Thread: Crank Case Ventilation fully explained. (Turbocharged edition.)

Looks a bit overkill for our engines, but that's a tough call to make. You're also potentially bypassing baffles in the valve cover simply to add baffles in the form of the catch can.

You would still want to have the smaller PCV line hooked up to the plenum of course.

Would it help to remove the restrictor fitting in the intake to match the -10AN hose size?

Here is how I did mine. -8 fittings welded onto the valve cover and one onto the block breather on the front of the motor. I connected the two fronts as normal using 1/2 aluminum hardline with -8 AN fittings. Then the two other ones, one where the pcv and the other where the breather to the intake pipe, now go to the catchcan also using 1/2" aluminum hardline w/ -8 fittings. My original plan was to do 4 breathers to a can located where the distributor was but since I had to go back to the distributor I went this route instead.









The motor had very very little blowby even at 29 lbs of boost and 700+whp so I really had no need for 4 breathers anyways.

That's how I am setup currently for the most part. Everything is vented to a crankcase breather. However, from reading this thread this seems to be the improper way to do it.

For smaller setups yeah its not the proper way to do things but for large turbo setups that need maximum crankcase ventilation this is the proper way to do it.

I also wanted to add...

Couldn't you just delete your PCV valve and install fitting, cap the intake manifold, and put a hose to the sealed catch can along with the hose from your T fitting on the drivers side?

I noticed when I run no PCV valve I have a perfect idle. I've tried 5 different valves and have never had one that didn't cause some sputtering and lower vacuum at idle.

ok i just blew my turbo, i think it might have to do with having to much pressure in the crankcase and also the wastegate line being pinched and boosting 15psi without wanting to. Now im hoping(praying) the engine isnt screwed, so while im out rebuilding/buying another t25 jb, im going to hammer out the dents in the oil pan and weld a nipple on my intake pipe after the maf and tee off from the crankcase t to that nipple and putting a one way check valve so boost wont pressurize the crank case, would this be a good set up. Im also trying to see how i will try and keep oil out from the intake track, my friend mention a linear filter i can try or maybe another catch can, i just dont want to blow another turbo and i want a good way to release crankcase pressure i dont really care if its a mess under the hood either, its a daily for work and school, any suggestions?

No, I would retain both factory restrictors under most circumstances.

I will respectfully disagree. However, drag cars really can do whatever the hell they want and there will be little consequences.

I've finally added another example of modification for this (the most common modification, which is to add another catch can). I want to add more, but we'll see as time permits.

NVM...