Sealing pcv valve system

Slix

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Joined
May 12, 2017
So, wondering about all the breathers on the engine.. one on the oil filler tube and one on the passenger valve cover behind the turbo...

When I put the engine back together, any problems with not using them and having the valve covers sealed and running the pcv valve system with a one way valve and catch cans for the oil?

Saw a good post about a performance pcv valve system with catch cans and the one way valve for under boost and just was wondering if I can eliminate the breathers and have the pcv system sealed?

Thanks any suggestions appreciated
 
One way or another the engine needs to breathe. Whether the breathers are on the valve covers or a catch can. You suggesting a completely sealed up engine other than the pcv?
 
Blow by must escape, so you’ll need a low restriction path for it to follow to get out of the crank case.
 
My only we question would be the quality of the air taken back into the engine. Wouldn't it be higher in temp and contain traces of oil?
 
My only we question would be the quality of the air taken back into the engine. Wouldn't it be higher in temp and contain traces of oil?

Yes. That temp increase would be marginal, and the oil needs to go somewere. If you don't burn it, you'll leak it. If you have excessive blowby and are ingesting excessive amounts of oil through the PCV system, your motor is due for an overhaul anyway.
 
I would rather vent it to the atmosphere than have go into the engine. Why would you want anything but cool clean air going into your engine at WOT? If you want your crankcase evacuated under full throttle a vacuum pump seems like the best way.
 
I would rather vent it to the atmosphere than have go into the engine. Why would you want anything but cool clean air going into your engine at WOT? If you want your crankcase evacuated under full throttle a vacuum pump seems like the best way.

Because it's really bad for the environment and it the vapor always ends up in the cabin and makes a stink. Recirculate it and burn it off.
 
I agree it is a good thing to have. I would never take mine off I just question its validity at WOT.
 
It has no validity at wot. The pcv eliminates itself in boost. It only works in vacuum.

Best you can do to prevent oil concumption is meter the flow through the pcv with some type of restrictor. Valve cover breathers need to be wide open and free flowing or the case will pressurize under boost.
 
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The PCV valve only opens under vacuum and closes under boost. The stock setup still burns the blowby gasses, via the hose connected to the turbo inlet bell.
 
It has no validity at wot. The pcv eliminates itself in boost. It only works in vacuum.

Best you can do to prevent oil concumption is meter the flow through the pcv with some type of restrictor. Valve cover breathers need to be wide open and free flowing or the case will pressurize under boost.

Wondering if you need both or just one side? Wanted to get rid of the breather behind the turbo. Don't mind the one on the oil filler
 
Wondering if you need both or just one side? Wanted to get rid of the breather behind the turbo. Don't mind the one on the oil filler
More breathers = better
I have 1 on each valve cover. Wish I had 2 on each valve cover.
 
The PCV valve only opens under vacuum and closes under boost. The stock setup still burns the blowby gasses, via the hose connected to the turbo inlet bell.
My motor has that inlet on the turbo bell capped...?
 
I have a k&n breather on the valve cover behind the turbo and the turbo breather inlet corked off. I believe this was a common mod on gns to eliminate oil getting sucked into the intercooler and making an oily mess in the intake.
 
Yes, probably one of the first things guys do.
 
I have a k&n breather on the valve cover behind the turbo and the turbo breather inlet corked off. I believe this was a common mod on gns to eliminate oil getting sucked into the intercooler and making an oily mess in the intake.

Except that now makes an oily mess down the front of the block.
 
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