I've been looking at the pics of several people's engines here.. and I have made the same mistake as a lot of you people.

This has to do with venting the crankcase and it's ability to breathe properly.

There are 2 connections on the valve cover.. at no time should either of these see boost..

I know a lot of people when boosting say they need a "catch can" to trap the oil blowin out the side vent in the valve cover i think this is partially due to the pressurizing the crankcase.

The one on the end of the engine (cyl 4) is a vacuum inlet, and the one on the top of the engine (cyl 2) is the PCV gas outlet..

One is bigger than the other for a reason.. if the crank case pressure gets to high, the smaller tube is more restrictive and combinied with vacuum from the engine and the larger tube, it pulls the pcv valve open.. allowing air to come in the small tube by #4 and then the gasses to vent out the large tube above #2.

Both these connections should be routed before the turbo in the intake piping. I'm gonna look at a valve cover in a while to see if we can baffle the "inlet" to help prevent oil from pooling and spilling out during hard cornering.

Opinions and other ideas are welcome.

-- WheatKing

i have my breather vented to atmosphere, with a second checkvalve in line with the pcv. The problem with the stock PCV is that is leaks, especially if it is trying to hold back more than a few lbs of boost. The second check valve in my PCV line basically closes if any boost pushes on it, but any pressure from the crankcase will open it and allow the system to breathe.

I never get blowby, unless something breaks in my bottom end. I've enver had a catchcan, because i've never needed one.

MSG me on AIM when you get a chance, Dave.

Dino, that's a great setup. Where do you get a check valve like that?


95 Eclipse RS : 5 speed
Jeep TB writeup - http://www.dimensia.com:81/jimbo/JeepTBfor2gnt.html

Autozone. it's a big 90* brake vacuum reserviour check valve. It was in the "HELP!" section.

YEah, I'm interested as well. I know when I had my car on the road last season, I was leaking boost somewhere. If I do this, then I know it's not at the PCV........thanks once again Dino!

ok i have a question? the tube going from the BOV to the manifold is suppose to replace the factory one on there right? but i did not have any blowby when i had it t tapped into the BOV tube. now that i do not have it t tapped i am getting oil in the air filter. i thought that it was the pcv but i am still getting it. so i am going to try this again and see what happens.

I have both of those routed to my catchcan. The PCV valve is still in there though. I do get liquid in my catchcan though. It's not oil blowby but it's a clear liquid. I think it's either gas or water condensation.

So they are both still able to breathe but they just aren't getting sucked back into the intake.