At the end of the stroke, the availability of a spark plug allows the ignition of the air-fuel mixture, providing the energy required for the combustion. The piston moves up the chamber, making the air and fuel compressed. Compression stroke : at this stage, the intake valve is closed, blocking the air-fuel mixture from escaping.intake/inlet stroke : this is the first stage of the combustion cycle at this stage, the piston moves downward in order to allow the fuel and air to enter the chamber.
That is, all these processes must be accomplished before a vehicle can move. The following explained below is the combustion cycle of the four-stroke engine.
