What is the difference between two-stroke and four-stroke gasoline engines?

[LeHope]

Introduction to the differences between two-stroke and four-stroke gasoline engines: 1. Difference in valve mechanisms: A four-stroke engine transmits the rotation of the crankshaft to the camshaft via a timing chain. During the rotation of the camshaft, the intake and exhaust cams push the rocker arms to swing, and under the action of the valve springs, the intake and exhaust valves open and close at the right time. In a two-stroke engine, the air-fuel mixture entering the crankcase controls the opening and closing of the intake and scavenging ports through the movement of the piston under a certain pressure, completing the scavenging and exhaust processes. 2. Difference in lubrication methods: The piston-connecting rod mechanism of a four-stroke engine uses a crankshaft splash lubrication method; the camshaft, rocker arms, valves, etc., use a pump-pressure lubrication method. Two-stroke engines generally use either a mixed lubrication method or a separate lubrication method. In the case of the separate lubrication method, the crankshaft-connecting rod assembly in the crankcase, the cylinder, and the piston assembly are all lubricated by a mist-like mixture of *oil, gasoline, and air. The lubricating oil plays the roles of lubrication, cooling, sealing, and cleaning in the engine, affecting the wear of parts and their service life. 3. Difference in combustible mixture composition: A four-stroke engine uses a combustible mixture composed of gasoline and air. A two-stroke engine uses a combustible mixture composed of gasoline, oil, and air.