Effect of Some Piston Variables on Piston and Ring Assembly Friction

The piston and ring assembly friction of a lightweight piston with lower compression height has been compared to that of a production assembly. Additional weight was added to the lightweight piston to study the effect of that variable alone.

The lightweight piston reduced friction, especially in motoring tests. Within the speed range tested (up to 1640 rpm) the friction reduction of the lightweight piston could not be attributed to the lower mass itself.