Those revisions are based on what I see coming out of the can filter now and how Mazda built the internal cam cover oil trap. But yeah- I don't dig the idea of that stuff in the can IF it's got a line back to the intake or oil pan. I'm sure the internal divider could be improved upon - similar to the cam cover - just more surfaces and blockages. If you've ever looked at the cam cover oil traps you'd have second thoughts about thinking flat surfaces don't trap oil.

 

What about plastic sos pads? Like this- http://www.y8s.com/celica_gone/air-oil/
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my mouth, an air compressor, the audible lack of rattle, my dipstick tube unsealed, the oil saturated engine bay, etc.


you gotta remember, your rings don't seal 100%, the loss has to go somewhere....

i don't even know what we are arguing. you got like 38 people here saying they had failed PCVs. they fail. crankcase pressure is bad. small breather port isnt enough. catch cans catch oil. yadda yadda yadda.

 

I'm asking whether you think, or better, know, whether it was going through your turbo and intercooler to get to your manifold, or directly into the manifold through the pcv?

If not through the pcv, it was doing it's job. If you are telling me you think that boost was causing your oil filled turbo by leaking through the pcv then I am telling you that I don't believe it one bit. Instead I'll tell you that I think it was simply blow by causing it and the pcv remaining shut as it should. EDIT obviously the boost leaking in could CONTRIBUTE to the issue, but it couldn't cause it alone.

Even if you gutted the pcv and allowed it to flow free boost into the engine I say that the breather is at fault for not out flowing the pcv orifice which is maybe 4mm ID. If your breather is in good shape, boost leaking in there wouldn't affect it.

I've rambled again, but hopefully you are more clear one what I'm getting at.

btw, 500,000 people could say bush is a great president and I wouldn't believe them. What makes you think 38 miata owners saying "my pcv valve caused this!" will have me believing them? There is more than one possible explanation for the smokey exhaust oily intake syndrome. Don't be so quick to blame a tiny valve that could be present or not present and still not matter two *****.

Rob, I just tested the toyota valve to around 12psi pressure differential, and although I can't tell you it sealed perfectly (there was some VERY slow leakage) it certainly wasn't enough to warrant concern, or say increase the idle (had the valve in backwards to generate the pressure difference). Without the valve in place the idle went sky high (as expected DUH!) but the "leak" was not significant enough to even register as a change in RPM, now, adjust that situation to full noise 7000 rpm full boost operation and the % of airflow attributed to the valve is SO small it just does not matter. In the case of the crank case pressurising, INCREASE the flow out of it. Oh, wait, you did that and it solved all your issues ;-)

When you guys say "my pcv leaks above X psi" are we talking "barely at all, but something i can just hear/feel" or are we talking "it nearly blew me out of the garage". Facts remain, the hole in pcv valve housing is NOT big enough to flow any significant air in either direction for either idle purposes or boost wasting purposes or crankcase pressurising purposes (unless the escape route is WAY TOO SMALL).

Can anyone post pics of the miata BP or B6 cam cover and the actual size of the OEM breather hole? $5 bucks monopoly money says its smaller than a 12 year old boy at the urinal on a cold day!

Fred.

 

probably.... ROFL





either the case, I don't want a pcv that I can blow through, even if it's the most insignificant amount...if I can blow through it, it's gotta be worse when 12 more pound of pressure blow through.

what that said, I've had zero oil loss through the breather line on this healthy Frankenstein motor with a simple factory valve in place.

the only thing I argue, is the advance auto ones suck. and that we should all tap our breather ports out 1/2"

 

You and your post'n'edit .... I've already written an entire reply before you get your edit in.... for a mod, that's pretty slack :-p A second post would be better when the thread is active like this.

Agree 100% with all you said. The toy one I could not blow through at all, but under 12psi of suck it drew slightly, I couldn't hear it, but if I put my finger over it the vacuum slowly slowly SLOWLY built up. I'd deem that acceptable for any reasonable boost level.

What I wrote before your edit :

So you are still going to blame it purely on the valve rather than a distinct and obvious lack of flow OUT of the crank case when the valve is closed? For that much oil to get in there there was another issue too. Did that oil come out through the breather? (Is that the fourth time I've asked that??) If not, was it the turbo seals? If it was the breather, how do you suppose just having pressurised air caused oil to magically come out? Sounds like a lot of oil dwelling in the head at the same time to me. The early 4AGE engines did this. When revved hard continuously they flooded up top and PCV good or PCV bad (NA, not boosted) they would flood oil into the intake and create a smoke screen too.

Fred.

 

watch at about :19 in and you see what full rpm under boost looks like. and yes, the port is small like 5/16 or so.

 

I agree, I don't see any argument. I don't see any need for more check valves, either.

All I've learned from this thread is to add a catch can between valve cover and turbo inlet. I'm not disappointed in this, rather now I feel well educated.

Oh, and that. :-) I will be doing that for sure.



re: Video - yeah, that's a pretty insignificant amount of vapor compared to 300 CFM or more your engine is processing. So might as well plumb it back in and hug a tree. :-) Plus, without that filter to clog with oil, it'll actually flow better too, lowering crankcase pressure.

 

What check valve were you guys getting? ebay is too old....

 

Huh, where you wanting to put a check valve?
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Search for "viton check valve". I actually never installed mine. At the moment, I'm running that modified Kia cam cover with the two 1/2" npt ports I installed. I reinstalled the piece of the internal baffle I cut out so now there's just a division midway. That cut the amount of oil I was getting in my catch can by about 90% or less, and have no signs of crankcase pressure. Are you running a can?

 

No, but I might soon on the pcv line. The line is heavily soiled in oil, the baffles seem to be useless. Breather side is clean as a whistle.

 

Mine looked the same until I went with these big vents. Now the PCV line is clean and function as OE and the vent lines are doing their job and catching the blow by. I'm guessing that the OE vent system on the B engines is insufficient for boost. Part of that is due to the baffle plates. The PCV side baffle has a nice opening to allow easy venting and the vent side does not. As mentioned, OE turbo'd cars all address the added cc pressure by increasing the vent systems capacity (substantially) over the normally aspirated cars. IMO, if you're boosting a car that is normally aspirated OE, then the cc vent system must be upgraded in the process.

 

blah. Every now and again when i get out of boost and idle I smell some oil be burned. I want the check valve to completely stop any boost from leaking into the crankcase.

I think i really need to go with a catch can however, what I think is happening is the high vacuum that i produce when i decel in gear is causing oil to be sucked into the IM then burned. It never happens during normal driving, and never while in boost, only after.

 

I think i'm having this exact same issue. I have the GTX PCV in the stock location, a breather filter on the other side.

If I pull the hose off the IM, its got oil in it. I'm pretty sure my car is drinking oil. Its been doing this since I built this motor and I dont know why.

The other day I was checking over my car before an autox and I noticed that my oil pan gasket RTV looked like it was being pushed out from the inside, as if there was so much pressure in the crank case that it was trying to escape past the oil pan.

I'm guessing I need a check valve AND a catch can between the VC and the IM.

 

im blaming my turbo. run a catch can for two weeks without a drop. still a random blue puff on decel. so its either the turbo or valve seals.

took my turbo apart the night before the dyno and my turbine is not true anymore and it had tons of shaftplay. when i did my pulls it started smoking when i got into boost above 8psi or so.

 

I'm pretty sure this isn't related to my turbo leaking oil. It happened when this motor was N/A as well. It is hardly leaking any oil (very small seep from cam seal) yet i'm losing oil as if its not 7 dollars a quart (mobil 1)

My best guess is that its getting past the baffle in the VC and straight into my IM and burning up. I was looking at the original catch can in this thread and thinking I would do that with a line plumbed back to the IM with a PCV.

 

This thread = win

I my catch can route was pressurizing the crankcase

Basically waht i took from this thread is that:

Ditch the OEM PCV get the 323 gtx one
PCV connects to the intake manifold with check valve
Breather goes to the catch can and catch can goes pre turbo

Im still absorbing the 10 pages that i just read so please correct me if im wrong


EDIT: This should be in Useful saved posts. Or maybe a shorter version in there but it definetly should be there IMO

 

You don't need the 323 gtx pcv valve if you're installing a check valve inline.

Next I will be installing a check valve between the catch can and the valve cover breather port in the direction so it doesn't let air go towards the valve cover. This way when the PCV valve is sucking in partial throttle the pressure in the crankcase will go down since the vent side of the valve cover will be plugged by the check valve not letting any outside air in.

 

I agree. I might try to make a catch can from the VC to IM after PCV though using an air compressor filter and some 90s. Not sure if I can get it to work but it might be worth a try. Hell I just spent the last 30min reading 10 pages so I kinda feel I have to make a contribution