Never had one in a race motor. Street engine that gets miles put on it is a different situation.

A vac-u-pan system with clear hose tells you exactly whats going on in the engine moisture wise. Or in the puke tank if you're using a vacuum pump. Or pull a breather and look at it for milkshake. A problem will show up there before you see it on a dipstick.

If the results don't match the theory, change the theory.