Possible crankcase pressure problems???
 

Hi all. I’ve Recently had a bottom end built of a 1.6 with cp pistons and some rods. New rings bearings etc. having a problem where turbos are leaking oil from the compressor side. Had a precision 5557 on there at first and it was leaking bad. Rebuilt it. Same thing happens. Bought a cheap cx racing turbo. And it’s still leaking from the compressor side. Drain and feed lines are completely vertical. Stock Pcv system was replaced with a catch can. Also no oil in the exhaust port of the head. That’s my reason for thinking crankcase pressure is to high. And not allowing oil to drain properly. I’ve attached a picture to sort of be able to see catch can setup. -10an fittings welded on the front right side and rear left side.I can take a better one after work. Any insight would be appreciated. Thank you.
https://cimg4.ibsrv.net/gimg/www.mia...0ff1f7362.jpeg

Restrictor on oil feed line? Are you sourcing oil feed from the block?

Sourcing from the block and restrictor on the precision was 30 thousands and the cx turbo is slightly bigger.

Is the catch can vented to atmosphere?

Catch can is not vented. But I did remove hoses from the valve cover. And it still did it but it could’ve been residual build up

Step 1 vent catch can

Even at just idle it does it. would not having a vented setup make that much of a difference. The car hasn’t seen any rpms above 3000 yet. No boost. Hasn’t even been driven. Been trying to figure this problem out for the last month. Finallly figured I’d just ask here and see if anybody knew.

If both hoses go to a closed container, that's exactly the same as capping off both hoses at the valve cover.

Please tell me you understand this.

Six i understand this completely is a basic concept :bang:

You get it and I get it but I'm not sure about xmac.

So to sum this up you capped off the only routes for crankcase pressure to escape and now you don't know why you have excessive crankcase pressure?

Umm...

Na I understand I’ve seen setups similar to this before with no breathers that have worked before. Think I’m gonna do a dual setup and put a breather on each. Hopefully that works.

https://cimg8.ibsrv.net/gimg/www.mia...69a649ff5d.png

No you havent seen sealed setups that have worked before.

This is a simple concept. Cap off vent on the pcv side. Run big line from exhaust side into a VENTED can. Drill out the passage in the valve cover and add copper scrubbers. Then be done with it.

Or just run both sides to a vented can.

The secret is not a secret. It's the venting part. Engines need venting. Even Briggs & Stratton have venting. You have never seen an engine without venting. Ever. You might not have understood where it was venting, but it was venting.

there's 2 options:
1) sealed with 2 ports, one of them to a vacuum source
2) vented

das it

Alright I’ll try that thanks

The OEM standard for dual catch can is back to the vacuum source, while the PCV and IM takes it to non vented catch can

http://www.radiumauto.com/Catch-Can-...ata-P1180.aspx

Those setups that you've seen without a breather filter have an additional line that is routed to the intake piping before the turbo, and it dumps the crank case pressure there. Nobody runs theirs set up the way you have it, because it doesn't work.

This is my dual catch can setup

Passenger side: PCV bung tapped for hose fitting (prevents weeping leak) -> Catch can -> Hose to PCV valve -> Another hose to Intake port from PCV -- This puts the PCV inline between the catch can and the intake manifold. Prevents pressurizing the catch can and keeps a large ID for the vacuum hose to slow airflow
Driver side: Valve cover port --> Catch Can -> Port on filter @ turbo

https://cimg5.ibsrv.net/gimg/www.mia...f7955aaa08.jpg