CA488 four-stroke gasoline engine has four cylinders, the cylinder diameter is 87.5mm, the piston stroke is 92mm, and the compression ratio is 8. 1.

Compression ratio e=Va/Vc= 1+Vs/Vc, so combustion chamber volume VC = vs/(e-1) = 0.078l.

Because gasoline has low viscosity and rapid evaporation, it can be injected into the cylinder through the gasoline injection system, compressed to a certain temperature and pressure, and ignited by the spark plug to expand the gas to do work.

Gasoline engine is characterized by high speed, simple structure, light weight, low cost, stable operation and convenient use and maintenance. Gasoline engines are widely used in automobiles, especially small cars.

Engine is a machine that converts chemical energy into mechanical energy, and its conversion process is actually the process of working cycle. To put it simply, the fuel in the combustion cylinder generates kinetic energy, which drives the piston in the engine cylinder to reciprocate, thus driving the connecting rod connected with the piston and the crank connected with the connecting rod to reciprocate around the center of the crankshaft and output power.

The working process of a four-stroke gasoline engine is a complex process, which consists of four strokes (intake, compression, combustion expansion and exhaust).