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Viewing 43681 to 43710 of 43870
1921-01-01
Technical Paper
210023
J G VINCENT
Stating that economy and performance are diametrically opposed in that the greater the performance demanded the less the economy is likely to be, the author mentions that the gasoline bill of the average user is not the major portion of his expense and asserts that economy is determined very largely by the engine design, the chassis design and the tires. The subject of engine design is outlined and consideration is given to acceleration during periods of coasting. Discussing briefly the chassis and the tires, attention is given to oil and tire economy, followed by statements regarding design from the viewpoint of service and performance as influenced by gear-ratios and gearshifting.
1921-01-01
Technical Paper
210018
S E SLOCUM
1920-01-01
Technical Paper
200079
E R GREER
Rear-drive trucks and tractors are popularly accepted as being all that is desired so long as working conditions are not bad enough to prevent their operation. Caterpillars are admitted to be able to go where it is so soft that no other vehicle can navigate, but they are considered as too slow, awkward and expensive to use where the work can be done with wheel-equipped machines. The paper discusses the field of the four-wheel drive. The experience of the Army in motor-transport work is referred to and the application of four-wheel drive to tractors is discussed in some detail.
1920-01-01
Technical Paper
200076
OTIS E GRINER, MARK A SMITH
The feeling that a truly heavy-duty engine for truck and tractor service was not available led the company represented by the authors to commence the development of an engine that would be capable of high speed as well as have ability to develop maximum horsepower and torque at low or medium speeds. Five specific requirements are stated for a tractor and three for a truck engine; the requirements of a universal truck and tractor engine are then specified under six headings. The special features of design of the engine developed are described in minute detail and illustrated by photographs and charts, seven definite features being mentioned as having been productive of the desired results. The testing apparatus is described and power and torque curves, a timing diagram and capacity curves of the water and oil-pumps are presented. Gasoline was used as fuel, although the engine is designed to use either gasoline or kerosene and is said to be adapted to the use of the heavier fuels.
1920-01-01
Technical Paper
200075
L G NILSON
The free, resilient, self-expanding, one-piece piston-ring is a product of strictly modern times. It belongs to the internal-combustion engine principally, although it is applicable to steam engines, air-compressors and pumps. Its present high state of perfection has been made possible only by the first-class material now available and the use of machine tools of precision. The author outlines the history of the gradual evolution of the modern piston-ring from the former piston-packing, giving illustrations, shows and comments upon the early types of steam pistons and then discusses piston-ring design. Piston-ring friction, the difficulties of producing rings that fit the cylinder perfectly and the shape of rings necessary to obtain approximately uniform radial pressure against the cylinder wall are considered at some length and illustrated by diagrams.
1920-01-01
Technical Paper
200077
Thomas Midgley, Jr.
ABSTRACT
1920-01-01
Technical Paper
200002
O C BERRY
The paper is based upon the results of tests made by the Purdue Engineering Experiment Station to study the effect upon engine performance of varying the proportions of fuel to air in the mixture, and its object is to determine the variation in the mixture requirements of an engine at different rates of flow of air through the carbureter. The method of conducting the tests is described. The results are plotted in the charts shown and are discussed in some detail, special discussion regarding the effect of speed and load being presented, and the facts brought out by the tests are summarized. In the general discussion that follows, four definite conclusions regarding the richness of the fuel mixture in its relation to the maximum power are stated, and a like number of definite conclusions concerning the richness of the mixture in relation to maximum efficiency are also given.
1920-01-01
Technical Paper
200006
E G GUNN
The two broad divisions of aluminum pistons from a thermal standpoint are those designed to conduct the heat from the head into the skirt and thence into the cylinder walls, and those designed to partly insulate the skirt from the heat of the piston head. Pistons of the first type seem logical for heavy-duty engines; those of the second type are better suited for passenger-car engines. The objections of wear, piston slap, excessive oil consumption and crankcase dilution are stated as being the same for aluminum as for cast-iron pistons; and these statements are amplified. Piston slap is next considered and, as this can be overcome by using proper clearance, pistons of the second design tend to make this condition easier to meet. Many tests show that when too much oil is thrown into the cylinder bores, tight-fitting pistons and special rings will not completely overcome excessive oil consumption.
1920-01-01
Technical Paper
200005
H C GIBSON
First reviewing the history of the progressive insufficiency of the supply of highly volatile internal-combustion engine fuels and the early efforts made to overcome this by applying heat to produce rapid vaporization, the author gives an outline of the methods already found valuable in offsetting the rising boiling points of engine fuels and states the resulting three-fold problem now confronting the automotive industry. The tendency to subordinate efficient vaporization to the attainment of maximum volumetric efficiency is criticised at some length and the volatility of fuel is discussed in detail, with reference to characteristic distillation, time of evaporation and distillation-temperature curves which are analyzed. Heating devices are then divided into four classes and described, consideration then being given to fuel losses outside the engine.
1920-01-01
Technical Paper
200015
STANWOOD W SPARROW
The author proposes to determine what features of spark-plug construction cause preignition and how this preignition manifests itself. To this end observed conditions on an Hispano-Suiza aviation engine following 4 hr. of an intended 6-hr. run are reported, with supplementary tests and observations. This resulted in experiments made to determine the cause of preignition, using spark-plugs constructed so that different features of their design were exaggerated. Illustrations of these plugs are shown and the results obtained from their tests are described. The different observed peculiarities are then stated, analyzed and compared with normal spark-plug performance. The experiments serve as a means of identification of special forms of preignition and as an indication of the abnormally high temperatures to which valves and combustion-chamber walls are thus subjected.
1920-01-01
Technical Paper
200019
WILLIAM C DAVIDS
The comments the author makes regarding fuels, lubricants and engine and piston performance are suggested by pertinent points appearing in papers presented at the 1920 Annual Meeting of the Society. A list of these papers is given. The subjects upon which comments are made include salability of a car, engine balancing, pressure and chemical constitution of gasoline at the instant of ignition, the use of aluminum pistons, the success attending the various departures from orthodox construction, gasoline deposition in the crankcase and cleanness of design, as stated by Mr. Pomeroy; the performance of a finely atomized mixture of liquid gasoline and air and the contamination of lubricating oil by the fuel which passes the pistons, as discussed by Mr. Vincent; the dilution of lubricating oil in engine crankcases and the saving that can be effected by its prevention, as mentioned by Mr. Kramer; and tight-fitting pistons and special rings as presented by Mr. Gunn.
1920-01-01
Technical Paper
200020
HOLBROOK C GIBSON
Shortly after the armistice, the author witnessed the surrender of the German submarine fleet and subsequently inspected 40 of the 170 submarines first surrendered. He also inspected 185 submarines in Germany. Practically all the engines were of the Machinenfabrik Ausburg-Nürnburg four-cycle Diesel type, of 300, 550, 1200 and 1750 hp. There were but five Krupp two-cycle engines. Brief comment is made regarding the design of these engines. The author, who supervised the dismantling of the German submarine U-117 at the Philadelphia Navy Yard, gives a detailed description of its engines, which were of the 1200-hp. type. This includes comments regarding materials, design details, valve mechanism, starting and reversing gear, lubrication, cooling and accuracy of workmanship. The air-compression system and some of its auxiliaries are outlined.
1920-01-01
Technical Paper
200021
JOSEPH VAN BLERCK
The automobile engine, as used in passenger cars and a large percentage of trucks, is not adapted to use in motor boats. It is not built substantially enough for this, inasmuch as the power output of the motor-boat engine, except during starting or landing, is always 100 per cent. In view of this and because tractor, truck and marine engines are of the same family, it appears that if a truck or tractor engine were made with 100 per cent continuous power output capacity it would be satisfactory for marine use. The author describes and illustrates a tractor engine modified for marine use. The lubrication system of this engine is explained. The respective merits of right and left-hand engines are discussed. It is stated in a twin-screw boat that it is unnecessary to have both engines run out-board; that both can turn in the same direction without causing material difference in results.
1920-01-01
Technical Paper
200007
G E A HALLETT
If at great altitudes air is supplied to the carbureter of an engine at sea-level pressure, the power developed becomes approximately the same as when the engine is running at sea level. The low atmospheric pressure and density at great altitudes offer greatly reduced resistance to high airplane speeds; hence the same power that will drive a plane at a given speed at sea level will drive it much faster at great altitudes and with approximately the same consumption of fuel per horsepower-hour. Supercharging means forcing in a charge of greater volume than that normally drawn into the cylinders by the suction of the pistons. Superchargers usually take the form of a mechanical blower or pump and the various forms of supercharger are mentioned and commented upon. Questions regarding the best location for the carbureter in supercharged engines are then considered.
1920-01-01
Technical Paper
200010
DONALD MACKENZIE, R K HONAMAN
Flame propagation has received much attention, but few results directly applicable to operating conditions have been obtained. The paper describes a method devised for measuring the rate of flame propagation in gaseous mixtures and some experiments made to coordinate the phenomena with the important factors entering into engine operation; it depends upon the fact that bodies at a high temperature ionize the space about them, the bodies being either inert substances or burning gases. Experiments were made which showed that across a spark-gap in an atmosphere of compressed gas, as in an engine cylinder, a potential difference can be maintained which is just below the breakdown potential in the compressed gas before ignition but which is sufficient to arc the gap after ignition has taken place and the flame has supplied ionization. These experiments and the recording of the results photographically are described.
1920-01-01
Technical Paper
200014
LEWIS L SCOTT
It is stated that the general performance of the steam-propelled automobile has never been equalled by that of the most highly-developed multiple-cylinder gasoline cars and that it is significant that no innovation in the gasoline car has yet been able to give steam-car performance. This led to an effort to remove the troublesome features of the steam car, rather than to complicate the gasoline car further by attempting to make it duplicate steam-car performance. The paper describes in detail the steam automotive system developed by the author and E. C. Newcomb, including the boiler, the combustion system and its control, the engine and the condensing system.
1920-01-01
Technical Paper
200026
SAMUEL R PARSONS
The paper defines properties that describe the performance of a radiator; states the effects on these properties of external conditions such as flying speed, atmospheric conditions and position of the radiator on the airplane; enumerates the effects of various features of design of the radiator core; and compares methods that have been proposed for controlling the cooling capacity at altitudes. Empirical equations and constants are given, wherever warranted by the information available.
1920-01-01
Technical Paper
200025
GROVER C LOENING
The annual report covering transportation by the largest British air-transport company laid particular emphasis upon the greater value of the faster machines in its service. Granted that efficient loads can be carried, the expense, trouble and danger of the airplane are justified only when a load is carried at far greater speed than by any other means. A reasonable conclusion seems to be that we can judge the progress made in aviation largely by the increased speed attainable. It is interesting and possibly very valuable therefore to inquire into the relations of power and resistance as applied to small racing machines with aircraft engines that are available.
1920-01-01
Technical Paper
200071
GEORGE E A HALLETT
Ignition is discussed in a broad and non-technical way. The definition of the word ignition should be broad enough to include the complete functioning of the ignition apparatus, beginning from the point where mechanical energy is absorbed to generate current and ending with the completion of the working stroke of the engine. The ignition system includes the mechanical drive to the magneto or generator and the task imposed on the system is by no means completed when a spark has passed over the gap of the spark-plug. Ignition means the complete burning of the charge of gas in the cylinder at top dead-center, at the time the working stroke of the piston commences. The means employed to accomplish this result is the ignition system. In the present-day type of gasoline engine a spark produced by high-voltage electricity is almost universally used for ignition. This high-voltage electricity is produced by a transformer.
1920-01-01
Technical Paper
200063
J H HUNT
A brief outline of the elementary principles of the operation of jump-spark ignition systems is given preliminarily to the discussion of the advantages of battery-type systems, and four vital elements in a jump-spark ignition system are stated. A diagram is shown and explained of an hydraulic analogy, followed by a discussion of oscillating voltage and oscillograms of what occurs in the primary circuit of an ignition system when the secondary is disconnected. The subjects of spark-plug gaps and current values receive considerable attention and similar treatment is accorded magneto speeds and spark polarity, numerous oscillograms accompanying the text. The effects of magneto and of battery ignition on engine power are stated and commented upon and this is followed by a lengthy comparison of battery and magneto ignition, illustrated with charts.
1920-01-01
Technical Paper
200069
C F KETTERING
The automotive industry was considered a mechanical one until fuel difficulties caused a realization that the internal-combustion engine is only a piece of apparatus for the effective utilization of chemistry. The only great cloud on the horizon of the automotive industry today is the fuel problem, one way to dispel it being to increase the supply and the other to make the automotive device do what it has been designed to do. The author reviews the production of oil and of automotive apparatus, considers the available fuels and states the two distinct parts of the fuel problem as being first carburetion and distribution, external to the engine and one of purely physical relationship, and, second, the combustion of fuel inside the engine cylinder. The subjects of regulating combustion by additions to the fuel, the chemistry of fuels and the burning of heavy fuels are discussed at length.
1920-01-01
Technical Paper
200070
J F FOX
ABSRACT It has long been recognized that, in automotive engines, particularly those of six or more cylinders, excessive vibration is apt to occur despite all precautions taken in balancing; and that this is because the engine impulses coincide at certain speeds with the torsional period of the crankshaft, or rate at which it naturally twists and untwists about some point or points as nodes. Very serious vibration occurred in the main engines for the United States submarines S 4 to S 9, which are required to complete five specified non-stop shop tests and an investigation was made of which the author reports the findings in detail, illustrated with photographs and charts.
1920-01-01
Technical Paper
200056
W E LAY
Two series of tests were made in 1918; one to determine whether the mixture giving best economy and that giving maximum power is a constant quality for all conditions of speed and power output; the other to ascertain what effect changes in the temperature of the fuel-intake system have on the quality of the mixture which gives the maximum power and that which gives best economy. The standard United States ambulance four-cylinder engine was used for these tests, its carbureter having a primary air passage, a primary fuel-jet, an auxiliary air passage with an air-valve and a secondary fuel-jet, the manifold being cast integrally with the cylinder block and a curved riser conducting the fuel mixture from the carbureter to it. The testing methods and fuel consumption measurements are described.
1920-01-01
Technical Paper
200060
P S TICE
From a laboratory examination of the controlling relationships between carburetion and engine performance still in progress, the general conclusions so far reached include fuel metering characteristics, the physical structure of the charge, fuel combustion factors and details of engine design and manufacture. In every throttle-controlled engine, the variation in fuel metering for best utilization is inversely functional with the relative loading and with the compression ratio, but the nature of the fuel leaves these general relationships undisturbed. The physical structure of the charge influences largely the net engine performance and the order of variation of the best metering with change in load. Perfect homogeneity in the charge is theoretically desirable but entails losses in performance.
1920-01-01
Technical Paper
200049
H M CRANE
Emphasizing the necessity of persuading fuel manufacturers to improve the suitability of internal-combustion engine fuel by the mixture of other materials with petroleum distillates, and realizing that efficiency is also dependent upon improved engine design, the author then states that results easily obtainable in the simplest forms of automotive engine when using fuel volatile at fairly low temperatures, must be considered in working out a future automotive fuel policy. The alternatives to this as they appear in the light of present knowledge are then stated, including design considerations. The principles that should be followed to obtain as good results as possible with heavy fuel in the conventional type of engine are then described. These include considerations of valve-timing and fuel distribution. Valve-timing should assist correct distribution, especially at the lower engine speeds.
1920-01-01
Technical Paper
200052
O H ENSIGN
Continued lowering in the grade of fuel obtainable compels automotive engineers to produce engines that will utilize it with maximum economy. The manufacture of Pacific coast engine-distillate with an initial-distillation point of about 240 and an end-point of 480 deg. fahr. was abandoned by the principal oil companies early in 1920. Utilizing this fuel efficiently through its period of declining values forced advance solution of some fuel problems prior to a general lowering of grade of all automotive fuels.
1920-01-01
Technical Paper
200054
W S JAMES, H C DICKINSON, S W SPARROW
Supplementing a “more miles per gallon” movement in 1919, a series of experiments outlined by the S. A. E. Committee on Utilization of Present Fuels was undertaken by the Bureau of Standards, in May, 1920, which included measurements of engine performance under conditions of both steady running and rapid acceleration with different temperatures of the intake charge secured by supplying heated air to the carbureter from a hot-air stove, by maintaining a uniformly heated intake manifold and by using a hot-spot manifold, fuel economy being determined for both part and full-throttle operation. A typical six-cylinder engine was used, having a two-port intake manifold with a minimum length of passage within the cylinder block, an exhaust manifold conveniently located for installing special exhaust openings, rather high peak-load speed and conventional general design.
1920-01-01
Technical Paper
200041
H C MCBRAIR
The first car credited by the author as being equipped with two or more direct drives is the Sizaire-Naudin, in 1905. The transmissions of this car and of one embodying similar principles of gearing, brought out in 1909, are described and illustrated by diagrams. After the Sizaire-Naudin, the next double direct-drive transmission was the Pleukharp transmission axle, made in 1906, although the real ancestor of the present double-drive rear axles is the 1906 Pilain transmission; both are described and illustrated. Other early American and foreign forms are commented upon and diagrammed, including the Austin design, believed by the author to be the first to use a two-speed axle of the simplest and lightest possible type to provide two direct drives in connection with a separate gearset to give additional forward speeds and the reverse. Modern two-speed axles are reviewed, with critical comment and diagrams, and considerable discussion of gear ratios is included.
1920-01-01
Technical Paper
200043
F C MOCK
The adoption of the present system of feeding a number of cylinders in succession through a common intake manifold was based upon the idea that the fuel mixture would consist of air impregnated or carbureted with hydrocarbon vapor, but if the original designers of internal-combustion engines had supposed that the fuel would not be vaporized, existing instead as a more or less fine spray in suspension in the incoming air, it is doubtful that they would have had the courage to construct an engine with this type of fuel intake. That present fuel does not readily change to hydrocarbon vapor in the intake manifold is indicated by tables of vapor density of the different paraffin series of hydrocarbon compounds.
1920-01-01
Technical Paper
200046
HUBERT C VERHEY
The undisputed economy of the Diesel-type engine using heavy fuel oil is recognized, as no other power-generating unit of today shows better thermal efficiency. It is the result of the direct application of fuel in working cylinders. Transmission processes, such as the burning of fuel under a boiler to produce a working agent which must be carried to the prime mover, are less economical. The various factors which enter into a comparison between steam and heavy-oil installations are illustrated. The subject is treated in a more or less elementary manner. The diagrams and sketches are intended to explain the working principles of such examples of two and four-cycle engines as are now in actual operation in cargo ships, these being of the single-acting type. Double-acting and opposed-piston-type engines have been built and are being tried out. The working processes of two-cycle and four-cycle engines are illustrated and described in some detail, inclusive of critical comment.