Thought I'd ask how other people have gone about the PCV delete on the Subaru's. Running an EG33 and I'll admit I took the sledge hammer to it.

Ran block offs everywhere. Cylinder heads etc, but after a few runs its been pretty clear that I'm seeing significant crankcase pressure and the catch can is filling up. Comp test is good and in general leakdown seems OK so at this point I am calling this reasonable leakage (pending results of further runs). After and hour or two of punishment I was seeing no less than 250ml leakage with blocked off head PCV oil exit ports and crankcase plumbed to catch can, which seems excessive. performance and general stats were good.

I thought I would ask, is there a better way of setting up the PCV Delete, maybe equalizing between left and right heads by installing a bridge hose between the two heads? I notice this is how it is setup on the later turbos.

If the results continue to be good, I'm thinking of plumbing the drain of the catch can to the sump with some type of filter/ air/ oil separator configuration.

Does anyone have experience with this, is there a general consensus for how this should be done?

 

Do a google search for the PCV routing for the WRC/Grp-A/Grp-N Subarus that was designed by Prodrive and copy theirs.  No oil catch can required, simple VTA setup.

Thanks, I followed my original plan which is mostly the same I think, breather on top of catch can. I am running a Smallcar low profile pan that doesn't have a terribly clear oil level indication system. After a few more follow-up runs didn't have anywhere near the same level of oil getting caught. Get the feeling that the engine was just dumping some excess oil. 

You wasted money by including a catch can in your PCV system.

For those looking to modify your PCV system, this thread lays out the routing that Prodrive developed for early GC/GD WRC cars.  Don't spend a dime on a catch can.  It's just another item to maintain and you don't want that oil going back in your engine anyway, now that it's full of moisture.

I think you will find most race orgs call for a catch can as an environmental thing so you aren't spewing oil over the ground. This is why I got the catch can in the first place. I do think you are right about circulating back to the engine being a no go. The small amount of overflow I had been getting on concurrent runs was contaminated. Just empty the can occasionally and call it job done.

On ‎3‎/‎1‎/‎2019 at 11:30 PM, rotamonkey said:

I think you will find most race orgs call for a catch can as an environmental thing so you aren't spewing oil over the ground.

That's as good a reason as any to run a catch can.