INTAKE STROKE:

In this stroke the piston moves from TDC (top dead centre) to BDC (bottom dead centre) and the intake valve open. Because of this movement the vacuum is created in the cylinder. This vacuum sucks the air-fuel mixture inside the cylinder through open intake valve. In this process the crankshaft rotates 180 degrees.The intake valve remains open a few degrees of crankshaft after BDC. The intake valve then closes and the cylinder completely filled with air-fuel mixture.

Fig. Intake stroke

* Intake stroke

* Compression stroke

* Power stroke

* Exhaust stroke