Engine power

“ The chief advantage of this "composite" system of power transmission is that the engine is kept running at a constant speed, while the power it develops at the electric motors is regulated by switches which control the action of the armature and field magnets. When heavy work must be done the engine is supplied with more gaseous mixture, and the generators are so operated as to develop full power. In this manner all the variable speed gears and clutches necessary when the petrol motor is connected to the driving-wheels are done away with. ”

“ Most of the evolution of gas engines has consisted merely of the improvement and perfection of the various parts for more power, and more all around efficiency.
"You remember what you found out about gasoline motors in general when we were spending so much time talking about aeroplanes. The high speed motor, as we know it now, was invented, you know, by Gottlieb Daimler, a German inventor, in 1885, and with the ordinary four-cycle engine it takes four trips, or two round trips of the piston rod, to exert one push on the crankshaft of the engine. ”

“ Again, on the compression, suction, and exhaust strokes, the piston has to be pushed or pulled by some means, as no power is being generated. Therefore, if the engine is to be self-acting and run continuously, some means must be provided for storing up the great force of the explosions and giving it out again on the idle strokes. ”

“ The power that a gasoline engine is capable of developing depends on the size of the cylinder, the pressure acting on the piston, and the speed at which it operates. A steam engine, which obtains its pressure from a boiler, can do work as soon as the steam is turned into the cylinder, but a gasoline engine must be running before it can be called on to deliver power. ”

“ Fig. 42. Progressive Transmission. Low.
Economy of Transmission Gearing.—From an economical standpoint, also, it would be undesirable, even though the engine should be able to make the speed.
Owing to the explosion impulses of the gasoline motor, a heavy fly wheel is necessary on the engine shaft, in order to store up power by momentum, and also to give a uniform speed.
In hill climbing, or in carrying heavy loads, (71) the transmission shaft must have its speed cut down, while permitting the engine to run at full or normal speed. ”

“ When the engine is working at its fullest power at maximum speed these apertures correspond, and consequently the largest amount of mixture passes to the combustion chamber. When, however, the work lightens and the engine begins to race, the governor comes into operation, and the holes in the plunger and plunger slide eclipse each other to a greater or lesser degree, according as a greater or lesser quantity of explosive mixture is required.
The system is more economical of petrol, and gives smoother running than governing the exhaust valves. ”

“ In this respect it is unlike the steam engine, which has a much wider range of effectiveness. Since all cars now use internal combustion motors, and throttling is unsatisfactory, as a means of controlling the engine, or changing the speed and power, so as to use it economically, a mechanical speed change system is essential. ”

“ The engine itself requires no absorbing area, as I want to use it; it takes advantage of the fact that the Earth is absorbing quintillions of horsepower. I have merely tapped the power that the Earth has already absorbed for me. Come here.”
He led the way down the corridor to his laboratory, and switched on the lights. On the main laboratory bench was set up a complicated apparatus of many tubes and heavy bus bar connectors. From the final tube two thin wires ran to a long tubular coil. To the left of this coil was a large relay switch, and a rheostat control. ”

“ The "jet" carburetter, now generally employed, makes the mixture more positive by atomising the spirit as it passes through a very fine nozzle into the mixing chamber under the suction from the cylinder. On account of their small size spirit engines work at very high speeds as compared with the large oil or gas engine. Thus, while a 2,000 h.p. Körting gas engine develops full power at eighty-five revolutions a minute, the tiny cycle motor must be driven at 2,000 to 3,000 revolutions. Speaking generally, as the size increases the speed decreases. ”

“ The company is now building cylinders giving outputs of from 1,200 to 1,500 brake horse-power per cylinder, giving outputs of from 5,000 to 6,000 horse-power in tandem twin type engines. As will be seen from the cut, the horizontal Diesel engine is remarkably free from complicated valve gear. ”

“ Formerly, the power to drive a machine was derived from a very complicated arrangement of shafting and gearing brought from a distant engine. But by my system I conveyed the power to the machine by means of a steam pipe, which enabled the engine to which it was attached to be driven either fast or slow, or to be stopped or started, just as occasion required. It might be run while all the other machines were at rest; or, in the event of a breakdown of the main engine of the factory, the small engine might still be kept going or even assist in the repairs of the large one. ”

“ Indicated Horse-Power.—The horse-power which an indicator would show as being developed inside the cylinder of a petrol engine, above the piston, would be called the indicated horse-power, and should always work out a greater number than the brake horse-power or power available at the engine flywheel, because some of the power liberated from the combustion of the petrol within the cylinder is lost in friction of the piston and bearings. ”

“ Incident to this is the advantage of subdividing power units in a large plant: each motor may receive its gas in pipes without loss, to be operated at will. The rapidity of flame propagation renders possible a high number [465] of shaft rotations per minute, so that a multi-cylinder engine weighs little in comparison with its power. ”

“ Transmission came into use with the application or adoption of the internal combustion engine as a factor in motor car propulsion.
As this type of engine develops its power by a rapid succession of explosions in the combustion chambers, each explosion delivers an impulse or power stroke to the piston, which in turn sets the crank shaft and flywheel to revolving. The momentum gathered by the crank shaft and flywheel may therefore be termed the power for duty, or in other words, unless there is momentum or carrying motion at this point, there will be little or no power for duty. ”

“ As an engine’s power varies directly as its speed as well as its cylinder capacity or size, an engine commonly used for ten horsepower would become a twenty horsepower engine if the speed could be doubled. So high speed engines are very small and compact, and require less metal to build them. Therefore they should be much cheaper per horsepower.
A high speed engine differs from a low speed in no essential particular, except the adjustment of parts. A high steam pressure must be used ”

“ In the four-cycle type of engine, which is in almost universal use for automobiles, the events are considered with reference to the movement made by the piston during which they are performed, and may be called the inlet, compression-combustion, power, and exhaust strokes. In order that the engine may continue to run, it is obvious that the events must be performed in the correct order, and that the failure of one will affect all the others. ”

“ As everyone is aware, it furnishes the favorite type of motor, combining extraordinary power with relative lightness, and making it feasible to carry fuel for a long journey in a receptacle of small compass.
With the gas engines a complication arises precisely opposite to that which is met with in the case of the cylinder of the steam engine—the tendency, namely, to overheating of the cylinder. To obviate this it is customary to have the cylinder surrounded by a water jacket, though air cooling is used in certain types of machines. About fifty per cent. ”

“ The gasoline engines that were used in these tests are representative of the standard American stationary-engine types, rating at 10 to 15 horsepower, at speeds of from 250 to 300 revolutions per minute, while the alcohol engines were of similar construction and identical in size with the gasoline engines. ”

“ Motor and Propeller
(Detroit Aeronautic Construction Co.)
Possible progress in weight economy is destined to be limited by the necessity for reserve motor equipment.
The engine used is usually the four-cycle, single-acting, four-cylinder gasoline motor of the automobile, designed [Pg 109] for great lightness. The power from each cylinder of such a motor is approximately that obtained by dividing the square of the diameter in inches by the figure 2-1/2. Thus a five-inch cylinder should give ten horse-power—at normal piston speed. ”

“ It has but one weak point, its cylinder, and but one delicate structure, its carburetter; while the steam engine has numberless sources of injury in its boiler, its tubings, its pumps, its cylinder-heads, &c., which are simultaneously subjected to extreme pressures, due both to the steam and to violent jolts on rough roads. Besides, to make a one-horse-power hour with a petroleum motor requires about 0·750 kilo of oil, and since the invention of the radiator or surface-condenser, the same water can be used indefinitely for cooling the cylinder. ”

“ As a matter of fact the whole power of the engine is never available for the work of turning the wheels of the car, a certain portion of it always being absorbed in the work of driving the gear; indeed, it is not too much to say that in some instances—as has indeed been proved by actual tests—fully one half of the power developed by the engine is thus lost between the motor and the wheels. ”

“ Steam at a very high pressure enters the high-pressure cylinder, expands and escapes at a lower pressure into a larger cylinder where it again expands and does more work. A compound engine is more economical in steam than a simple engine, and therefore requires a smaller boiler to develop the same horse-power, so that when we consider the weight of water and fuel for a given time, together with the weight of the boiler and the engine, the engine motor with a compound engine is lighter than a simple engine. ”

“ In both engine and turbine the real source of power is not the steam but the fuel, such as coal or oil, which converts the water into steam.
180. Gas Engines. Automobiles have been largely responsible for the gas engine. To carry coal for fuel and water for steam would be impracticable for most motor cars. Electricity is used in some cars, but the batteries are heavy, expensive, and short-lived, and are not always easily replaceable. For this reason gasoline is extensively used, and in the average automobile the source of power is the force generated by exploding gases. ”

“ Types Of Motors There are certain events that must happen in a gasoline motor before the engine will run of its own accord. For instance, to obtain successive power impulses, the charge must first be admitted to the cylinder and compressed; it must then be ignited to form the explosion that creates the force at the flywheel ”

“ It has also been shown that the quantity of water evaporated, whatever be the pressure of the steam, will be in the direct proportion of the quantity of heat received from the fuel, and therefore in the direct proportion of the quantity of fuel itself, so long as the same proportion of its heat is imparted to the water.
(136.) The POWER of an engine is a term which has been used to express the rate at which it is able to raise a given load, or overcome a given resistance. ”

“ By this I mean that the means of transmission may be so altered at will that whereas when on level ground the engine may make, say, only two revolutions to each one of the road wheels, for hilly or heavy work it may make, say, four, six, or eight, and so, whilst the car travels slower, the engine speed may remain the same. Where steam engines are used this is not usually required, as the steam engine obtains more power for heavier work by the use of more steam. ”

“ The type of engine that will give satisfaction depends on the work that is demanded of it, the care that it will receive, and the knowledge of the operator. A one-cylinder engine, having a minimum of parts, may be successfully managed by a novice, but its vibration, and the fact that it delivers power for only one fourth of the time that it runs, make it unsatisfactory for any but light work. ”

“ With a gasoline engine, however, the conditions are very greatly altered. Here the engine constitutes practically the entire weight of the power plant, only such accessories as the ignition coil, batteries, and carburetor being available for lowering the center of gravity, unless the fuel, cooling water tanks and radiator be placed below the engine and the liquids forced up by means of a pump. ”

“ The motors are so light that they develop two horse power for every pound of their weight; while, to keep the frames thin, the necessary power is obtained by terrific speed of the moving parts, as though a steam engine, to avoid great pressure in its cylinders, had a long stroke and ran at great piston speed, which, however, is no disadvantage to the rotary motion of the electric motor, there being no reciprocating cranks, etc., that must be started and stopped at each revolution. ”

“ It's the coming power"—Matt's gray eyes brightened enthusiastically—"and as motors are improved, and their weight reduced in direct ratio with the increase in the horse power, the explosive engine will be used in ways as yet——"
"That's all right," cut in Murgatroyd, who was coldly commercial and as far removed from anything like enthusiasm as night is from day. "A gasoline engine is a noisy, dirty machine and smells to high heaven. ”