show me- I was using what I thought was a first gen supra turbo pcv valve (non OE). Had a metal valve core, but after 1k miles was already leaking.
|
I'm refering to a turbo bypass valve. We make a replacement, the OEM piece should look like this but in plastic:
http://www.forgemotorsport.com/conte...duct=FMDVMSP02 Manifold pressure will open or close the valve when its needed. Under boost it will be shut, open under vacuum. You can get them online or at junkyards for a song. That and a few reducers should do the trick... I plan on trying one of our fancy alloy jobbers once I get the turbo in my car... |
Originally Posted by m2cupcar
(Post 263286)
no, the problem was there were rockers in an mx6 ;)
I think the real problem was that the vent hole is about 1/8" - hard to blow through, so I'm sure it's equally difficult to vent blow-by thru Fred. |
Originally Posted by PAT!
(Post 263383)
I'm refering to a turbo bypass valve.
|
wouldn't the simplest solution be a one way check valve inline with the pcv. that way the pcv can still work as intended, and the check valve would be extra insurance that the crankcase will never get boost.
|
Originally Posted by Braineack
(Post 263440)
wouldn't the simplest solution be a one way check valve inline with the pcv. that way the pcv can still work as intended, and the check valve would be extra insurance that the crankcase will never get boost.
|
I couldn't find a good check valve, but I did put two in there, hoping the pressure drop across the first would be enough to leave one left. Probably crap, but it's what I did.
Originally Posted by m2cupcar
(Post 263042)
I've yet to see it, but word is under very harsh conditions (track events) the captured oil gets heavily contaminated with water, creating an oily froth. So that might be a reason not to dump it back in.
I think you can dump it back in by hand if it's clean. After the water comes out.
Originally Posted by rb26dett
(Post 263198)
Dip stick was 4 inches too high after a lap. The hose from the end of rocker went straight down and out the bottom with no bottle/restriction at all. NO turbo. ie its marginal in stock form when thrashed hard. Of course that must have been caused by magic boost dust leaking past the pcv valve right...
Originally Posted by PAT!
(Post 263383)
I'm refering to a turbo bypass valve. We make a replacement, the OEM piece should look like this but in plastic:
http://www.forgemotorsport.com/conte...duct=FMDVMSP02 Manifold pressure will open or close the valve when its needed. Under boost it will be shut, open under vacuum. You can get them online or at junkyards for a song. That and a few reducers should do the trick... I plan on trying one of our fancy alloy jobbers once I get the turbo in my car... Anyway, having a suction would help - with a decent catch can, you could plumb it back into the intake, ahead of the turbo, and that can't hurt. But perhaps a bigger bung would help. There's not as much use to sucking off when not on boost..... And on boost, all these check-valves are closed. If it switched to atmospheric would work.... |
Originally Posted by AbeFM
(Post 263469)
I couldn't find a good check valve, but I did put two in there, hoping the pressure drop across the first would be enough to leave one left. Probably crap, but it's what I did.
Isn't boost-dust something you can pour in the tank? I'm kinda wondering about the lack of suction.... There's not as much use to sucking off when not on boost... Fred. |
I used to get them free from Supra owners after they installed an upgraded valve. Maybe 5-10 from a junkyard.
The valve should pretty much exactly mimic the operation of a check-valve but without the leaking and blowing open. I'm proposing installing it off of the valve cover, flow should be restricted by the size of that orifice. Sorry I didn't quote, I'm feeling lazy... |
If it were a steady state flow it would mimic it exactly, but being a pulsed flow it will not. It will puff out and then back in again. With the check valve it works like a small pump removing gas with each pulse.
Think about a piece of elastic with a ratchet on it. |
So... Why not hook it in backwards.
You have a check valve to the intake manifold, so when in vacuum, you get suction into the motor. When on boost, there's no flow (unless your crankcase pressure is higher than boost pressure). No catch can here Also, have a boost actuated valve, when the engine boosts, it would open, the rest of the time it's closed. This would have a catch can, and vent to atmosphere (or maybe between air filter and turbo). The giant opening wouldn't matter since it would only be open on boost, and doesn't go to the manifold so it won't effect idle. So there's no vacuum leak to worry about, you're covered under boost and vacuum, you're not leaking all over the place, and your crankcase is well vented. |
The big thing with the FE3 at least is just totally insufficient area to exit when the pcv is shut at WOT or on boost. The hole is just too small. Enlarging it and adding a second is a good way to go IMO.
|
I have a similar setup, but I used an electronics jiffy box w/rubber seal, stuffed it full of stainless steel wool, and put a screen in so no strands would get sucked into the motor. It seems to be trapping a very small amount of oil post PCV...
|
I just got a box, a nice one, and I'm stoked!
I want to get a much bigger outlet. Then I guess I'll go from that, to the can, to a T which goes to a vent or the intake manifold, with appropriate check valves. And I should stuff the box with steel wool and screens. |
m2cupcar, where abouts GA are you?
|
alright, so I have the stock pcv valve in, and a little filter on the driver side of the valve cover. am I using barrowed time with this setup, much like my 6" diff? I know the filter is supposed to give a sketchy idle once in a while, but I only idle when there's a spec miata infront of me on the track ;)
mostly I road race my car, although it still sees a couple thousand (2 or 3k) street miles a year. whats the best option for this pcv issue? 323 valve? catch can? from how much everyone seems to know about the situation, I think I missed a previous thread... |
more testing
Near Emory U.
Went out and made a couple of ~15psi runs (sans pcv valve) from low rpm to rev limit using the OE vent and the pcv vent to the catch can. Still got oil seepage from the cam cover gasket. The passage at both ports in the Mazda cam cover is not quite 3/16" (~9mm). So I swapped in my modded Kia valve cover (post documenting cam cover mods here - and here - original thread). Went back out and made the same runs and had zero visible oil seepage and there was no noticeable increase in the can oil level. Yes, the cam cover gaskets weren't the same- but the Kia gasket is about 3 years old and the other a year. Both feel similar. At ~9psi (waste gate actuator base) there's no problems - but the higher boost changes all that. |
Great test rob, and exactly as I thought it would be. Now, leave the kia top on, put the ordinary pcv back in and call it a day :-p
Fred. |
I need to buy a proper mazda turbo pcv. I had a third party supra unit on and it couldn't take over the base WG boost. Same with all the other OE units I have laying around... Though I haven't tried them with the new cam cover... maybe that was your point.
|
No, I was just giving you shit :-)
Fresh OEM FTW :-) I look forward to you having it all working properly. HMMMMMMMMMMMM, I wonder if my leaking rear main seal is because of this?? Perhaps I didn't stuff up the install, perhaps my 17psi pushed it out!?? Fred. |
All times are GMT -4. The time now is 07:22 PM. |
© 2024 MH Sub I, LLC dba Internet Brands