Question to those with NA cars that track them:

Have you done any mods to the crankcase ventilation system?

At my last track day I blew a bunch of oil into the spark plug wells. I was really surprised because:

- I just built this engine in the fall and it has new valve covers on it for just this reason. Less than 1000mi on the engine.

- I have a Mishimoto catch can, again, for this reason.

When I pulled everything apart the catch can was effectively empty. I’m thinking that because the car is pretty much constantly at 4000rpm and up on the track, the PCV isn’t really working due to the low manifold vacuum and I’m getting a lot of pressure build up in the crankcase/heads, and it’s blowing oil past the plug well seals. The wells for cylinders 2 and 4 were dry, with 1,3, and 6 the most full…and also the 3 nearest the PCV (1,3) and the intake vent (6).

Has anyone else had a similar problem? If so, how did you fix it? I have another set of OEM covers and a new PCV on the way, but I’m skeptical at this point that the covers are the problem.

It’s a VQ35DE RevUp with C8 cams, running NA.

Thanks in advance for any help.

 

Haven't modded the PCV (yet) but had exact same problem twice on track days. I bought a new (cheap) set of valve covers and RTV'd the **** outta the gap between the well and plastic. No issue on the street (of course) but going to COTA next weekend so we'll see what happens! If I have issues I'm definitely doing something

 

Are you using the OEM PCV valve? If you are, you should replace it with a straight pass-through fitting like the one offered by Project Import (LINK HERE). I don't trust the OEM PCV valve under track conditions and since you already have an OCC, this won't hurt a thing.
Hope this helps
-Icer

 

Moroso catch can mounted up front, PCV drilled out and lines running to it from each valve cover.

 

I have VTA Breathers, i drive my car all the time over 4000 rpms for long periods, Ill smell a bit of oil from time to time.

 

Thanks for the responses, all.

It’s sounding like drilling out/eliminating the PCV valve is the way to go.

How do you have the ventilation routed? Currently I have:

Intake connection—> Rear of Bank 2 valve cover —> Bank 2/Bank 1 crossover —> PCV valve (to be drilled) —> Catch can —> Intake manifold.

Any need to change that routing? The CC doesn’t have a breather.

 

so you can essentially drill out the PCV valve or hollow it out to have it straight pass-through? the project import website doesn't list the price for theirs. I'm assuming its relatively cheap.

 

Just an update.

Based on the responses I decided to completely separate the PCV system from the intake tract.

- Capped the port on the back of the Bank 2 (driver) valve cover.

- Capped the port on underside the intake tube.

- Capped the port on the front of the plenum lower.

- Drilled out the PCV to ~.25”

- Replaced the line from the catch can “out” to the intake plenum lower (now capped) with a breather.

I also installed new OE valve covers and added the thinnest film of RTV to the plug well seals when installing. It’s vented to atmosphere now, so we’ll see what happens. I’m hoping to do some running this weekend, I’ll let you all know how it goes.

Thanks for the help.

 

I don't track mine, but that's almost the exact setup that I have when I went to the AdminTuning intake that does not have a port. Instead of capping off the port on the back for the bank 2 valve cover, I ran a line to an open breather dual input catch can. The other input is from the other valve cover where the PCV valve is.

 

Report after 7 sessions at Gridlife Chicago last weekend. Autobahn CC - South

Sessions 1-3 on day 1 were wet AF, not a ton of time way up in the rev range due to short shifting to dull the power, 100mph hydroplaning in braking zones, etc.

Sessions 4-7 on day 2 were dry. Much revs, many speed, such titanium, wow noise.

After action inspection: Breather filter was lightly oily to the touch, think older style K&N reusable filter after a fresh oiling. Catch can had minor filling. Plug wells are dry.

There’s a switch to a dual-feed catch can in the future for sure, but over the short term this seems to be working.

Thanks for the help, all. Looking forward to seeing to you out there on track.