Assignment

In the exhaust stroke, as much burnt fuel mixture as possible should leave the cylinder with very little loss (except in the case of internal exhaust gas recirculation).

Function

Like the induction stroke, this also lasts longer than a half a crankshaft rotation. It begins before bottom-dead center (BDC) through the opening of the exhaust valve and finishes at the end of the valve overlap after top-dead center (TDC). The burnt mixture is sent, as early as possible, to the exhaust system. Towards the end, the optimum speed of the spent gases should help to suck in the fresh gases. Once the fresh gases have filled the area up to the exhaust valve, this should actually close. This however, only functions completely in the RPM range of the maximum torque. Without special valve-lifting- or camshaft adjustment, below this RPM range the fresh gases turn back again, while above this range, too little gas is sucked in.

09/11