Thoughts on venting the oil return line, another possible smoke fix?

[bnoon]

Some of you may know that my project car is a 1980 Porsche 924 Turbo (931). While researching rebuilding techniques/tricks for my 931, I came across a crankcase breather recall/update for the early cars. My car has this update on it and it got me thinking... Seems Porsche had an issue getting too much crankcase pressure on the oil return of the turbo, causing it to blow oil past the turbo seals. Sound familiar??? Here was Porsche's fix, note the little box in the oil return line:



Here again in a smaller pic that you can see the line coming out of the top of the box.



Note the little "box" in the return line, and the hose/tube routing out of the top of that box. That upper tube/hose is vented into the top of the head to help equalize the pressure buildup, here:



What I am proposing is a similar fix, but rather than venting the return line to the head or valve cover, I'd run a hose/tube up the back of the block, put in a second PCV valve there and run some hose across the top of the engine and back down the front to a T-fitting near the stock intake manifold PCV hose connection and/or catch can location.

[Nataphen]

I don't know if it would fix it, but it's a pretty interesting thought. Maybe you should work for Mazda's design team.

[YokiMazoku]

So any update on this im interested as to see if it actually would work or not.

[tddvrrn]

i was scouting for possible catch can sites today and noticed some space under my sri. you could easily route a line there from the back of the engine as well as from the pcv under the manifold.. where were you thinking of venting the block?

[bnoon]

Originally Posted by tddvrrn i was scouting for possible catch can sites today and noticed some space under my sri. you could easily route a line there from the back of the engine as well as from the pcv under the manifold.. where were you thinking of venting the block?

No, not venting the block. And you wouldn't need to run to the SRI side of the PCV system, you'd just need to run a line from the oil return line to the PCV valve location under the intake manifold and "T" it in there..

[Lex]

Seems like a good idea - especially for higher mileage motors.

Get some pics of the 931 up. I have a 1986 951 as a project car

[triplejumper18]

In before PTP "designs" this fix.