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PCV Removal

  • Thread starter Thread starter Venom351R
  • Start date Start date Mar 17, 2008

Venom351R

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Apr 27, 2002
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Mar 17, 2008
#1
  • Mar 17, 2008
  • #1
I want to run some aftermarket valve covers but the issue of running breathers and taking out the PVC Valve becomes an issue. I was told on another site that removing the PVC valve and capping off the tube on the Cold air and running open breathers will be ok. There was a big write up about the PVC but the poster was confusing on if it was ok to delete the PVC or not. I just dont want to take off a factory item w/ out knowing it will be fine w/ the different set up. So is it fine to delete it and run open breathers or should I run closed breathers on my new valve covers and keep the line that goes from the valve cover to the cold air?
 

BlownFiveLiter

have car, will race....wait, it doesn't run
15 Year Member
Nov 29, 1999
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Mar 17, 2008
#2
  • Mar 17, 2008
  • #2
PVC... pipe?

If you decide to eliminate the PCV, you need isolate the crankcase from any metered air source. You'll want to cap off the tube from the oil fill and the vacuum line that runs to the PCV from the upper plenum. The tube from the oil fill supplies a fresh source of metered air through the crankcase, and expels it through the PCV into the plenum to remove any vapors without releasing them into the atmosphere, so you should be ok removing it with no adverse affects on how the car performs.
 

Venom351R

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Mar 17, 2008
#3
  • Mar 17, 2008
  • #3
ok cool so as long as everything is capped off the PVC into the intake and the tube that runs to the valve cover/cold air then I can run the open breathers w/ no problem.
 

BlownFiveLiter

have car, will race....wait, it doesn't run
15 Year Member
Nov 29, 1999
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108
Chicagoland
Mar 17, 2008
#4
  • Mar 17, 2008
  • #4
Correct. It's one of those all or nothing kinda deals, or you open yourself up to unmetered air getting in and screwing with AF ratios.
 

Venom351R

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#5
  • Mar 17, 2008
  • #5
Awesome thanks for the help, just wanted to be sure that it was fine to do this before I went ahead and bought the valve covers and breathers.

Here's what I'll be getting.

http://store.summitracing.com/partd...1&part=FMS-M-6582-L302&N=700+115&autoview=sku
 

HISSIN50

"How long does it take to get help in here?
15 Year Member
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Mar 17, 2008
#6
  • Mar 17, 2008
  • #6
The only mild caveat is that the PCV set-up is better. It actively scavenges crankcase vapors (via manifold vacuum) whereas breathers are passive (when enough pressure builds, it gets pushed out. There's no active scavenging).

Would I let this slow me down from swapping to straight breathers? Nah. I just wanted to say something since it is one downfall (along with a possibly oily mess under the hood or where ever you dump the breather hoses).
Good luck.
 

Venom351R

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Apr 27, 2002
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Mar 17, 2008
#7
  • Mar 17, 2008
  • #7
HISSIN50 said:
The only mild caveat is that the PCV set-up is better. It actively scavenges crankcase vapors (via manifold vacuum) whereas breathers are passive (when enough pressure builds, it gets pushed out. There's no active scavenging).

Would I let this slow me down from swapping to straight breathers? Nah. I just wanted to say something since it is one downfall (along with a possibly oily mess under the hood or where ever you dump the breather hoses).
Good luck.
Click to expand...

What if I used two closed breathers w/ the valve covers and just kept the PVC set up the way it is? They make the closed breathers w/ the nipple on the end to hook the small hose to that goes from the VC to the Cold air.
 

Methodical

15 Year Member
Dec 1, 2003
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Mar 17, 2008
#8
  • Mar 17, 2008
  • #8
Redline_351R said:
What if I used two closed breathers w/ the valve covers and just kept the PVC set up the way it is? They make the closed breathers w/ the nipple on the end to hook the small hose to that goes from the VC to the Cold air.
Click to expand...

That sounds better to me and plus it keeps the stock system in place.

Are you running stud mounted RRs? I want to run those VCs (the Cobra one's actually) just can't get any dimensions on the VCs so that I can make sure they clear my RRs and EGR valve.

So I'm subscribing.

Oh can you post a link to the PCV writeup?

Thanks
 

Venom351R

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Mar 18, 2008
#9
  • Mar 18, 2008
  • #9
Methodical said:
That sounds better to me and plus it keeps the stock system in place.

Are you running stud mounted RRs? I want to run those VCs (the Cobra one's actually) just can't get any dimensions on the VCs so that I can make sure they clear my RRs and EGR valve.

So I'm subscribing.

Oh can you post a link to the PCV writeup?

Thanks
Click to expand...

Yes I am running stud mout RR's they are 1.7's,

Here is the thread I read regarding the PVC removal or keeping it.

http://www.sn95forums.com/forum/index.php?topic=9567.0
 

Methodical

15 Year Member
Dec 1, 2003
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Clinton, MD
Mar 18, 2008
#10
  • Mar 18, 2008
  • #10
Redline_351R said:
Yes I am running stud mout RR's they are 1.7's,

Here is the thread I read regarding the PVC removal or keeping it.

http://www.sn95forums.com/forum/index.php?topic=9567.0
Click to expand...


Thanks for the info. When you get them can you post the inside dimensions of the VCs?
 

Venom351R

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Mar 19, 2008
#11
  • Mar 19, 2008
  • #11
Methodical said:
Thanks for the info. When you get them can you post the inside dimensions of the VCs?
Click to expand...

Yeah I can do that I'll let you know. Not sure when I'll be getting them exactly but will be sometime around early-mid may if not before.
 
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