As a kid I was always told: Suck-Squeeze-Bang-Blow!
Induction, Compression, Expansion (or Ignition), Exhaust
- As the piston is drawn down, the inlet valve opens and fuel mixture is drawn in with fresh air. (with turbo engines, it's pushed in)
- Piston rises and the inlet valve closes compressing the gases
- Around tdc the mixture is ignited (spark - Petrol or by the heat caused during compression - Diesel) and the piston is forced down by the expanding (ignited) gases
- Piston rises and the exhaust valve opens to allow the burnt mixture to be forced out.
