What is the working cycle of a gasoline engine?

[StSkylar]

The working cycle process of a gasoline engine consists of four strokes: intake, compression, combustion expansion, and exhaust. Below is the relevant introduction: Intake stroke: At this time, the piston is driven by the crankshaft to move from the top dead center to the bottom dead center, while the intake valve opens and the exhaust valve closes. When the piston moves from the top dead center to the bottom dead center, the volume above the piston increases, the gas pressure inside the cylinder decreases, creating a certain degree of vacuum. Since the intake valve is open, the cylinder is connected to the intake pipe, and the air-fuel mixture is drawn into the cylinder. When the piston reaches the bottom dead center, the cylinder is filled with fresh air-fuel mixture and the exhaust gases left from the previous working cycle. Compression stroke: The piston moves from the bottom dead center to the top dead center, with both the intake and exhaust valves closed. The crankshaft rotates under the inertia force of the flywheel, pushing the piston upward through the connecting rod, gradually reducing the gas volume inside the cylinder. The gas is compressed, and the pressure and temperature of the air-fuel mixture inside the cylinder increase accordingly.