I know with the Advance Auto ones I've bought, the plunger simply didn't seat well. I could blow through it with my mouth. That's about 2psi. With an air compressor hooked up at 15psi, sometimes it would seal, sometimes it would leak fairly heavy. I bought (what i think is the GTX one) from Rosenthal and it would always seal and has yet to fail on me. I had one from advance fail to operate at all within a few hundred miles.

So for those of us who are less concerned with being eco friendly, whats the easiest/most simple setup? Currently I have a gutted pcv with a filter and capped the breather side. The car runs just fine. The only issue I have is I get some oil coming out from the pcv side with the filter which I plan to make a catch can for.
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like i've stated before: pcv and breather line into a catch can with a huge atmospheric port.

Attachment 212040

Sure thing! :

http://www.youtube.com/watch?v=mhbZBefwbtQ (not finished loading at the time of posting, but couldn't be bothered waiting anymore)

Sealed perfectly at ~2psi and held vacuum very well in the opposite direction, however flowed nicely with vacuum applied from the intake side :-p

Just as it should be, boost or no boost. Stop buying CHEAP JUNK PIECE OF SHIT RIP OFF COPY CHINESE MADE USELESS PCVs from your local retail outlet and stick genuine Mazda parts in there. For stuff that matters there is no substitute (cept possibly nissan or toyota parts instead)! Ditto radiator caps, ditto thermostats.

Article is 3/4 done, I'll post a link later or tomorrow when I'm happy with it and have moved it to a public location.

Fred.

Sorry man, but the pic is just way gay.
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Fred, stop being a condescending jerk.

Mazda OEM PCV valves for the miata are what most people buy. The OEM GTX valve is what everyone buys after the Miata-specific ones fail.

Exactly what was the failure mode, and where is the tell tale that it was the PCV failing? Link please ;-)

being black flagged on the track.....that was my tell tale sign.


now throw a handy vac on the IM side pulling about -10psi :)

The plunger side of the valve fails and the plastic housing itself comes apart... pics are not for the weak of heart:
https://www.miataturbo.net/forum/showthread.php?t=9920

I'm not sure I like the VTA in the catch can. Technically, it shouldn't hurt anything, but again, there's no reason to not collect that stuff. Compared to the 50/50 by volume gasoline you're spraying in, you won't make any real difference to how the motor runs. If you were burning much of it, the OEM wouldn't pass smog with a system like PCV in. :-)

Im pretty sure the green "breather" is far and away the BIGGEST restriction in the entire system, pluming the catch can to the turbo inlet is fine and not going to be the limiting factor.

Also, doing it as shown will want a filter on the VTA since you're going to suck some into your motor through there. Well, not likely, but in theory. The other way, everything's already a closed system.

Fred, you should go as PCV testing guy for halloween. I noticed sucking on my own PCV that with a little touch on the back of the punger, it would seal in the other direction. Call it 5 psi?

Good lord, did I not get the right PCV valve? I ordered the part number from the picture of the PCV valve showed earlier in this thread, and it came and was plastic. I just figured, well, the GTX one was plastic...

I've never seen one "GTX" look the same....and this is from mazda....ill have to look at mine again. I just know i have a factory valve, and it's fine.

LOL, nice work. Still, the part where it is bonded together is still intact. Plastic mouldings (like pistons) don't just snap in half by themselves and boost applied from the end axially simply would not have the required force to exceed the yield strength of the part in that fashion. I'd place a small wager that you or a mate leaned on it inadvertently at some point. Most plastic radiator tanks die that same way too. How many others have had this exact failure?

For y8s :

I rest my "buy OEM" case!

Brain, pissing oil into the intake doesn't say "failed PCV" to me, it could have been, but it could have been other things too. Which of the two possible ways was it heading into your engine?

Fred.

where'd you even quote that from? samnavy used his stock valve and it died.

^He's saying that particular kind of failure isn't possible and that I probably leaned on it at one time or another with my hand and cracked it... which I can't dispute. All I do know is that my stock OEM naturally aspirated Miata PCV valve broke and almost cost me an engine... and my Advance autoparts Mazda 323GTX Bosch part is still going strong. My case is not unique as a search will reveal.

FWIW, the Miata and 323 part numbers are different for all manufacturers... not just the OEM Mazda one.

Sometime this week I'll hit HomeDepot and get the parts for an M2cupcar designed catch-can and route it in the manner detailed above. I'll let everbody know how it works out.

I've been wanting to do this for a long time and this thread is just the impetus I need.

I wanna falcon punch someone....

Try page 2 ;-)

Sam, do you agree? It looks like it was cracked by sideways pressure. I myself have wiggled them sideways with great force to get them out on occasion, it could exactly that behaviour which broke it. Or perhaps the lean thing. What do you think?

When I prompted for that I was 50/50 expecting someone to post pics of the bonding coming loose and it literally falling in half. If that happens, to Mazda units, made in Japan, not NA, then I'll bite my tongue a little more. But, I strongly doubt it. The GTX isn't the only boosted car out of japan, they all have PCVs on them, all are SO similar in design and construction. And unless they are faulty or dirty they will all hold backwards pressure to some extent just fine.

Fred.

I haven't used a GTX valve yet. But I can say that every OE stock Miata valve I've tried (five) leaks over 10psi. Under that they are fine. I've had one autozone cheapy that wouldn't hold back more than a couple of psi. I had another noname for a supra that worked for about 500 miles and the started leak over 10psi.

Abe- that hose at the bottom is a drain, not VTA. The vent line is what runs to the intake. I'll update the image and label that.

I remember asking you this before, but tell me again how you tested them to prove that they leaked? Perhaps Miata ones just suck? If I can find some compressed air I'll try to test this Toyota one.

I've finished the article, feel free to rip it to shreds. Literally, be as hard and critical as you like. I'm devoid of feelings to hurt anyway ;-)

http://www.diyefi.org/forum/viewtopic.php?f=24&t=357

Hopefully it goes a long way to making sure I never type about this stuff again...

Fred.

M2: Oh, ah! Ok, then yes I like it! I sortof thought it was WAY too schematic to have a hose off the bottom. :-P

So why no baffles? You don't like the steel wool since you don't want to steel wool your engine internals? I could see that. I doubt a simple baffle will some anywhere NEAR working as well.

Probably one long coiled rope/wire would be good. In high reliability applications I've seen all sorts of things makes that way. But I don' think flat surfaces are going to catch much.

Same for me, I have the can and lacked a plan. Now, with both in hand, I'm sure the outcome will be grand.