115C - 125C for those not stuck in the dark ages :-p

We're not "stuck". We're just not quite ready to leave yet.

Anyway, feel free to tell us how cool you are when we bomb you with non-metric nukes.

hee hee heee.... Kudos Denis Leary, "we've got the bomb"

I think this one will work. The turbo rx7 guys have been using similar valves with the kynar/teflon construction successfully. Rated at 29"hg/150psi and 400f max momentary temps it should work.

I'm in. I got "outbid", but I wonder if we just told the guy we wanted a group buy on 20 or 30 of them if he'd be down. I'd get 3 or 4 myself. Anyone else in?

another one, different vendor BIN... will buy tonight

Ok, I contacted the guy with the first auction, he said for a group buy of 20 he'd knock them down 20% to $3.20 each, plus $3 shipping per address (don't know if the 20% applies to that as well). Which makes them very attractive if you want more than one.

I would want at LEAST two, but probably I'd get 5 or so, since they are useful for all sorts of things.

Anyone else want a few? Since they are cheaper than the crappy check valves from your local FLAPS, and 5 of them is cheaper than the fancy ones I see people buying, it might be worthwhile.

Let me know....

I bought one from that last auction. If you want to wait, I can report back once I have it installed and tested.

Sure, sounds good. 'Course, you beat me out at $4.50. Maybe in the mean time I'll come up with plans for where to spend the $1.30 I'm going to save. Maybe I'll buy a whopper!

Anyway, just fishing for interest here. My latest catch-can fantasy involves two valves...

Abe, If you are getting them can you order me two or three? I can split shipping costs with you if you are interested.

I am having issues with my PCV

Woo-hoo, we're a third of the way there! Anyone else in?

I'll buy some. Oil in boost piping = bad.

Get yours yet Rob?

not yet
 

no- guy said he ran out of stock and it would be here in another week. He hoped that wouldn't jeopardize future business with him. :nono:

Jump ship! Get mine!

$12.30 for 3 shipped... I got
Me: 4
Adam: 2-3
Quad: 3

Halfway there... And yes, I'm quite tired of my intercooler running like a fine oiled machine

Ok Abe. Got my refund. I'm in for 3... it's like buy two get one for free! :D
When/how are you collecting funds?

I'll get 3

...Waiting to hear back from the guy if he wants to pay seperate or what.... Will let you know.

If anyone else wants in, that would be awesome - otherwise I'll have to buy like 10 myself. :-\

If you don't mind sitting on them I'll probably take a few in about a year. No promises though, but...

Fred.

btw
 

My can has no "stuffing". Just relies on the right angles to send the vapor down and let it condense the walls. Well. I popped the hood to screw with my tps and got a good view of vapor coming through my filter. It looked like a little chimney - so stick something in the can if/when you build it.

Abe should we give up on the group buy?

I pinged the guy one more time. If he doesn't get back to me in a day or so, yeah, just forget it.

Sorry if it doesn't go through (though I still hope it will!), the guy seemed into the idea originally.
-Abe.

P.S. Fred, you can have them in a year, but you'll have to come pick them up.

Yeah what's happening?

abe shops at shirt.woot.

Clever, but no. I have friends who do.

Ok, so... Thinking about the catch can thing, I've never really come up with something I like.

I assume, idealy,
1) the valve cover always has flow through it.
2) the best place for those fumes is the intake manifold
3) a catch can is needed between valve cover and "vent to atmosphere"

And two things I'd like to see, but am not so sure on:
4) A catch can on BOTH manifold vents is best
5) venting to the air cleaner is better than to the atmosphere

Anyway, here's a couple things I was looking for:

http://abefm.smugmug.com/photos/335866155_sXAkz-XL.png

From 4) above I think two cans is what I want. And the problem with Method #1 is that it doesn't follow 1) above.

Anyway... I'm curious about people's thoughts.

Explain to me why you would need a check valve venting to atmosphere?

I'd personally want both the check valve & the pcv valve.....to the IM, the end.

Abe, based upon your ideas/contributions, I made this beauty (I think it's like your first example):http://i258.photobucket.com/albums/h...narot/vent.jpg

If manifold vacuum is present, then we'd see crankcase gas evacuation. Win.

In boost, the manifold would be safely sealed AND crankcase gasses would have the ability to VTA. Win and Win.

However, one problem I see right away (in boost) is that the crankcase gases must overcome the resistance in check valve #2, which, depending on check valve design, would possibly result in "high" pressure in the crankcase.

If no checkvalve before VTA, then in vacuum conditions, fresh air would be drawn INTO catchcan and into mani.

i fail to see the need for two check valves....

youll still want the pcv.... or straight up fuck anythign running to the IM.

try this. gut your PCV and try to idle the car, shit will run like asshole with the big as vacuum leak you've created.

so a pcv like normal will prevent that, and allow the fumes to be burnt off like a good boy. the check valve will prevent any boost from entering the catch can or crankcase....meanwhile to crankcase will be open to atmosphere through two ports....

+1
Your backwards check valve arrows crossed out weird me out. :-) But your pictures are very clean!

Anyway, to the actual point, yes, you'll have a vacuum leak if you just let the mani see the atmosphere through the catch can and the crankcase. Is it enough to be a problem? I dunno. But that's why I have the checkvalve, so that under vacuum there's no leak.

I'm just hoping the check valve to atmosphere doens't have a lot of resistance... And I'm hoping that not flowing air through the valve cover is ok.

I think the issue with no cross flow is you're not really flushing out all the moisture you could be, which translates to oil that doesn't last as long. So far all my best ideas involve way too many catch cans. :-) I guess under boost you can live without cross flow.

I really think running to your intake tube is a better idea than venting to atmosphere. Chucker's drawing looks reasonable beyond that.

then why bother with a line to the IM at all? vacuum will always keep it shut...thus never venting... kinda defeating the purpose..since it's during low vacuum the pcv opens and draws air in from the crankcase.. if no line is present to the IM, no boost can go into the crankcase, and no need to bother with any check valves.

Um, are you claiming there's some difference between a "PCV" and a check valve?

The idea is so the manifold can suck on the catch can (and therefor the valve cover) but not suck from atmosphere (which I'm undecided if it's a good idea), nor can boost pressure blow into the crank case. Hence the two check valves.

i am claiming there's some difference...

http://boostedmiata.com/technical/pcv-operation.gif


during both high vacuum AND boost it's closed.

Ok, that is interesting! I didn't know that!!

I'll revisit my drawings a bit, but I think that's going to be a big help! Something along the lines of switching the two valves in your drawing seems to do it for me... Soon, very soon...

hmm. i'm following this thread a bit more closely now. went out for a spirited run with a lot of high end cars on saturday, and it involved a lot of running at high rpm and a couple extra pounds of boost. by the end of a couple hours drive, i was producing a good amount of oil smoke from my tailpipe (at least half a dozen people made sure to mention the car was smoking pretty good...).

when i finally popped the hood after getting home, there was oil everywhere that it could possibly get to from the breather on the driver's side of the motor. popped the hose off the PCV and there was oil all in and around that as well...

question is, think running a double vented catch can like the original post, and plugging the IM port solve my issue for now (assuming i haven't done the rings in?) while i wait for a couple of those fancy check valves to come in the mail?

I doubt you harmed the rings, at least, not from the oil directly, but I guess potentially from detonation if the oil coated the intercooler and/or diluted your octane rating significantly.

i doubt it too, but i generally am just a huge vagina and assume i am blowing my shit up every second i'm driving the car :-)

Do wash out your intercooler with solvent before thrashing it hard again though won't you?

yeah, i have been meaning to disassemble the piping and clock my compressor and some other small projects. so maybe this is the fire under my ass i needed.

Agreed- remove the pcv from the cam cover and vent that port/line to the catch can along with the original cam cover vent. Was it smoking only under boost? Is it smoking now out of boost? Those are some good indicators of damage. But IMO not addressing the crank case pressure is a good route to premature wear that could be a voided. Blow by is there whether you see it or not.

i believe i saw the most smoke when i was making a higher load boosted pull, say 5th, and then let off. the smoke really poured when i let off.

pulled apart my piping yesterday after work and didn't see ANY oil in the cold side of the charge pipes, and only a scant bit on the warm side. reached up into the intake mani and there was some crud in there but not like a pool of oil.

we'll see what my compression and leakdown numbers look like, once i get the catch can on and boost pipes rerouted (figured i'd take the opportunity to clock the compressor down, while i was in there :-) )

I need a check valve
 

Now that I've learned that a PCV valve is more than just a check valve (thanks brain), I've decided to run:

1) a GTX PCV
2) a check valve between mani and PCV
3) and rout the vent line just before turbo inlet, maybe with a catchcan.

So which check valve?

This one is inexpensive and compact but it's only good to 275F and it's homo plastic.

This (search p/n 7775K51) is more expensive (2x the price + freight) but it's brass, it's piston type and it has a viton seat good for 400F. It should outlive the car.

Also, I was thinking of assembling a check valve out of brass pieces like a homemade MBC with a light spring and a steel ball. Should be easy enough but the cracking pressure (vacuum) might be too high and the flow might be too low, plus the thought of the engine possibly digesting a hard steel ball and spring doesn't sound too bitchin'.

Any others you guys can recommend? Experiences?

Thanks

Run the catch can just to keep the oil out of your entire intake. I got oil in my intercooler and lemme tell ya, it sucked cleaning it out.

The kynar/viton is what the turbo rx7 guys have been using and what I was going to try out. But I agree- the brass valve definitely looks superior.

I used the first one to solve my smoking problem (off-boost). Its a very high-quality PVDF material which has a melting point of over 340 F so no worries there. I don't have a catch can BTW and my hotside valve cover vent is plumbed pre-compressor.

At first I used no PCV. but then found out that unlike the PCV, this valve opens even at very high vacuums, thus causing a high idle. Then I put the PCV back, it looks like this now:

http://img125.imageshack.us/img125/8712/dsc00513yi3.jpg

Been running for about 500 miles so far and its holding up fine.

Pipe,

Yeah, that's the exact setup I envisioned. The apparent compactness of the plastic unit makes it look perfectly suited; any longer/larger and there may be a fitment issue...

Every time I turn around there's another $100 in bullshit I have to buy to get this fucking car running.


Why not run a pcv for each side of the valve cover, then the check valve, straight to the intake plenum? This would eliminate the catch can.

its not absolutely required, that's what I gathered from this thread. I doubt you'll have issues when both vents are plumbed right. The way I plumbed mine, the crankcase can vent via the pre-compressor vacuum when in boost; the one-way + PCV side will prevent positive pressure. Off-boost, the whole thing works like the factory intended it to.

what's up with putting a check valve in the line to the charcoal canister? Necessary?

considering how hard I'm going to drive this car at 250whp, its required. With my luck, it will blow the dipstick out immediately and fill the piping with oil. It happened several times on my vr6.

I'm glad someone listens to me....well if not listens, is at least as smart (stupid?) as me :)

In an effort to remain emissions compliant while still removing oil from the incoming air I think I'm going to do this, it's essentially the same thing as Brain's idea except instead of VTA there's a line with another checkvalve going to the intake. Aside from the emissions thing might there not be benefit from routing pre-compressor versus VTA? When the line to the manifold is closed in boost only the line to the compressor inlet is available and it is servicing both the breather port and the pcv port, allowing twice the evacuation potential over the stock setup. Plus in boost shouldn't we be seeing low pressure in front of the compressor further aiding scavenging of the higher pressure in the crankcase? edit: thinking about using these check valves http://cgi.ebay.com/Check-Valve-HHO-...1.c0.m14.l1318
http://i19.photobucket.com/albums/b1...catchcan-1.jpg

I've blown an FE3 dip stick out without boost!! It's required for hard driving period and not required if you are a red light racer/pretty boy/nancy. Enlarging the ally holes as Rob has done on his FE3 is required for the FE3. Even without boost.

doe- you need two cans to be OE emissions compliant just to keep the Pcv and vent systems separated. IF the pcv shares a can with the vent line, then it can vent to air via the can-to-intake line under pressure (blow by). And when in vacuum the manifold is going to pull air through the cam cover vent line - which will inevitably be easier than pulling through the pcv valve. You could put another pcv valve in the cam-to-can line, but IMO you want a free flowing line available to vent blow by under boost and the valve will just impede venting.

I think Fred is right. Even a normally aspirated car that's driven hard is going to benefit from a catch can. The inside of my showroom stock Miata's manifold was absolutely covered with blow by residue after a few weekends of racing because we could not modify any of that system. That's what running to redline for 45 minutes at time gets you. Add boost to the environment and it's only compounded.

why is there only 1 pcv? Why not have pcv to both sides of the valve cover, or 1 pcv in the line to the intake plenum with a check valve?

yeah, I see what you're saying now. I'll keep the same placement of check valves but keep the pcv and breather independent.

I understand the value of a catchcan on the vent side to prevent oil in the intercooler, presumably reducing its ability to exchange heat...

But oil residue in the intake mani... Is it really a problem? Is it actually enough oil to increase the possibility of carbon deposits or buggered injectors?

i thought the issue was that it fucked with the AFR

Adding oil reduces the effective octane of the fuel. More oil, more chance of knock.