Question

Explain the following stages in the working cycle of an internal combustion engine.
a) Intake stroke
b) Power stroke.

Answer 1

Intake stroke : The piston moves away from the cylinder head.

• Low pressure is created inside the cylinder and the inlet valve is opened.
• The fuel mixture from the carburettor enters the cylinder.
• The outlet valve is closed.

Power stroke :

• The compressed mixture is ignited by the sparks produced by the spark plug.
• A lot of heat is produced by the combustion.
• The products of combustion carbon dioxide and water vapour expand suddely.
• The piston is pushed with great force. Both inlet valve and outlet valve are closed.