Assignment

The combustion stroke should provide an early and rapidly increasing combustion pressure in the completely sealed combustion chamber, which is then transferred to the crankshaft through the pistons and the connecting rods.

Function

It actually begins during the compression stroke, when the fuel is injected (Diesel engine) or when the electric spark ignites the air-fuel mixture (petrol engine). At idling speed, this occurs mostly just before TDC, and at higher revs, at around 30° (Diesel engine) or 60° before TDC (petrol engine). The greatest increase in pressure occurs, in all cases, after TDC. The performance obtained must be substantially higher than that rendered in the other three strokes. 09/11