With a Boosted motor what is the most efficient way to releave crankcase pressures. Is the OEM design PCV system efficent enough for 8,9,1000+ HP?

I had a discussion with my step dad about welding a 3/4" bung into each valve cover and then routing each side with- 12 line to their own breather tanks. He said that wouldn't be enough. You'd need 2 bungs per side and a total of 4 -12 lines to 4 breather tanks to be efficent. I think that is way overkill and a big waste of resources. If thats the case might as well use a vacum pump. What should I do?

 

There was a thread discussing this not long ago, aparently without a definite ultimate solution.

https://www.thirdgen.org/forums/powe...crankcase.html

 

Very interesting thread. Still no solution.

 

Sounds like the check valve in the PCV hose would be ample. I mean, with the exeption of a boat application, you won't be under boost for very long anyway. For those few seconds per minute, your not going to do much harm to the oil. If oil leaks are a problem, you should fix them anyway. ' just an opinion

 

Personaly my motor hasn't seen any street duty, just 40 pulls on a engine dyno with no leaks to report. My concern is when the car is in shape to drive on the street I don't want the crankcase pressure to cause a leaky motor, especially all over the top half of the motor(showcar).

 

Sending the pcv back to the tb like the factory did will put oil into your intake. Even the best check valve will let some by. Oil in your tb/intake/ intercooler will cause a host of problems.

I ditched the pcv line used a set of breathers in each valve cover andnever had a problem. The oil drain back holes at the ends of the heads are more than large enough to relieve the pressure.

JMO HTH!

 

What kind of Boost and HP are you making?

 

car is sold but it ran a 12.7 on 15-18 psi (wasn't steady) and the turbo didn't even get into it's efficiency range until 22psi or so.

Weight was 3655

Calculator shows 500 at the crank 430 at the wheels.....

Not to shabby for a 231 V6

 

I posted this question on another board and a LT-1 owner showed some promising photos of the Mr.Gasket Evac system with the owners own flare. He says it holds good vacum at idle and just gets better with RPM. Check it out.

Boost and cranksase ventilation. - Page 3 - CamaroZ28.Com Message Board

 

My theory has always been PCV going into the intake is bad. It increases air temperature which makes it more prone to detonation. I would think it would increase the likelyhood of fouling plugs.

You need as much crankcase vacumn as you can get. Crankcase vacumn promotes ring seal, giving you less leakdown, and less blowly which in turns gives you less pressure in the case. Kinda ironic.

What I am going to do, is hook each valve cover to a hose and put it downstream in my downpipes. The vacumn from the exhaust gases flying by SHOULD create a vacumn in the crankcase. Its a theory thats worked in some of the VW's I have worked on. We'll see what happens when I put it to the test on my camaro.

This is all stuff thats been discussed. *Shrug*