[Bill Harris]

I know of someone who tried the two PCV deal, no breathers, etc on an engine on the dyno and lost serious power. The idea is that the PCV valves would make a poor-man's pan-evac, pulling a vacuum on the crankcase. Problem is that like it has been stated, PCV valve(s) is closed at WOT so the idea falls apart. Pressure builds in the crankcase and you lose power.

I have run with and without a single PCV with a breather on the opposite cover back to back. It made no difference except that I get less oil blowing out the dipstick tube when there are two open breathers than when there is one with the PCV. The pressure has to go somewhere, and no matter how well sealed the motor is, there is going to be blow-by.