Originally Posted by speed_demon24

With the stock PCV setup the crankcase is NEVER under vacuum.

Originally Posted by Mikey97Z

Actually, the crankcase is USUALLY under vacuum, since its air is being sucked into the intake.

But with a supercharger, the intake is sometimes pressurized.

Originally Posted by RIGRUNNER

I am not a genius but if a cranksace was under a vacuum you could hook your brake booster to the valve cover and be good. What is vacuum anyways? I think it is a lack of atomosperic pressure. It wont hurt it to have a lil vacuum but not to much or you make suck all the oil out of the motor. They do run vacuum pumps on cars the have a bit to much blow by. I.E. blower cars,turbo, high compression that are worn out!!!.

Originally Posted by speed_demon24

Hook up a vacuum gauge to the crankcase and show the gauge with the car running. No one has done this yet to prove me wrong... If its under vacuum its such an insignificant amount that it won't even register on a gauge.

Originally Posted by Injuneer

There is nothing wrong with vacuum in the crankcase. Ultra high performance engines often run a vacuum pump to maximize cranckcase vacuum. Helps stabilize the rings. Design of the system will minimize oil entrainment.

Have you hooked up that vacuum gauge to prove us wrong? And now were apparently changing the discussion to whether the vacuum is "significant".