Compression and Engine Life...
 

How much does the compression ratio of a race engine effect its life?

Let's say you have a 964 3.6L engine with stock pistons (measured at 10.8:1) and the rev limiter set at 6800 RPM. Comparatively, how long would that same engine last in a race environment if you went to 12.5:1 on the compression ratio with the same rev limit?

The same? 90%? 70%?

Scott

I would tend to think more like 90%. It will make more torque and stress everything more, but the real stresses arise with rpm (unless you are seriously bumping compression or using a turbo).