THE TWO-CYCLE MOTOR.
Although the four-stroke cycle type of motor is used by most of the automobile manufacturers, yet there is another type which has given such good results that it is destined to become one of the important forms to be used in gas engine vehicle manufacture.
Fig. 39.
It therefore merits a brief description. It has the advantage of being very simple in construction and operation, and for this reason it has become very popular among the marine engine builders, although with a few exceptions it has not as yet been accepted by motor car engineers. It is called a Two-stroke Cycle Motor, so named because it combines in two strokes the series of changes ordinarily accomplished in four in the four-stroke cycle type. Its operation may be seen by referring to the accompanying diagrams. It is first assumed that the engine is being turned over by hand in the direction indicated by the arrow. You will note that as the piston moves up it will uncover a port (H), allowing the gasoline vapor from the mixing chamber to enter the crank case. As soon as the piston moves down again, a port (J) will be opened, allowing the mixture which has just been compressed to rush through a “by-pass” (F), into the “combustion chamber,” or upper part of the cylinder. Now, as the piston moves up again on the next stroke, this charge is compressed still more, then as the piston reaches its uppermost position the charge is ignited and the engine begins to work under its own power. The gases continue to act on the piston until nearly the end of the stroke is reached, when you will notice, by referring to the drawing, the exhaust port (G) is passed. At this point the burned gases rush out into the air. You will also notice that in order to aid the discharge and fill the cylinder again, as the piston travels a little farther down, the inlet port will be again uncovered, and the next charge, which has meanwhile been taken into the crank case and compressed, will enter the cylinder, forcing the exhaust gases out.
Fig. 40.
In order to prevent the vapor which has just entered the cylinder from traveling straight across and out through the exhaust port, thus wasting a portion of the fuel, a “baffle plate” (K) is cast on top of the piston which deflects the gases toward the top of the combustion chamber, producing a sort of whirling action which tends to scavenge the cylinder most thoroughly. In order to prevent the burning gases from traveling back into the crank case and igniting the gas there, thus producing a “back explosion,” a wire gauze (S) is placed in the “by-pass.” You will note that this type of motor has no valves, no cams and no cam shaft, in fact, its simplicity is such that it practically cannot get out of adjustment. It therefore is a form of gas engine which as soon as engineers are able to educate the public to its peculiarities bids fair to become as popular and practical as the four-stroke cycle.
INDEX
| Cam shaft | [21] |
| Cam | [20] |
| Carburetor | [28] |
| Commutator | [33] |
| Connecting rod | [26] |
| Connecting rod—lubrication of | [26] |
| Cooling system | [37] |
| Crank case | [27] |
| Crank shaft | [25] |
| Cycle—explanation of four-stroke type | [9] |
| Cycle—explanation of two-stroke type | [42] |
| Cylinder | [16] |
| Electrical ignition | [31] |
| Exhaust valve | [21] |
| Fan—radiator | [39] |
| Float chamber | [28] |
| Gasoline valve | [30] |
| Ignition | [31] |
| Induction coil | [32] |
| Inlet valve | [21] |
| Piston pin | [24] |
| Piston ring | [24] |
| Piston | [23] |
| Pump—water | [38] |
| Radiator | [39] |
| Spark plug | [35] |
| Switch—electric | [36] |
| Valve grinding | [21] |
| Valves | [19] |
| Valves—mechanism | [21] |
| Water cooling system | [37] |
| Water pump | [38] |
| Wiring diagram—four-cylinder | [34] |
| Wiring diagrams—single-cylinder | [32] |