The Gasoline Motor

The Project Gutenberg eBook, The Gasoline Motor, by Harold Whiting Slauson
THE GASOLINE MOTOR
BY HAROLD WHITING SLAUSON, M. E. Author of The Motor Boat
NEW YORK OUTING PUBLISHING COMPANY MCMXIII
Copyright, 1913, by OUTING PUBLISHING COMPANY
All rights reserved
THE GASOLINE MOTOR
THE GASOLINE MOTOR
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; and the burned gases resulting from this explosion must be ejected in order to clear the cylinder for the new charge. To accomplish this series of events, some motors require four strokes, while others do the business in two. These are popularly called four-cycle and two-cycle motors, respectively.
A cycle, of course, can be any round of events, such as a cycle of years—at the end of which time the previous happenings are scheduled to repeat themselves. But in gas engine parlance a cycle is taken to mean the round of events from, say, the explosion of one charge to the ignition of the next. Thus, it will be seen that the four-cycle motor requires four strokes of the piston to accomplish its round of events, and is, properly, a four- stroke cycle motor. Likewise, the so-called two-cycle motor requires two strokes to complete its cycle and should therefore be termed a two- stroke cycle motor.
If this longer terminology could be adhered to, there would be less misunderstanding of the meanings of two- and four-cycle, for when taken literally, these abbreviated forms signify absolutely nothing. Usage seems to have made them acceptable, however, and if the reader will but remember that four-cycle, for instance, means four strokes per cycle , the term becomes almost as simple as does four-cylinder.
It is evident that there are two strokes for each revolution of the flywheel—one when the crank is forced down and the other when the crank moves up. As the piston is attached to the crank through the medium of the connecting rod, the strokes are measured by the motion of the piston. Thus, since it requires four strokes of the piston to complete the round of events in the four-cycle motor, the explosions occur only at every second revolution of the flywheel. In this connection it must be remembered that we are dealing with but one cylinder at a time, for a four-cycle engine is practically a collection of four single-cylinder units.