Question

Describe the working mechanism of a four-stroke cycle engine.

Answer 1

1. Induction stroke; the piston moves down the cylinder; inlet valve opens; fresh air and petrol is drawn into the cylinder; Exhaust valve closed.
2. Compression stroke; the inlet valve closes, outlet valve closes; the piston up moves up the cylinder; this compresses: air fuel mixture in the combustion chamber;
3. Power stroke; a spark produced by the spark plug; this causes compressed fuel mixture to light and expand; resulting in pressure that forces piston down the cylinder; .
4. Exhaust stroke: piston moves up the cylinder, eliminating burnt fuel mixture through open exhaust valve;