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Valve cover breather?

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Old Oct 7, 2004 | 04:20 PM
  #21  
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When installing a breather, is everyone here removing the PCV system?
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Old Oct 7, 2004 | 06:22 PM
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Ha, another 2yo thread brought back to life...

It is not good to dissconnect your PCV system. You may actually worsen your oil consumption only now through the piston rings while also increasing blow-by oil contamination.
The vacuum in your intake manifold pulls a slight vacuum in your crank-case to help seat your rings. Ever heard of a vacuum pump? These are usually used to promote a good engine vacuum after the installation of huge cams and forced induction systems. They're also used to allow an engine builder to use lower-tension piston rings to help reduce friction (more power), while still seating the rings. W/O engine vacuum, your rings may not seat properly and you could be looking @ more oil consumption, and maybe even some leaky oil seals (ie:valve cover gaskets/front cover/ect.).
The recommendation to assist in your problem is a catch-can and perhaps the swap to an LS-6 PCV system. You may still lose oil, but it will collect in the catch-can, instead of the intake system. With this, you'll still keep the needed PCV system to keep those rings seated.
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Old Oct 8, 2004 | 04:07 PM
  #23  
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Originally Posted by NoseUpChromeDown
Ha, another 2yo thread brought back to life...

It is not good to dissconnect your PCV system. You may actually worsen your oil consumption only now through the piston rings while also increasing blow-by oil contamination.
The vacuum in your intake manifold pulls a slight vacuum in your crank-case to help seat your rings. Ever heard of a vacuum pump? These are usually used to promote a good engine vacuum after the installation of huge cams and forced induction systems. They're also used to allow an engine builder to use lower-tension piston rings to help reduce friction (more power), while still seating the rings. W/O engine vacuum, your rings may not seat properly and you could be looking @ more oil consumption, and maybe even some leaky oil seals (ie:valve cover gaskets/front cover/ect.).
The recommendation to assist in your problem is a catch-can and perhaps the swap to an LS-6 PCV system. You may still lose oil, but it will collect in the catch-can, instead of the intake system. With this, you'll still keep the needed PCV system to keep those rings seated.
Good info, but I already got the LS6 pcv with a catch can attachted. Just got oil leaking from the bottom 2 corners of the timing cover. I changed the gasket and put some gasket maker across the bottom of the cover llike a month ago but still slowly leaks. Just wondering if a breather cap would help this or if I shouldn't worry about it.
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Old Oct 8, 2004 | 08:23 PM
  #24  
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A breather probably wouldn't help. If you think about it, with the PCV system connected to the intake, the system has a bit of a negative pressure, or vacuum which would do far more for a leak than just venting the system into the atmosphere.
Sounds like you have something wierd going on there. Have you replaced your actual PCV valve? If this seems like a stupid question, don't take any offense. Some people just don't know that there is even such a thing on these motors...
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Old Oct 8, 2004 | 10:03 PM
  #25  
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Won't a breather system actually cost you horsepower? The PCV system creates a vacuum that helps keep crankcase pressures to a minimum, and that helps to keep all the parts moving smoothly, right?
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Old Oct 8, 2004 | 10:15 PM
  #26  
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Tis true, as well as seats the piston rings against the walls for good overall cylinder pressure. Removing the vacuum sorce should worsen blow-by wich reduces cylinder pressure (power), and will also contribute to the contamination of that expensive oil...
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Old Oct 9, 2004 | 03:49 PM
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Yeah I changed the PCV valve a couple months ago. Guess I just didn't do a good job sealing the cover where it meets the oil pan. Would red RTV work better than the black stuff? Don't feel like doin it again but this will give me an excuse to throw a bigger cam in there.
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Old Oct 9, 2004 | 10:57 PM
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Even the cheap blue stuff would be fine for that app. Try to let the stuff sit for an hr before actually bolting on the front cover. Allowing it to dry somewhat before applying torque will promote a better seal.
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