Im going to modify my CCV, need advice (Long)

[JoeDellio]

I have excessive pressure from cylinder #1 testing out at 170-180 psi when all the others are 225, and its pushing oil out of the cap because the CCV cant keep up with it. The car runs GREAT, so a new engine is outta the question if this can let her roll out some more. Its got 250K on it and I wanna push it to the limit.

The CCV pulls a slight vacuum of 10-15mbar when the throttles closed. Too much vacuum will suck air through the seals, but I want to try and bump it up to 18-20 and see if that helps rid of some more pressure.

The brand new OEM CCV I have isnt gonna cut it.

First I am going to throw a vacuum gauge on the CCV line and see what its actually pulling, it could just be getting gunked up with oil real quick and not doing its job, because it works for about a week after a cleaning.

Im gonna get rid of the CCV all in itself, or gut it if I have to so its free flowing. Then Im gonna get an inline one-way valve, with a one way bike fuel filter before it to act as a catch can between the valve cover and intake. Im then gonna tap the vacuum gauge back in and leave it there permanently and adjust the valve to pull my 18-20, or until no seepage occurs.

Heres are my thoughts: Would a one way valve be the way to go? I dont want any pressure to go back in, but will vacuum still pull from the other side of the valve then? I would think so, but I dont know. I just thought the oneway would be easier to get a solid number for a reading.

Another thought is could all my seepage just be coming from my driving when on the gas? Because then the vacuum stops pulling and the pressure from the engine flows through, but I dont know if the stock CCV is real restrictive and wont let enough air through.

Any opinions are appreciated, Im really puzzled about the one way valve being able to let the vacuum pull, but if pressure was already coming in you would think it would work.

[DesktopDave]

You might want to consider a restrictor too.  I'm sure you're headed in the right direction.  Just figure out what it's supposed to do, and put either a one-way valve, oil trap, or restricted vac line to cure it.  I can snap some pics of the M42 in my e30 if you want to imitate that system.

[JoeDellio]

You might want to consider a restrictor too.  I'm sure you're headed in the right direction.  Just figure out what it's supposed to do, and put either a one-way valve, oil trap, or restricted vac line to cure it.  I can snap some pics of the M42 in my e30 if you want to imitate that system.

I checked it out at real.oem, but some real pics would be nice if you have them handy.

[JoeDellio]

I ran into a problem calcuating shit. In my FI cars I would always notice at idle a pull of vacuum of about 18 in. Hg, and down to 22 in. Hg on deacceleration.

Thing is, I looked up the CCV info and its only designed to pull 10-15 mbar, which isnt even 1 in. Hg! Are N/A cars under less vacuum for some reason? I dont understand the science of vacuum.

I was gonna use a regular old vacuum gauge to get a reading, but I dont even know if it will register in Hg inches. But I guess Ill have to give it a try just for kicks, and adjust it from there.

[JoeDellio]

Im just giving up on this engine. Its starting to nickel and dime me, plus Im tired of wasting time working on it and researching on the internet all hours of the night.

I found a complete engine w/105K for $650 that Im gonna pick up the first week of August. Due to the low compression in cylinder #1 (170psi and a 50psi difference from all others) it needs rings anyways, and at 250K its put in its work.

[DesktopDave]

I still haven't seen any solution for deleting the CCV.  I'd think that the engine swap is your best bet.  250k is a lot for an engine.

I'm still not sure what that CCV really does.  I'm guessing it looks like a diaphragm pressure regulator, vented to atmospheric pressure to keep slight negative pressure on the head.  If that regulator seal fails, it puts full vacuum to the head and starts pulling oil out.  I just saw a brand new 745Li with oil smoke at US customs!  I knew right away what it was...needs a CCV.  I'd imagine that this would cause no end of compression & oil starvation problems.

IMHO, a small pressure reducer with a filter would do the same thing.  With pressure being constant, volume (flow) is reduced by cross-section.  So a vac line with a small ID should do the trick...I'd guess like 1/8"?  Maybe add an aftermarket inline fuel filter to trap oil before that restriction, might be worth a try.