Paraffin I-4I5 1-437 1.462 1.470 After acid treatment. 150 300.. 0.8704 1-473 0.8006 1-443 0.7791 1.438 TABLE XIV. CALORIFIC POWER OF VARIOUS DESCRIPTIONS OP PETROLEUM, ETC. (B. REDWOOD.) Description of Oil. > 2cj t % "* Chemical Com- position. Coefficient of Expansion. 2<-3J ll- m & Effect in Heat Units. | a (J 6 P P & > Heavy Petroleum from West Virginia Light Petroleum from West Virginia Light Petroleum from Pennsylvania Heavy Petroleum from Pennsylvania American Petroleum . . Petroleum from Parma Petroleum from Pech- elbronn 0.873 0.8412 0.816 0.886 0.820 0.786 0.912 0.892 0.861 0.829 0.892 0-955 0.870 0.885 0.911 1.044 33-5 84-3 82.0 84-9 83-4 84.0 86.9 85-7 86.2 79-5 80.4 86.2 82.2 85.3 80.3 82.0 87-4 86.3 86.6 87.1 87.1 87.1 13-3 14.1 14.8 13-7 14.7 13-4 II. 8 12.0 13-3 13-6 12.7 II.4 I2.I 12.6 "5 7.6 12.5 13.6 12.3 11.7 12.0 10.4 3-2 1.6 3-2 1.04 1.9 1.8 i-3 2-3 0-5 6.9 6.9 2-4 5-7 2.1 (N. 0.) 8.2 (0. S'. N ) 104 O.I O.I I.I 1.2 0.9 2.5 0.00072 0.000839 0.00084 0.000721 0.000868 0.000706 0.000767 0.000793 0.000858 0.000843 0.000772 0.000641 0.000813 0.000775 0.000896 0.000743 0.000817 0.000724 0.000681 0.00091 0.000769 0.0008685 14.58 14-55 14.05 15-3 14.14 13.96 14.30 14.48 15-36 14.23 14.79 12.24 12.77 16.40 15-55 15.02 14-75 10, 180 10,223 9.963 10,672 9-771 10,121 9,708 I0.02O 10,458 IO,O85 10,231 9,046 8,916 11,700 11,460 10,800 IO,70O 10,831 10,081 Petroleum from Pech- elbronn Petroleum from Schwabweiler Petroleum from Schwabweiler . . . Petroleum from Han- over Petroleum from Han- over Petroleum from East Galicia Petroleum from West Galicia Shale Oil from Ardeche Coal Tar from Paris Gasworks . Petroleum from Balak- hany 6.822 0.844 0.938 0.928 0-923 0.985 Light Petroleum from Baku. Heavy Petroleum from Baku Petroleum residues from Baku Factories Petroleum from Java. . Heavy Oil from Ogaio &%& c? ^ o .3 "8. S ,? O 00 OO I- S _ _ J? .2 g 'I **s si ^ g : *1 >,S >> - -*> "^ G fl > "3 ^ r^ 3 >3 1** B : S ^ S >2. fc S 21 |S 238 OIL ENGINES. TABLE XVI. OIL FUEL. (B. REDWOOD.) Locality. Fuel. Sp. Gr. at 0.928 0.9 0.938 o.'886 Chemical Compo- sition. Heating Power. Car- bon. 87.1 84.94 86.6 84-9 84.9 86.894 85.491 80.583 83.012 Hy- ' gen. gen- II-7 .2 Actual Calori- metric (Ib. C. Units.) Calcu- lated (Ib. C. Heat Units.) Russian Caucasian " (Novorossisk) Pennsylvanian American Petrol, refuse Astatki Heavy Crude Refined Double " Crude " I3-96 -2 12.3 .1 11.63 -458 13-7 -4 13-107 14.2160.293 15.101 4.316 13.8893.099 10,340 I0,8oo 10,328 10,912 11,045 II.086 11,094 11,626 11,200 10,672 <> ii TABLE XVII. CALORIFIC POWER OF CRUDE PETROLEUM. (B. REDWOOD.) Sp. Gr. Calories. Heavy Lubricating Oil, White Oak, ) Western Virginia f Light Illuminating Oil, Oil Creek, Pa. 0.873 0.816 10,180 9.963 Oil from Dandang, *Leo Rembang, ) Java. \ 0.923 10,831 Light Oil from Baku 0.884 11,460 Oil from Western Galicia 0.885 10,231 " " Eastern " 0.870 10,005 " " Parma. . . 0.786 IO,12I " " Schwahweiler . 0.861 10,458 FUELS. 239 CALIFORNIA CRUDE OIL. The crude petroleum procured in the various oil fields of California, from the information available, ap- pears to vary considerably in its characteristics. Ac- cording to the report of the Chamber of Commerce of San Francisco, in 1902 the oil-producing fields of Kern River, Coalinga, Los Angeles, Fullerton, with many others, in which over 2,000 wells were in operation, produced an average daily supply of over 37,000 bar- rels. It has been used hitherto chiefly for fuel pur- poses, and having in most instances an asphaltum base, is most suitable for this purpose. The characteristics of the oil vary so widely, however, that while some samples can only be used for fuel, that produced in other wells would yield illuminating oils on distillation in considerable quantity. The following is the analysis of two samples of the distillates from the Kern River field: (Flash test was taken, using the open method. ) Gravity 0.901 0.859 Beaume 26.2 34 Flash 169 F. 119 F. According to Mr. Paul Prutzman,* the oil produced in Coalinga oil field varies from 11.5 Beaume to 45. The viscosity of various samples varies from 68 to 296, while the flash point varies from 220 to 278 F. This writer also refers to the refining qualities of various samples, from which it would appear that on distillation * Pacific Oil Reporter, Vol. 4, No. 35- 240 OIL ENGINES. while some of the oil would give far greater amount of kerosene (42 B.) than others, the average yield of kerosene on distillation would be about 14 per cent; while the engine distillate (48 to 52 B.) given off from the above-mentioned samples would also vary considerably in quantity, the average would, however, be approximately 14 per cent the products which were obtained being of a lighter quality than kerosene were inconsiderable. This fuel is now used on the Pacific coast in large quantities, both under boilers for gen- erating steam, in gas engines having first been gasified, as explained in Chapter XII., as well as in the oil engine proper, where it is vaporized by the same methods as with kerosene. FUEL OIL. The oil known as fuel or gas oil, as already stated, is procured in the process of fractional distillation after the lighter oils and the illuminating oils have been taken off. Various samples of this fuel have come within the writer's notice, the characteristics of which have varied considerably, as will be seen from the following table : FUEL OIL. Specific gravity . . 0.832 .878 Beaume 36 30.2 Flash-point 144 F. 298 F. Fire test 183 F. 247 F. This fuel is much used in oil engines in the United States. With the heavier grades a slight deposit of car- bon is left in the engines, which requires periodical re- moving. TEST OF FUELS 241 TABLE THE CALORIFIC POWER OP PETROLEUM OILS AND THE RELATION OF DENSITY TO CALORIFIC POWER. The following are extracts of tests of various samples of crude oils, representing the products from the principal oil fields of the United States, and were made by H. C. Sherman and A. H. Kropf, at Columbia University, N. Y., during 1908, and are re- printed from the Journal of the American Chemical Society.* DENSITIES AND HEATS OF COMBUSTION OBSERVED AND CALCULATED. Specific G'-avity, 15/15 . Baume Degrees. Calories per Gram. B. T. U. per Pound. B. T. U. calcu- lated. Per- centage Error. Description. O.7IOO 6 7 .2 ".733 21,120 20,938 0.91 Gasoline. 0.7830 48.8 11,121 20,Ol8 20,206 + 0.92 Kerosene. 0.7850 48.35 Il.Ilg 20,014 20,194 + 0.89 Cal. refined. 0-7945 46.2 11,128 20,030 20,098 + 0-33 W. Va. crude. 0.8048 44.0 11,149 20,068 20,010 0.29 Ohio crude. 0.8059 43-7 11,143 20,057 19-998 o 29 Penna. crude. 0.8o8o 43-2 11,001 19.802 19.979 + 0.88 Cal. refined. 0.8103 42.8 11,090 I9,9 6 3 19,962 o.oo Kansas refined. 0.8237 40.0 10,981 19,766 19,850 + 0.42 W. Va. crude. 0.8324 38.2 10,990 19.782 19-778 O.O2 Penna. crude. 0.8418 36.3 10,950 19,710 19,702 0.04 Ohio crude. o. 842 r 36.25 10,997 19-795 19,698 -0.48 Indian Ter. 0.8436 36.0 11,069 19,924 19,690 I.I? Indian Ter. 0.8510 34-5 10,958 19-724 19,630 0.47 Kansas crude. 0.8580 33-2 10,772 19,389 19.578 + 0-95 Kansas crude. 0.8597 0.8640 0.8914 0.8970 0.9065 32-8 32.05 27.1 26.1 24-45 10,766 10,867 10,690 10,753 10,751 19-379 19-555 19,242 19-355 19,352 19,562 19-530 I9-332 19,294 19,228 + 0-95 - 0.12 + 0.45 0.31 0.63 Illinois crude. California Ref. Texas crude. Texas crude. Texas crude. 0.9087 0.9158 24 t 22.9 10,712 10,318 19,282 18,572 19.213 I9,l66 0.35 Texas cruae. + 2.58 iCalif. crude. 0.9170 0.9644 22.7 15-2 10,613 10,327 19,103 18,589 i9- T 57 18,858 + 0.28 Fuel oil. + 1.42-lCalif. crude. * Journal American Chemical Society, Vol. XXX, No. 10, October, CHAPTER XIV. MISCELLANEOUS. OWING to the increasing use of the metric system, the following comparisons of United States and metric 'measures and weights, etc., prepared by C. H. Herter, are added. The unit of hngth is the metre = 39.37 inches; the unit of capacity is the litre = 61.0236 cubic inches; the unit of weight is the gramme = 15.43236 grains. The following prefixes are used for subdivisions and multiples : Milli y- Centi = y^-, Deci = T V Deca = 10, Hecto = 100, Kilo = 1000, and Myria 10,000. In abbreviations the subdivisions be- gin with a small letter, the multiples with a capital let- ter. For example : Millimetre (.001) denote d by mm. cm. dm. m. Dm. Hm. Km. ca. dm 2 . m 3 . dl. me. Kz. Centimetre (.01) Decimetre (.1) Metre (r.) Decametre (10.) Hectometre (100.) Kilometre (1000.) i Centiare (i m' 1 ). Square decimetre Cube metre. Decilitre. Milligram. Kilogram.. . MISCELLANEOUS. 243 fefc -g.lr* 0,0, CO-gO i- CO CO ^ M O*l-l > ' .Q X) C7 1 _ 1) m ' "is wfiS-s* 1 W 4^ * * |ll^ H^KS2||S < ^7 -S " 'S ^ x " g : ='2'o s " 3 = = gramme per Kg. per cm 2 E 5'oi^ S-fio-C^ uiKis; e s -3 s^ :^g ^5 SJ^_: rt ^ rt c< o3 O i o O U IS ES 3" ^ S- - - ||KE1| a u u s,5? = c: s r* .SdTTii l?L?l ^1 M tfl II o Q u 8,8, d H, r^ o q o o 244 OIL ENGINES. OB .g ^_: ^. 'P J^ 4D _ s~* "7 " ,n J j 4J i o o ^ S 'g J "d u 35 CO t/3 3 G Cu ^ 1 M ^ M | 1 "o G S, M > II II S w 3 Sj ^ a ll - cT c (A fc 1 1 00 METRIC to AND CAPACIT ^t CO in CO II i ^ ^ s o S = ^ |-g 3-^ % II g^O N g^> g 2 : ^| WEIGHT ) = 15.432 gn or 0.035274 a . = 2.20462 a 1 *c S i o ** t * CO tn co - g a? : S> : I" CO 3 g Q M O o O a r/D o II : 2 u . || || 6 || Z II II CA 3 u Q Z O II " C II OH 3 1 1 S 1 S 1 !.? -E 1 o 5 d u MH >> bc^ ^ - ^ T3 co O en4i-iM ot^wvO eno ^- 03 auiSug^ _ C ?* C . T C f q ^" S!l "" " MO OONtHl^- O^iH'C^M COO '?, o - : ^ b. b. nce nce ~i rti PM SD^EH a u ^ s-js-^f ll|S D'^'wW J 3 illlH iiM ^ u u 5 O EH ^ t^ c-4 n -f'en in c< n' d O O O CO ' ' ' ' n 1 ' O ' i-i pri 'saXSuBj, wmcien O inen-T NUP>I ^O 1- in O -tec inoco wOOOw ! 'oo BURGH. Jn to O vn to *" " N ^ o" ~t to r^-co en t d cj Oco o^^" t | ' r^ g s -fc suoSoV ,o !o^5 ,,1111 j^l MADE o.l % O > in m c<^ In t N ,.. | co en . c? ^-M cooOMOu^ Ow ' r^' ENGINES 03 3> M -1- o s co J^ o^ xn c<^ ,j 03 auiSug eno co in [ J j j | ^ | CO M 3" M J? S " " tS VARIOU 03 auiSug t w t^- t m Oco co' MM OO t % 6 M &, i ..WKU*, t^\^ enminin mc^y3 ^2 '.5 P!|l|!i||fi|pp|!i| OH Ui-Jco^i^PH Q^SWhSS QccHO* CHAPTER XV. MARINE DIESEL ENGINES. INTRODUCTORY. The Diesel oil engine has already been described in Chapter XII, both as regards its method of operation, its general construction and the remarkable economy effected by its use. In recent years the application of this engine for the propulsion of ships of small and large sizes, reaching several thousand horsepower, has received very careful atten- tion throughout the world. There are nearly 500 ships now operating propelled by Diesel engines, and numerous engineering firms well known for the superiority of their output in nearly all countries of Europe are engaged in building them, while in this country not so many firms have yet under- taken their manufacture. ADVANTAGES AND DISADVANTAGES. Some of the ad- vantages of this engine for marine purposes are: 1. The space occupied by it is less than that required for the steam engine and boilers with consequent greater space in the ship available for cargo. 2. The amount of attention required is less. The stokers and coal trimmers necessary with the steam engine ships being reduced in number if not entirely eliminated. 3. The facility for storing the fuel for the oil en- 253 254 OIL ENGINES. gine as compared with that of the coal necessary for a steam engine. 4. The greater distance that a ship equipped with the oil engine can travel as compared with the steam engine because less fuel is used by it. 5. The absence of funnels of the steam engine and the elimination of smoke. 6. The quick starting of the engine which can be accomplished at a moment's notice. 7. Elimination of standby losses that is, as soon as the engines are stopped the fuel consumption ceases. 8. Replenishing the store of fuel. At sea the coal- ing of a steamship is impracticable whereas oil fuel can, if necessary, be transferred at sea. The amount of coal, varying with its quality, con- sumed in a steamship for propelling purposes only, is somewhat over i-J Ibs. per I. H. P. per hour or 1.8 Ibs. of coal per B. H. P. per hour. These figures represent the best conditions and probably a fuel consumption of 2 Ibs. per B. H. P. per hour would be a fair estimate. The amount of liquid fuel used in a Diesel engine may be taken as 0.4 Ibs. per B. H. P. hour. Consequently, the weight of fuel consumed in the Diesel engine as compared with the steam engine is about one-quarter to one-fifth. Again, when the engine is running at a reduced speed the relative economy of the oil engine would then be greater than with the steam engine. The coal must be placed in a position accessible to the boilers ; liquid fuel can be placed so that the space occupied by it does not interfere with the storage of the cargo. This again increases the earning capacity MARINE DIESEL ENGINES. 255 of the vessel. It is estimated that on a cargo steam- ship equipped with reciprocating engines and boilers the weight is about 300 Ibs. per I. H. P., possibly 250 Ibs. for turbine propelled boats. The weight of a Diesel engine including all accessories would be ap- proximately 150 Ibs. per I. H. P. and high speed en- gines both of the steam or the Diesel type would each be respectively nearly one-half of the weights above given. The space occupied by the Diesel engine is about the same as that occupied by the steam engine alone thus the space occupied by the boilers is free in the Diesel engined ship and is available for cargo or other purposes. DISADVANTAGES. Some of the disadvantages of the Diesel engines for ships may be stated as follows : i Reliability the marine steam engine has been in operation for generations most engineers are thoroughly conversant with it. The Diesel engine is comparatively new and unknown by marine engineers. It must have special care and attention. With im- proper handling and even with some derangement the steamship can be temporarily repaired and brought into port, whereas the Diesel engined ship under the same conditions and with the same handling might be helpless. 2. The Diesel engined ship unquestionably requires a high grade of attention, more so than does the steam engined ship, which class of help may not be available and difficult to replace (in case of sickness or casualty) in foreign ports. 3. Owing to long experience of present marine en- 256 OIL ENGINES. gineers the steam engine can be adjusted and kept in proper operating condition more easily than can the Diesel engine. 4. Troubles with the steam plant can be more easily investigated and remedied than with an internal com- bustion engine, especially if it is in the hands of an inexperienced or careless or untrained attendant. 5. Maintenance of a plentiful supply of compressed air for starting and manceuvering. Many of these disadvantages will disappear or be- come unimportant as the Diesel engine becomes better known to marine engineers but they are worthy of consideration at the present time. TYPES. The Diesel marine engines have been built as follows: i Four cycle single acting. 2 Two cycle single acting. 3 Two cycle double acting, and 4 Junkers engine. For land purposes the four cycle engines have been built in the vertical type for slow and high speed and also in horizontal single acting and double acting type. The two cycle engine is also built for slow as well as high speed vertically and horizontally single acting. For marine purposes, of course, only the vertical types are built, and they are made non-reversible and directly reversible. The four cycle engine has hitherto been chiefly used for land purposes. Greater experi- ence has been gained with it for marine purposes also, and it has been thus used with satisfaction in smaller sizes. The tendency toward building the Diesel engine MARINE DIESEL ENGINES. 257 in larger sizes has brought about the desirability of the two cycle type. It has been found impracticable to build the four cycle cylinder of the large dimensions that would be required, and accordingly the only method of increasing the capacity of the engine was to multiply the number of cylinders. With the four cycle type this has proved complicated on account of the in- creased number of moving parts and more numerous valve motions, etc. For engines of over 1000 H. P. the two cycle type has found greater favor. Cylinders of over 1000 H. P. have been constructed and plans have been made for such of even larger sizes. The two cycle single- acting type, on account of its comparative simplicity and the absence of piston rods and stuffing boxes has hitherto been preferred to the two cycle double-acting type. The two cycle is capable of developing nearly double the power of the four cycle with cylinders of the same dimensions, at least, the power in the two cycle engine is increased about 75 per cent, over that of the four cycle. On the other hand, the four cycle type is slightly more economical than the two cycle, the fuel consumption being 0.4 Ibs. in the four cycle and .45 Ib. in the two cycle. In the four cycle type usually more complete combustion of the fuel is obtained and a somewhat lower grade of fuel can be utilized. For the larger size engines, that is those over 1000 H. P., the two cycle type has unquestionable merit over the four cycle in that it requires less space, its weight is less and it is simpler in construction. OIL ENGINES. MARINE DIESEL ENGINES. 259 Diagrams showing the opening and closing of air inlet, exhaust and fuel inlet valves of the four cycle type and the periods of exhaust opening and scaveng- ing and fuel inlet of the two cycle type are shown at Fig. 113- For the information of those who are not conversant with the different processes of operation of the two and four cycle type of engines diagramatic views are shown in Fig. 1 14 which were given by the late Dr. Diesel to illustrate the working of each of the above named type of engines.* Fig. 115 illustrates indicator cards showing pressures existing in the cylinder of each type which were shown at the same time. DETAILS OF CONSTRUCTION. The following is a brief description of some of the details of construc- tion of the Diesel engine as they vary with different makers. Some builders construct their engines with A frames supporting the cylinders and others build them with an enclosed crank chamber which is provided with re- movable covers so as to facilitate inspection of the bearings and moving parts inside the crank chamber. All leading builders now have standard types, the capacity of the engine being increased by increasing the number of cylinders. Two to eight cylinder engines being made. By thus standardizing, the cost of manu- facture is reduced likewise the number of spare parts *Address of Dr. Diesel to the Am. Soc. Mech. Engineers, Proceedings, Vol. 34, page 908. 260 OIL ENGINES. 1. Compression of pure air. 2. Inlet of pure air. 3. Combustion and expansion. 4. Exhausting of burnt gases. FIG. 114. MARINE DIESEL ENGINES. 26l which it is necessary to have on hand for repairs is reduced owing to their being interchangeable. The compressed air (about 800 Ibs. pressure) neces- sary for injection with the fuel is furnished by an auxiliary three stage compressor operated in some en- 1 Intake 2 Compression 3 Working Stroke 4 Exhaust 1 Scavenging 1 Compression 3 Working Stroke 4 Exhaust Four-stroke Cyr Two-stroke Cycle FIG. 115. gines from the end of the main crankshaft (see Fig. 122), in others it is furnished from compressor placed tandemwise in line with the motor cylinders, while in some engines this compressor is operated by levers from the connecting rod or crosshead. With the two cycle type the air necessary for scav- enging purposes (4 to 6 Ibs. pressure) is furnished by compressors or air pumps operated by levers from crosshead or piston rod (see Fig. 123), or the com- pressors are placed in line with the main cylinders (see Fig. 126), while in some makes a tandem cylinder and piston placed below the motor cylinder is used to fur- nish this air ; in that case the lower piston also acts as crosshead. In all cases an auxiliary engine is provided operat- ing a 2 or 3 stage compressor of sufficient capacity to 262 OIL ENGINES. charge the air tanks and maintain their pressure when the air is used for reversing the main engine and for manoeuvering purposes. VALVE MOTION. In the four cycle type and in the two cycle type where scavenging valves in the cylinder head are employed the valves are operated by means of a vertical shaft actuated by skew gearing from the crankshaft which vertical shaft is again geared to a horizontal shaft, running parallel with the crankshaft and in most engines supported by bearings on brackets attached to the upper part of the cylinders, while in others this shaft is placed lower down. To this shaft are keyed or otherwise attached the various cams re- quired to operate each valve. The motion of the cams is transmitted to the valves through reach rods and levers as shown in the various illustrations. COOLING. A sufficient supply of cooling water to maintain the proper temperature of the cylinder is necessary to circulate around its water jacket three to four gallons of water per B. H. P. hour which should not exceed an outlet temperature of 175 F. with the smaller diameter four cycle type. With the large diameter cylinders and of the two cycle type five to ten gallons of water per B. H. P. hour is required and the outlet temperature should not exceed 120 F. In the larger four cycle engines the exhaust valves are also water cooled, being made hollow, the cooling water entering and leaving through the hollow valve stem or guide. In some engines the piston is provided with a space for cooling water or cooling oil at the combustion end which liquid is conducted to and MARINE DIESEL ENGINES. 263 fro through sliding telescopic tubes. Provision for cooling the main crankshaft bearings is also made either by direct water cooling or by a system of cooling the lubricating oil referred to later. LUBRICATION. In Diesel engines of all types for marine work, particular attention has been paid to the arrangement of the lubrication. For the piston, special lubricating oil having a high flashpoint and with a very small percentage of animal oil is used. It is furnished by a positively operated force feed oil pump actuated from the camshaft or other moving part of the engine, preferably by a separate pump for each piston. The oil is delivered through four separate copper pipes to different parts of the piston and cylinder surface, thus ensuring proper distribution of the lubricant. The main or crankshaft bearings are furnished with a plentiful supply of oil which, in the later designs of engines is delivered by gravity and is forced around and on to the bearings. Then it is conducted through an oil filter and to a special tank in which is a cooling water coil, and after proper cooling descends to the sump to be pumped through the bearings again. The piston pin is lubricated either by a sliding tube placed on the piston or crosshead which is arranged to deliver the oil directly to the piston pin or in some de- signs lubricating oil is fed by pressure pump through the crankshaft which is then made hollow. The lubri- cant is forced on to the surface of the crankpin bear- ing and is conducted through a hollow space in the con- necting rod up to the piston pin. CYLINDER HEAD. All makers of the four cycle type 264 OIL ENGINES. have the cylinder head water-jacketted with the air and exhaust valves placed vertically in it as shown in Fig. 127, and the oil inlet sprayer placed in the cylinder head vertically as shown in the various sectional illus- trations. This design, however, is modified in the American Diesel engine built by the Busch Sulzer Bros. Diesel Engine Company of St. Louis as shown at Fig. 135, where the sprayer is placed hori- zontally and injects the fuel between the inlet and exhaust valves, which in this engine are placed in the' same line, the admission valve opening downwards being placed above, the exhaust valve opening upwards being placed below. The cylinder head of the two cycle type is shown in section at Figs. 126 and 127. It is water-jacketted similar to the four cycle type, in it being four scav- enger valves. These allow the entrance of air at a pressure 4 to 6 Ibs. (compressed in the compressor shown at Fig. 123) required to properly eject the ex- haust gases and completely fill the cylinder with air. The method of operating scavenging valves is shown at Fig. 126. The sprayer, sprayer valve, starting air valve and safety valve are also inserted vertically in the cylinder head and are shown in the sectional view. PISTONS. The piston is made of the ordinary trunk type (see Fig. 126), with 6 to 8 cast iron piston rings and piston or gudgeon pin. In many makes of engines it is made of sufficient length to act as a crosshead, the connecting rod being directly attached within it as shown in Fig. 126. Other builders, especially in engines of the larger MARINE DIESEL ENGINES. 265 size, have found it advantageous to use a crosshead with guides similar to that used in steam engine prac- tice. Then a shorter piston than that previously re- ferred to is used and is shown in Fig. 124. The differ- ent advantages of the crosshead are: 1. The guides within which it works are maintained at an even temperature and are not subject to expan- sion and contraction of the cylinder which affect the trunk piston. 2. Lubrication. It is simpler to lubricate the cross- head which does not come in contact wth the heated parts of the engine as does the trunk piston. 3. Adjustment. As the guides of the crosshead be- come worn they can be easily adjusted, whereas the trunk piston does not allow of adjustment for wear. 4. Piston Seizing. The possibility of the piston seizing through overheating or improper lubrication is minimized when the crosshead is used. The above remarks refer to the single-acting en- gines with the double-acting type, of course the cross- head is always necessary. There is a decided difference of opinion amongst engineers regarding the advantages of the crosshead, many maintaining that it is unnecessary and only in- creases the cost of manufacture of the engine, that it also increases the overall dimensions and that the trunk piston is a simpler design and that any wear in the cylinder is caused by the piston rings. SPRAYERS OR PULVERIZERS. One of the most im- portant parts of all oil engines is the sprayer or pulver- izer through which the fuel is injected into the cylinder 266 OIL ENGINES. I FIG. 116. FIG. 117. .- FIG. 118. MARINE DIESEL ENGINES. 267 or compression chamber. A great deal of attention has been devoted in recent years to this part. Sprayers for Diesel engines are shown at Figs. 116 to 120. Those of more recent design and used with Diesel engines are shown in Figs. 116 to 118. Fig. 116 shows FIG. 119. FIG. 1 20. the sprayer used by many makers and is suitable for lighter oils. Fig. 117 shows this sprayer as made in Sweden. Fig. 118 shows the sprayer adopted by Messrs. Deutz, Augsburg-Nurnberg and others where it is necessary to use a slight amount (about five 268 OIL ENGINES. per cent.) of low flashpoint fuel so as to make the ignition more rapid and allow combustion of the heavy crude oil or tar oil which is 95 per cent, of the charge to ignite more readily. The method of operation of this sprayer is first, admitting into the cylinder a small quantity of the lighter oil which is followed by the larger quantity of the heavy fuel, two oil injection pumps being used for this arrangement. In this sprayer, Fig. 118, the lighter oil enters through the passage c, the heavier oil of higher flashpoint through the passage b, and the lighter oil first enters and passes to the front of the valve. When the valve is raised to allow the heavier oil or tar and air (through a) to enter the combustion space, the lighter .oil is carried before it and enters first. Being of a lower flashpoint the ignition raises the temperature of compression suffi- ciently to ignite instantaneously the mixture including the heavier fuel. Fig. 120 shows a sprayer designed for attaching horizontally of the "open nozzle" type, where the fuel enters at a and is in direct communi- cation with the cylinder, but further distant than in that shown at Fig. 119. Another open type sprayer is shown at Fig. 119 as made by Messrs. Koerting. In this arrangement fuel enters the chamber a, which is in direct communication with the cylinder, either during the suction stroke or before the compression has ad- vanced. CHAPTER XVI. VARIOUS TYPES OF MARINE ENGINES. THE two cycle Diesel engine built by the firm of Carels Freres Ghent is shown at Fig. 122, and in sec- tion at Fig. 123 and Fig. 124. This engine, as shown in the illustrations has six cylinders 20.08 inch diam- eter and 36.22 inch stroke, at 130 R. P. M. it develops 1600 actual or brake horsepower. The cylinder is cast in one piece with the supporting A frame, a separate cylinder liner being inserted. The cylinder head cast in one piece is water jacketed, each equipped with four scavenging valves, fuel inlet valve, starting air inlet valve and safety valve. Compressed air for injection purposes is furnished by 3-stage air compressor of the Reavell type operated from the crankshaft direct (in some of the later engines the injection air com- pressor is operated by levers thus decreasing the over- all dimension lengthwise). The scavenging air pumps are operated by levers as shown in Fig. 123. Cylinder head, and cylinder are water cooled, the piston is also cooled by oil or water circulation. Indicator cards taken from this type engine are shown at Fig. 121. The starting or manoeuvering of the engines is ef- fected by means of compressed air furnished from air receivers, in which the pressure is maintained usually by an auxiliary engine and air compressor. 269 2 7 OIL ENGINES. Spring i" = 36i Ibs. (i mm. = Kg), M.E.P. = 76.i Ibs. (5.34 atm:). Injection air pressure 855 Ibs. (60 atm:). Rpm. 187. Spring i" = 36i Ibs. (i mm. = i kg). M.E.P. 92.5 Ibs. (6.5 atm:). Injection air pressure 995 Ibs. (70 atm:). Rpm. 187. FIG. 121. VARIOUS TYPES OF MARINE ENGINES. 2/2 OIL ENGINES. STARTING REVERSING. The two cycle marine Diesel engine here illustrated is controlled by means of the hand wheels shown at Fig. 125. A view of a part of the camshaft, manceuvering shaft, cams and valve motion is shown at Fig. 1253. FIG. 123. To start the engine it is necessary to raise the com- pressed air in the receivers to 600 or 800 Ibs. pres- sure which is done by means of auxiliary engine and compressor. The crankpin being set just past dead centre, compressed air enters the combustion space of VARIOUS TYPES OF MARINE ENGINES. 273 two (or three) of the cylinders, starting the pistons downward. In the remaining cylinders compression FIG. 124. takes place followed by ignition in the regular way. Subsequently fuel enters the cylinders previously re- 274 OIL ENGINES. ferred to, operated by compressed air, and they also come into operation in the regular way. In Fig. 125 are shown three hand wheels or levers. That shown at i controls the horizontal manceuvering shaft M (Fig. i25a) placed above the cylinders which is operated by means of a vertical shaft. The lever shown FIG. 125. at 3 controls the air motor indicated by 5. The hand wheel indicated by 2 is provided to effect the same re- sult and is used by hand in emergency. A dial showing what is occurring in each set of cylinders is at 4. In Fig. I25a is shown the camshaft A to which is attached the cam C actuating the scavenger valve lever B. The lever at D controls the fuel valve and E the air starting valve. These two valves being actuated through short VARIOUS TYPES OF MARINE ENGINES. 275 levers F and G and not directly from the cams. The maneuvering shaft H has a longitudinal movement and thus allows D and G, when reversing, to be brought in contact with the astern cams. Re- versing the direction of rotation of the crank- shaft is effected in about six ' seconds by turning handle i until indicator dial 4 points to "stop." This has turned shaft H through an angle allow- FIG. 1250. ing cam K to force out a small sliding part lifting the roller of the fuel valve lever. Lever 3 is now moved to operate reversing motor (this can also be effected by hand, using wheel) which revolves the cam- shaft through the necessary angle to properly operate the scavenge valves after reversal and also moves the manceuvering shaft H so as to allow levers F and G to be in contact with the astern cams controlling, start- 2/6 OIL ENGINES. ing and fuel inlet valves. Next handwheel i is moved till dial 4 shows all six cylinders starting up on air. This is effected by still further turning shaft H, thus cam L allows sliding piece to be in such position as to hold the starting valve lever out of contact with its cam. The next movement of handwheel i allows fuel to enter three cylinders by still further movement of shaft H which rotates cam K, its nose then no longer forces out the sliding piece which is brought back by spring and allows the fuel valve cam through the short lever to come into contact with its roller. The starting valve for its cylinder is similarly put out of operation. Further movement of handwheel i brings all six cylinders in regular operation with fuel. With the four cycle type a complete duplicate set of cams is provided. The process of reversing is similar in principle to that outlined above, that is, it is effected by means of the horizontal sliding movement of the camshaft and servo motors which having disengaged the cams and the valve lever rollers allows the sliding motion of the camshaft so as to bring into action the second set of cams so arranged as to open the air and exhaust valves at the proper period for reversal as well as the cam governing the oil inlet. Two or more cylinders being operated by compressed air, while the remaining ones have fuel inlet and commence regular operation. The auxiliary propelling engines in the cargo ship "France" are shown in longitudial section at Fig. 126, and in section through the cylinder at Fig. 127. They are of the Schneider-Carels-Diesel oil engine type of VARIOUS TYPES OF MARINE ENGINES. 277 2/8 OIL ENGINES. 900 actual H. P. four cylinder two cycle. Each cyl- inder is 17.716 inch diameter and 22.047 mcn stroke and operates at 234 R. P. M. Each engine is equipped with an air compressor for fuel injection, scavenging air pump as well as cooling water pumps and lubricat- ing oil pumps. As shown in the illustration the cylinder liners are inserted into the cylinder casings bolted to cast iron closed-in frames having large in- spection doors. Guards are provided inside the frame to prevent the lubricating oil from entering the cyl- inder. The cylinder head is similar to that previously described, being fitted with four scavenging valves, fuel inlet valve and safety valve. The cast iron pistons are made in two parts, the cooling water or oil for same circulating through the hollow connecting bolts. As will be seen from the illustration, besides the six piston rings at the top of the piston there are two at the lower part also, to prevent escape of gases into the crank case. The valve motion is similar to that previously described for this type of engine, the fuel and starting valve, however, in this engine being operated by the same lever. Reversing is effected by longitudinal move- ment of the cam shaft. The three-stage air compressor for fuel injection is driven directly from the crank shaft, which also furnishes the necessary air for charg- ing the air receivers for starting. The piston is lubri- cated by a pump driven from the indicator shaft delivering the oil at two opposite points of the piston surface. The cooling medium of the pistons is circu- lated by a pump through telescopic tubes. A salt water circulating pump delivers the cooling water first to the VARIOUS TYPES OF MARINE ENGINES. 279 FIG. 127. 28O OIL ENGINES. air cooler, then to the lubricating oil cooler and after- wards cools the circulating oil for cooling the piston ; it then circulates around the fuel injection air com- pressor and cylinder head. The exhaust gases pass through a water- jacketed pipe to the silencer, which is fitted with baffle plates, and from thence to the atmos- phere. Air receivers of approximately 115 cubic feet capacity are charged from an auxiliary engine and compressor. The total weight of the engine is approx- imately 1 60 Ibs. per actual H. P. The engine develops 1305 I. H. P. Fuel consumption 0.462 Ibs., lubricating oil consumption 0.012 Ibs., per B. H. P. hour. NEW LONDON SHIP AND ENGINE COMPANY. The four cycle marine Diesel engine as built by the New London Ship and Engine Company is shown at Fig. 128 and also in section at Fig. 129, which illustrates the specially designed valve motion consisting of two camshafts placed in bearings attached to either side of the enclosed crankcase. The camshaft on one side through a lever operates the exhaust valve, that on the other side the air inlet valve, the fuel inlet and fuel supply pump. This engine is built with four cyl- inders (120 B. H. P.) and six cylinders (180 B. H. P.) each being 9" diameter and 12^" stroke. Each engine operates at 350 R. P. M. The weight of the flywheel is about 2000 Ibs. The total weight of the engine 8000 Ibs. The engine being non-reversible, a special design of reverse gear is used. The compressed air at about looo Ibs. pressure necessary for injection with the fuel is furnished by a 2-stage compressor placed at the for- ward end of engine and actuated directly from the VARIOUS TYPES OF MAUtNE ENGINES. 28l 282 OIL ENGINES. crankshaft. The cylinders and cylinder head are cast in one piece, the air inlet valve and housing and the ex- haust valve being arranged horizontally and the fuel inlet or spray valve being vertical as shown at Fig. 129. The governor placed in the flywheel acts through levers on the suction valve of the fuel supply pump regulat- ing the amount of fuel as required by the load. The cooling water is supplied by centrifugal pump operated from the flywheel. Lubrication to all parts is effected by force feed pump. These makers also build two cycle type marine Diesel engines with enclosed crankcase in sizes from 30x3 to 2000 H. P. as well as the same type with open A-frame crosshead and crosshead guides from 500 to 2500 H. P., each of these types is single acting. The latter operates at a compartively slow speed. In both types the exhausting of the gases is effected by the usual method of exhaust ports in the cylinder walls and scavenging valves placed in the cylinder head through which the low pressure air enters, thus thoroughly ejecting the burnt gases. The fuel injection high pres- sure air is furnished by a two stage compressor oper- ated directly from the crankshaft, this compressor has greater capacity than is required for injection pur- poses, the excess air being stored and is employed for starting and reversing purposes. Force feed lubrica- tion is used throughout, the lubricant being cooled and contained in a closed circuit. Reversing and change of speed are controlled by one hand wheel. The two cycle enclosed crankcase engines operate at a speed of 480 R. P. M. with the 300 H. P. and 270 VARIOUS TYPES OF MARINE ENGINES. 283 FIG. 129. 284 OIL ENGINES. R. P. M. with the 2000 H. P. six cylinder construction. Total weight is about 50 Ibs. per B. H. P. The heavier type of 2 cycle engines with A frame construction operate at slower speed and weigh approximately 100 Ibs. per B. H. P. The two-cycle Diesel oil engine as made by Messrs. Sulzer, of Winterthur, Switzerland, is shown in section at Figs. 130 and 131.* It has been made of the four- and six-cylinder construction. As will be seen from the illustration, it is of the single-acting type, the ex- haust ports in the cylinder being uncovered by the piston at the end of its downward stroke, the scaveng- ing air entering through the two valves placed in the cylinder head. These makers are also constructing their engines with air inlet ports, thus eliminating the scavenging air inlet valves. This engine is equipped with a double-acting air scavenging pump operated from the crank shaft and also two-stage air compressor furnishing high-pressure compressed air for injection purposes. Forced feed lubrication is provided with all bearings. Fig. 132 shows in section a six-cylinder Diesel oil engine as made by the Maschinen Fabrik Augsburg Nurnburg (M. A. N.), also of the two-cycle type. As will be seen from the illustration, this engine has an upper and lower cylinder in which pistons operate. The upper cylinder is the motor cylinder, the lower cylinder being used for furnishing the *The illustrations Figs. 130 and 132 are reproduced by kind permission from the Am. Soc. of Mech. Engineers Journal, June, 1912, being embodied in an address therein by the late Dr. Rudolf Diesel. VARIOUS TYPES OF MARINE ENGINES. 285 286 OIL ENGINES. scavenging air the compressed air for injection pur- poses, being furnished by the two-stage air compressors placed in line with the other cylinders at the end of the engine. THE JUNKERS OIL ENGINE. Briefly described, this FIG. 131. engine operates on the two cycle plan, it consists of motor cylinder of greater length than other engines in which operate two pistons. The piston nearer the VARIOUS TYPES OF MARINE ENGINES. 287 288 OIL ENGINES. crankshaft is connected to its crank in the ordinary way, the piston farthest from the crankshaft moves in the opposite direction to that of the previously named piston, and is attached at its back end to side- rods supported on each side of the cylinder, which are actuated through connecting rods from cranks each side of the main crank. Thus a three throw crank is required, the two outside cranks being in line with each other, and are set at 180 from the main centre crank. In the motor cylinder walls are two sets of ports, one set for air inlet, the other for exhaust. The method of operation is as follows: As com- bustion commences the pistons travel in opposite direc- tions. Toward the end of the stroke the forward piston first uncovers the exhaust ports then the back piston uncovers the air inlet ports, allowing pure air at a slight pressure to enter the cylinder and scavenge it thoroughly, on the backward stroke the pistons ap- proach each other again performing compression, at the dead centre fuel is injected and expansion begins again. For marine service this engine is designed with two cylinders placed tandemwise and having four pistons in all. Many advantages are claimed for this design among which may be mentioned the simplicity of cyl- inder casting and the absence of strains through it, complete balance of the reciprocating parts improved lubrication of the pistons and cylinders, high aggre- gate piston speed, the absence of complicated cylinder heads, ideal combustion space and decreased loss of heat to the cylinder water jackets. CHAPTER XVII LARGE STATIONARY ENGINES IN recent years many engineering firms in the United States have taken up the manufacture of oil engines, nearly all of them being of the Diesel cycle of opera- tion. Some of these engines are being made of the vertical and others of the horizontal type, the former being largely made of the open crank case construc- tion ; that is, with the cylinders supported on A frames, thus allowing free access to all bearings and affording opportunity for inspection while the engine is in opera- tion. The latter are being made by different makers both of the single-acting and double-acting type operat- ing on the two-cycle principle and also on the four- cycle plan. THE SNOW CRUDE OIL ENGINE. The Snow Steam Pump Co. are now building two- and four-cycle hori- zontal single-acting oil engines operating on the Diesel cycle, and are shown in Figs. 133 and 134. The four- cycle engine shown at Fig. 133 has the air inlet exhaust and fuel inlet valves placed horizontally in the cylinder head, which are operated by cams placed on a hori- zontal cam shaft mounted at the rear of the cylinder head and actuated by gears from an intermediate shaft placed by the side of the cylinder. The fuel injection high pressure air is furnished by a two-stage air com- 289 290 OIL ENGINES. LARGE STATIONARY ENGINES. 29! pressor actuated directly from the crank shaft by crank disc. The Jahns type of governor controls the speed of the engine by operating through levers on the fuel supply pumps, lengthening or shortening the stroke of same by a wedge arrangement. The governor is mounted on the side of the main frame, and this allows easy removal of cylinder head when required. Lubri- cation of the piston is furnished by a Richardson posi- tive force feed pump, which also supplies lubricant for the valve stems and air compressors. This make of engine is equipped with cross-head operating in guides placed on the main frame of the engine, the piston being shorter than the ordinary trunk type of piston used where cross-head is not employed. Reference has previously been made to the advantages obtained by the use of the cross-head. The two-cycle type of engine is shown at Fig. 134. This engine operates on the two-cycle principle, as pre- viously described. Exhaust ports are placed in the cylinder wall and are uncovered by the movement of the piston at the end of its stroke. In the two-cycle type scavenging air inlet valves are placed in the cylin- der head with the fuel oil inlet valve ; the low-pressure air necessary for scavenging is furnished by the air compressor placed ahead of the two-stage air injec- tion compressor as furnished with the four-cycle type. The low-pressure scavenging air passes through a re- ceiver placed in the main frame of the engine. The valves are operated by the same method as that de- scribed with the four-cycle engine and the governor operates on the fuel supply pumps in a similar way. 2 9 2 OIL ENGINES. LARGE STATIONARY ENGINES. 293 The makers guarantee the successful operation of this engine on the lowest grade of fuel or crude oils, the fuel consumption being at full load 0.5 of a Ib. ; f load, 0.55 Ib. ; load, 0.6 Ib. Admission valv Cyi. head top plat FIG. 135. THE BUSCH SULZER BROS. DIESEL ENGINE. The four cycle Diesel engine manufactured by this com- pany in St. Louis, Mo., is shown in section at Fig. 135. 294 OIL ENGINES. LARGE STATIONARY ENGINES. 295 This illustration shows the arrangement of the differ- ent valves, sprayer, etc., as hitherto built by this firm.* The later type of vertical four cycle four cylinder 500 H. P. Diesel engine now being built by this com- pany is shown at Fig. 136. As will be seen from the illustration, the multi-stage air compressor for fur- nishing the injection air at about 1000 Ibs. pressure is now operated directly from the main crankshaft by crank disc at the forward end. The crankcase is of the enclosed type reinforced with vertical tie rods lubrication to all bearings is supplied by force feed pump. The oil inlet, air inlet, and exhaust valves placed in the cylinder head are operated by levers from the horizontal camshaft which revolves in enclosed oil case. The governor is mounted on the vertical shaft operated from the crankshaft which in turn is geared to the horizontal camshaft placed at the upper part of the cylinders. The later type De La Vergne "FH" horizontal single cylinder engine is shown in Fig. 137. This type of engine has been fully described and illustrated with sectional views in Chap. XII. In this later type the method of governing is im- proved a double overflow by-pass valve is employed which is regulated directly by the governor instead of the method previously described where the governor operates directly on the fuel supply pump. It will be seen from this illustration that the governor is now placed on the main frame instead of being supported from the cylinder head as on the previous engines. This *This type of engine is fully described in Chapter XII. LARGE STATIONARY ENGINES. 2Q7 design relieves the strain of the cylinder head and allows a greater access to it. These engines are now built in various sizes in the single, twin and four cyl- inder type from 65 to 800 H. P. INDEX TO APPENDIX Advantages of Diesel en- gine 253 Air pressure 272 Attention required 253 Busch Sulzer Bros, en- gine 293 Carel Freres type 269 Coal consumption, steam- ship 234 Cooling water 262, 278 Cross head 2^5 Cylinder head 263 De La Vergne type 295 Details of construction. .259 Diagrammatic views, 2- and 4-cycle 259 Diagrams valve move- ments 259 Disadvantages Diesel en- gine _'55 Exhaust gases 280 Exhaust ports 292 "France" ship engines 276 Fuel consumption, Diesel engine 254, 293 Fuel consumption, 2- and 4-cycle 257 "Junkers" engine ____ 256, 286 Lubrication 263 Manoeuvering ...... 269, 274 M. A. N. engine ......... 284 New London Ship and Engine Co ........... 280 Pistons ................. 264 Pulverizers ............. 265 Reversing .......... 272, 274 Scavenging ............. 261 Snow crude-oil engine... 290 Space occupied .......... 253 Speed of engines. .. .280, 282 Sprayers ................ 265 Starting ................ 272 Sulzer Bros, engine ...... 284 Two-cycle engines. .269, 282 Types Diesel marine ____ .256 Valve motion ............ 262 Weight of engine ....... 280 Weights, comparison of.. 255 299 INDEX ABEL oil-tester 90 Actual horse-power 63 Air compressing, horse- power required 125 Air-compressor at differ- ent altitudes 129 Air-compressors 123, 204 Air inlet choked 77 Air-inlet valve. .12, 39, 57, 61, 78, 145, 172, 175 Air-inlet valve, auto- matic 12, 77, 156 Air-pump 13 Air suction, noise of. ... 122 Air-suction pipe 78 Air-supply (Campbell) ... 151 Air-supply (Crossley) 149 Air-supply (Priestman) . . 152 Analyses, oil 232 Asbestos 58 Assembling oil engines... 53 Atmospheric line 70. 71 BALANCE weights 30 Balancing crank-shaft. ... 28 Balancing fly-wheel 30 Balancing formula 29 Barker Engine 197 Bates, F. H 221 Bearing caps 55 Bearings, crank-shaft.. 40, 158 Bearings, outside 172 Bearings, pressure on.... 40 Bearings, scraping in 54 Beau de Rochas Cycle, 15, 16, 76, 215 Beaumont crude oil 232 Belt centres 115 Belt, link 113, 115 Belt, loose 115 Belt, size of 116 B. H. P., to calculate.... 65 Brake, attaching 64 Brake, horse-power.. 23. 63, 64 Britannia Co.'s Engine... 192 CAMPBELL, governing, 13. 151, 175 Campbell oil engine de- scribed 172, 250 Campbell starting 150 Cams 37 Cams, setting 60 Circulating water-pipes. .. 97 Clerk, Dugald 87 Clutches, friction 137 Clutches, friction, advan- tages of 137 Clutches, friction, B and C type. 138 254 INDEX Coal oil I Combustion, bad 89, 153 Combustion, complete 90 Compression (Diesel) . ..5, 25 Compression in crank- chamber 180 Compression, increasing.. 79 Compression, irregular 19 Compression line 76, 78 Compression pressure, 22, 25, 164 Connecting-rod bearings 56 Connecting-rods 31, 32 Connecting-rods, diameter 33 Connecting-rods, phosphor bronze 31 Cooling towers 100 Cooling water 19, 201 Cooling water-tanks 96 Copper ring 58 Cost of installation 209 Crank-pin 42, 175 Crank-pin, dimensions.... 42 Crank-pin, size of 40 Crank-shaft 26 Crank-shaft, balancing... 28 Crank-shaft bearings. .42, 158 Crank-shaft, strength of.. 26 Crossley engine described. 168 Crossley engine, portable. 203 Crossley governing 171 Crossley measuring device. 168 Crossley starting 148 Crude oil vaporizer. .220, 231 Crude oil, Beaumont 232 Crude oil, California 239 Cundall engine described. 172 Cycles, different, discussed 18 Cyclic variation 35, 36 Cylinder clearance 25 Cylinder cover .-. . 25 Cylinder lubricating oil.. 140 Cylinder lubricators 58 Cylinder, two parts 57 Cylinders, different types 22, 24 DEFECTIVE air-supply 164 Defective oil-supply 164 Denton, Prof 218 De la Vergne engine 129, 185, 226 Diagram, analyzing 77 Diagram, good working.. 76 Diesel governing 217 Diesel heat balance 218 Diesel motor 5, 210 Diesel starting 210 Direct-connected engine and dynamo 117 Direction of rotation, re- versing 154 Distance pieces 55 Draining, water 104 Dynamo fly-wheel 115 Dynamometer or brake. . . 64 "ECONOMIST" Retort 221 Effective horse-power 63 Efficiencies, thermal, com- pared 87 Efficiency, increase of.... 83 Efficiency, mechanical. .23, 86 Efficiency, thermal 86 INDEX 255 Electric igniter. .. .5, 15, 152 Electric lighting plant, in- stallation of 113 Electric lighting, portable.2OO Engine (Campbell) 172 Engine (Cundall) 172 Engine frame 43 Engine (Hornsby-Akroyd) 140, 182, 211 Engine, ideal heat 21 Engine (Mietz & Weiss). 178 Engine, portable 200 Engine (Priestman) 175 Engines (Barker) 197 Engines (Britannia Co.'s) 192 Engines (Crossley) 168 Engines (Crossley porta- ble) 202 Engines (American Oil Engine Co.'s) 194 Engines driving dynamos..ni Engines, electric lighting.. 46 Engines (Fairbanks- Morse) 225 Engines (Traction) 205 Engines, knocking. . .159, 164 Engines, large size 206 Engines (Mietz & Weiss portable) 203 Engines, regulation of. .. .117 Engines, running, general remarks 153 Engines, running, light... 145 Erecting oil engines 53 Exhaust bends 41 Exhaust, choked 83 Exhaust gases... 90, 153, 165 Exhaust line 76, 83 Exhaust silencers 100 Exhaust temperature no Exhaust valve 13 Exhaust valve, opening of. 76 Exhaust washer 101 Expansion line 76, 81 Explosion 20 Explosion in silencer. .. .166 Explosive mixture. .. .10. 15 FAIRBANKS Morse Engine.225 Filter oil 49, 146, 160 Fire insurance 244 Flashing point of oil i Flashing point to test.... 90 Flickering of incandescent ' lights 119 Fluctuation in speed 37 Fly-wheels 35, 119 Fly-wheels, energy of 35 Fly-wheels for dynamo.. 115 Fly-wheels, formula for. . 37 Fly-wheels, keying on.... 57 Fly-wheels, peripheral speed 37 Foundations 113 Four-cycle 15 Frame, engine 43 Friction-clutches 137 Friction-clutches, advan- tages of 13? Friction-clutches, B and C type 138 Frost, provision for 99 Fuel-consumption test.... 87 Fuel injection. . . .10, 165, 216 256 INDEX Fuel, injection of 53 Fuel oil-tank 13, 49, 168, 172, 174, 176. 177, 180 Fuels 230, 236 GASES, exhaust 90 Gear, skew 43 Gear, spur 43, 160 Gear, starting 106 Governing (Campbell), 13, I5i, 175 Governing (centrifugal), 15, 168, 171, 172, 175 Governing (Crossley).. .171 Governing devices 44, 48 Governing (Diesel) 217 Governing (Mietz & Weiss) 179 Governing (Priestman), 15, i?6 Governor, hit-and-miss type 45 Governor hunting 148 Governor parts, renewing. 160 Governor, pendulum type. 45 Governor, Porter type. . . . 180 Governor, Rites 45, 189 Gravitation (fuel) .... 12, 175 Gravitation system 96 HEAT losses 22 Heat, utilization of waste.. 107 Heated air n Heat balance 87 Heat balance (Diesel) .. .218 Heating lamp 8, n, 12 Heating lamp instructions.i4i Horizontal and vertical types 50 Hornsby-Akroyd, instruc- tions for running, 140, 182, 211 Hornsby-Akroyd, method of vaporizing 9 Hornsby-Akroyd oil sup- ply 10, 180 Hornsby-Akroyd Traction Engine 205 Hornsby-Akroyd vertical type 187 Horse-power 63, 66 ICE and refrigerating ma- chines 133 Igniter, electric. .. .5, 15, 152 Igniter (Hornsby-Akroyd) 2 Igniters 2 Igniters (flame) 2 Igniters, heating 61 Ignition 140 Ignition (electric) 2, 7 Ignition (high compres- sion) 2, 215 Ignition (hot surface) 2, 7, 10 Ignition (hot tube), 2, 7, n, 148, 151 Ignition line 76 Ignition line, late 80 Ignition line, too early. . 79 Ignition, regulating 80 Ignition, retarding 81 Impulse on piston 17 Incandescent lights 116 257 Incandescent lights, flick- ering of 119 Indicated horse-power.. 23, 66 Indicator attaching to en- gine 71 Indicator cock 66 Indicator, Crosby 67 Indicator diagram, 75, 170, 174, 184, 218 Indicator diagram, light spring 88 Indicator, diagram meas- uring 73 Indicator in place 64 Indicator, left or right hand 70 Indicator reducing motion 71 Indicator springs 69 Ingredients for founda- tions 113 Installation, Cost of 209 Instructions for running Hornsby-Akroyd 140 Instructions for running oil engines 139 Insurance, Fire 244 JOHNSTON oil Engine 191 Junk rings 55 KNOCKING in engine. .159, 164 LARGE size Engines 206 Leakage in crank-chamber 19 Leakage of piston-rings, 61, 78, 165 Leakage of valves 78 Leakage of water into cyl- inder 63, 166 Lights, incandescent n6 Line, atmospheric 70, 71 Line, compression 76, 78 Line, exhaust 76, 83 Line, expansion 76, 81 Link belt 113, 115 Loose belt 115 Loss of power 165 Lubricating cylinder oil.. 140 Lubricators, cylinder 58 Lucke & Verplank Va- porizer 8 MAGNETO 4 Measuring device (Cross- ley) 168 Mechanical efficiency, 23, Si, 86 M. E. P 67, 81 M. E. P. regulated 47 Method of vaporizing (Crossley) n Method of vaporizing (Campbell) 12 Method of vaporizing (Hornsby-Akroyd) .. 9 Method of vaporizing (Priestman) 13 Method of governing (Campbell) 175 Method of governing (Diesel) 217 Method of governing (Mietz & Weiss) 178 258 INDEX Method of governing (Priestman) 176 Metric measures 241 Mietz & Weiss engine described, 52, 128, 178, 211, 203 Mietz & Weiss engine governing 179 Mixture oil, vapor and air 14 Moore, C. C. & Co. . .206, 222 Motor, Diesel 6, 210 Multi-cyclinder engines... 51 NORRIS, William 26 OIL, Beaumont 232 Oil, California 239 Oil, crude 231 Oil cylinder, lubricating... 140 Oil engines, driving dy- ' namos in Oil engines, instructions for running 139 Oil filter 49, 146, 160 Oil injection 10, 216 Oil inlet 12 Oil measurer (Crossley).. n Oil-pump 9, 143, 172 Oil-pump, testing 147 Oil supply (Campbell)... 151 Oil supply (Crossley) ... .171 Oil supply (Diesel) 215 Oil supply (Hornsby-Ak- royd) 182 Oil supply, limiting. . .89, 164 Oil supply (Mietz & Weiss) 177 Oil-supply pipes.. 57, 61, 146 Oil supply (Priestman).. 15 Oil-supply pump 178 Oil sprayers 13 Oil, viscosity of 93 Otto cycle 15, 76 Otto patent 19 PARAFFIN ( Scotch) i Petroleum i Petroleum (crude) 2, 220, 231 Petroleum. See Tables. Pipe, air-suction 78 Piston 33, 35. 41, 153 Piston, blowing, 165 Piston, fitting 55 Piston lubrication.5o, 158, 170 Piston-rings, 34, 55, 56, 154, 158, 159 Piston speed 22, 34 Piston, taking out 158 Piston, water-jacketed 34 Planimeters 72 Planimeters, directions for using 74 Plants, pumping 131 Portable engines 200 Portable engines, con- struction of 200 Port openings 39 Pressure of explosion.... 20 Pressure on bearings.... 40 Priestman engine 14, 175 Priestman, governing. 15, 176 Priestman, starting 152 Priming cup (Crossley) ..148 INDEX 259 Processes in cylinder of engine ' 59 Products of combustion.. 18 Pump, oil-supply 49 Pump, water-circulating... 98 Pumping-plants 130, 131 Pumps, efficiency of 133 Pumps, horse-power re- quired 132 RADIATORS for cooling 99 Ratio, air and oil vapour.. 7 Refrigerating machines. . .133 Refrigerating machines, horse-power required..i36 Refrigerating machines, rating of 133 Regulation of engines. .. .117 Retort, "Economist" 221 Reversing direction of ro- tation 154 Rhumkorff coil 5 Rings, junk 55 Rings, piston, 34, 55, 56, 154, 158, 159 Rites governor 45, 189 Robinson, Wm.. .178, 220, 250 Running oil engines 139 SELF-STARTER 105 Self-starter (Hornsby- Akroyd) 105 Silencers, exhaust 100 Simplicity of construction 22 Single cycle 16 Skew-gear 43 Specific gravity...:, 232, 235 Speed counter (Hill) 85 Speed, regulation of 154 Sprayer 13, 14 Spray holes 147 Spur gear 43, 160 Starting 7, n, 215 Starting (Campbell type) 150 Starting (Crossley type). .148 Starting (Diesel motor).. 215 Starting, difficulties of 61, 143, 164 Starting gear 106 Starting (Hornsby-Ak- royd) 142 Starting (Priestman type). 152 Starting valve 215 Straight line principle 175 Stroke, ratio 26 Suction line 76 TACHOMETERS 83 Tachometers, portable. ... 84 Tank 49 Tank, fuel consumption.. 64 Tank, water 141 Temperature of cooling water 81, 100 Temperature, exhaust no Test (Diesel) 220 Test (Hornsby-Akroyd) 247, 250 Test (Priestman) 178 Test (Various) 247-251 Testing compression. .61, 164 Testing flash-point. . .90, 232 Testing fuel consumption 87 Testing new engine 59 260 Testing, object of 59 Testing oil-pump 147 Testing sprayer 61 Testing water-jackets 63 Thermal efficiency 86, 218 Timing of ignition 162 Traction Engine 205 Tube igniter 3, 5, 163 Two-cycle system. .15, .44, 177 VALVE, air and exhaust, 39, 57, MS, 158, 216 Valve, back pressure 146 Valve by-pass 45. 180 Valve closing-springs 39 Valve exhaust opening... 60 Valve, lift of 78 Valve mechanisms 43 Valve, overflow, oil 146 Valve starting 215 Valves 41 Valves and valve-boxes.. 38 Vapor inlet-valve.. 1 1, 12, 150 Vaporizer 7 Vaporizer, advantages of. . S Vaporizer (Campbell) 5 Vaporizer (Crossley)..n, 150 Vaporizer, difficulties of . . 9 Vaporizer heated by ex- haust 14 Vaporizer, heating 61, 152 Vaporizer (Hornsby-Ak- royd) 9 Vaporizer (Priestman).. . 13 Vaporizer, to heat 141 Vaporizer valve-box 145 Vaporizer, water-jacketed. 141 Vaporizers, crude-oil 220 Vertical engines 51 Vibrator 6 Viscosity of oil 93 WASHER, exhaust 101 Waste heat, utilization of.. 107 Water-circulating pipes... 97 Water-circulating pump. . 98 Water cooling 201 Water draining 104 Water in exhaust pipe 104 Water-jackets 57, 212 Water leakage 166 Water injection 52 Water space 25 Water-tanks, capacity of.. 96 Water-tanks, cooling. .96, 141 Worm-gear 43, 160 DE LA VERGNE OIL ENGINES FOR ALL PURPOSES TYPE " HA " HORIZONTAL 10 TO 250 H.F. TYPE " FH " HORIZONTAL 85 TO 250 H.P. TYPE " S " VERTICAL 4 TO 25 H.P. Will operate on crude, fuel or kerosene oil WE GUARANTEE THAT THESE ENGINES WILL PRODUCE ONE BRAKE HORSE POWER HOUR ON LESS THAN ONE POUND OF OIL These engines will reduce your power expenses from 50 to 75 per cent. // interested write for Catalogue G. DE LA VERGNE MACHINE CO. Foot of East 138th Street, New York ISOLATED PLANT A magazine devoted to spreading and making public FACTS regarding the Installation and Operation of Private Power Plants. Also gives information in regard to Preventable Wastes in Isolated Plants and Mistakes in Plant Designs. PUBLISHED BY The Isolated Plant Publishing Co. 43-45 West 34th Street, New York City Price, 10 cents a copy 50 cents a year j : i ' : . Send for sample copy P. R. Moses, E.E., Editor. Rossiter Holbrook, Gen. Mngr. GOULDS Efficient Triplex Power Pumps When in the market for pumping equipment look up Goulds Pumps for every service They are absolutely the most efficient pumps on the mar- ket today. Send us your conditions and we will guar- antee you an efficiency which will surprise you. Goulds Pumps are not cheap pumps, but they are the best pumps made. New York Boston Philadelphia Chicago Pittsburg Los Angeles THE GAS ENGINE An 84 page monthly devoted to gas, gasoline and oil engines station- ary, marine, automobile, aeronautic. Practical ^ Semi-Technical Plants illustrated Designs shown Operation explained " Answers to Inquiries" column Specimen Free $1.00 per Year Canada $1.25 Foreign $1.50 Gas Engine Calculator a neat card- board device to tell H.P. of engines without calculation. 50c. postpaid. Send for our catalogue " D " of Gas Engine Books. We publish and carry in stock the largest line of books of this character. The Gas Engine Publishing Co, 202 E. 7th St. Cincinnati, O. MIETZ & WEISS OIL ENGINES For All Purposes Are the Cheapest Power on Earth. In Sizes from 1 to 200 H.P. MARINE AND STATIONARY 85,000 H.P. in Operation. Used by the U. S. and Foreign Governments. OPERATE ON KEROSENE, FUEL OR CRUDE OILS AND ALCOHOL. Durable, Simple, Reliable, Safe and Economical. AUGUST MIETZ 123-138 MOTT ST. 87-89 ELIZABETH ST. NEW YORK A Noiseless Air Compressor Jt Triumph In Pneumatic Engineering UNEQUALLED for Big Hotels Office Buildings Sanitariums Hospitals, etc. and where quietness is imperative UNRIVALLED for ALL Manufacturing Granite Sheds Quarries Foundries Well Pumping New Fields, etc. and all purposes where requirements are Most Exacting Air Compressors--A.ll Sizes--All Types We Solicit Your Inquiries Bury Compressor Co., Erie, Pa. OUR MONTHLY LIST OF TECHNICAL BOOKS WILL Keep You Posted on the New Books SEND US YOUR NAME AND ADDRESS We do not make any charge for this valuable information SPON & CHAMBERLAIN Importers and Publishers of Technical Books 123-125 LIBERTY ST., NEW YORK, U.S.A. THE LIBRARY UNIVERSITY OF CALIFORNIA Santa Barbara THIS BOOK IS DUE ON THE LAST DATE STAMPED BELOW. IOOM 11/86 Series 9482 Of CAUFORNIA o VW9W9 ViNYS