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Discussion Starter #1
I currently have my stock oem honda pcv valve venting to atmospher, and I was just wondering if there are any other oem pcv valves that do not leak under boost? i.e oem supra, rx7 ...what aftermarket pcv valve could I use in replace of the stock oem
 

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you can easily implement a factory boosted vehicles PCV system into your car.

volvo's seem pretty easy to switch over, plus they are cheaper than porsch or vw systems to purcahse.
 

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if its venting to the atmosphere/catch can its going to expel pressure from the crank case under boost, if its hooked up to the intake manifold then as soon as your engine sees positive pressure, the PCV closes since its a one way valve. so wheres it leaking?? your question doesnt really make sense to me.
 

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Discussion Starter #5
if its venting to the atmosphere/catch can its going to expel pressure from the crank case under boost, if its hooked up to the intake manifold then as soon as your engine sees positive pressure, the PCV closes since its a one way valve. so wheres it leaking?? your question doesnt really make sense to me.
its not attached to the crank case, just hands off the intake manifold.
 

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Discussion Starter #7
Ugh. Disconnect it from the intake manifold. You're pressurizing your crankcase as soon as you hit boost. That check valve isn't designed to hold against so much pressure.
even if its disconnected from the valve cover?

its just venting to atmosphere from IM
 

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IM > Atmosphere = Pointless. Will cause boost leak, can allow unfilter air into engine, etc.
IM > Crankcase = Pressurize Crankcase under boost. Can/Will cause engine damage.

Valve Cover > Atmosphere = Allow crankcase to vent (good thing!).
Valve Cover > Vacuum = Potentially suck pressure out of crankcase/valve cover.
Valve Cover > IM/Charge Piping = Pressurize crankcase under boost. Can/will cause engine damage.

Block > IM/Charge Piping = Pressurize crankcase under boost.
Block > Atmostphere = Allow crankcase to vent (good!)
Block > Vacuum = Possibly pull pressure on crankcase. Can possibly increase power, oiling, etc.
 

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ok theres the tube that runs off the intake to the valve cover that lets air IN so the pcv can vent and then the tube that vents the crankcase "Possitively" into the intake. I assume OP is refering to the latter
 

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IM > Atmosphere = Pointless. Will cause boost leak, can allow unfilter air into engine, etc.
IM > Crankcase = Pressurize Crankcase under boost. Can/Will cause engine damage.

Valve Cover > Atmosphere = Allow crankcase to vent (good thing!).
Valve Cover > Vacuum = Potentially suck pressure out of crankcase/valve cover.
Valve Cover > IM/Charge Piping = Pressurize crankcase under boost. Can/will cause engine damage.

Block > IM/Charge Piping = Pressurize crankcase under boost.
Block > Atmostphere = Allow crankcase to vent (good!)
Block > Vacuum = Possibly pull pressure on crankcase. Can possibly increase power, oiling, etc.
x2
Im a little dislexic and the greater thans were screwin with me for a minute but after thinkin about this I agree completely
 

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Discussion Starter #14
if its venting to the atmosphere/catch can its going to expel pressure from the crank case under boost, if its hooked up to the intake manifold then as soon as your engine sees positive pressure, the PCV closes since its a one way valve. so wheres it leaking?? your question doesnt really make sense to me.

My black box vents to atmosphere.
My stock pcv valve is disconnected from the valve cover but is still attached to the nipple on the intake manifold. And i have read somewhere that honda pCV valves have a tendency to leak under boost..so I just wanted to replace the oem honda pcv valve with another oem one that will not leak under boost.

I am unable to find something that will cover the nipple of the intake manifold properly. any ideas of a fitting that will cover this whole properly and wont get sucked into the intake manifold?
 

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I don't quite understand your question also. But all you need to do is vent the valve cover to atmosphere. Plug the hole on the IM where the PCV use to connect to with a hose plug from the auto parts store. You can either take a smaller diameter hose and stuff it at the spot where the PCV use to sit or you can just remove the black hose where the PCV sits in and run a hose from the black box and vent that to atmosphere. It's as simple as that, been doing it for years.
 

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look at the late 80s turbo I4 mazdas PCVs. they are very similar in size, though not exact. probably wouldnt hurt to take a look at them together.
if that would work then look into a supra pcv, supposedly they're metal, and are obviously just fine in boost, and that's what the mazda I4 guys are upgrading to.

Can't say what year or model of pcv though
 

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I've been experimenting with this for awhile now, and just finished my pcv system.

An oem supra tt metal pcv will fit in the honda black box hole but the purolater one I tired leaked a little at 15 pounds and leaked a lot at 30 psi. I have "heard" that the oem toyota made valves do not leak at all.

What I ended up doing was going to mcmastercarr and ordering a heavy duty industrial strength check valve. It has a chemical-resistant fluoroelastomer seal(since I run ethanol and fuel may slightly contaminate the oil and it will just in general last longer then their buna-n-seal valves) will handle 1000 psi and 400 degrees. I ordered a 1/4 inch valve and screwed it directly into my performer x manifold. I run a line from that to the supra pcv valve. The check valve has a 0.03 psi cracking pressure so it closes the instant you hit boost. The check valve was like 10 dollar, and they have inline options as well. I also added a catch can inline with pcv valve to filter out any junk before it goes back into the motor. Using the check valve you could just use your oem honda pcv valve.I just re used the supra valve because it was what I had.


I still run my vented valve cover.In vacuum during cruise it draws in fresh filtered air from my catch can like a normal pcv system would using the oem intake arm,but under boost it vents like any other normal vented valve cover does..I have the best of both worlds
 
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