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FE Power Forums => FE Technical Forum => Topic started by: ACHiPo on March 11, 2019, 02:54:23 PM

Title: Sealed PCV
Post by: ACHiPo on March 11, 2019, 02:54:23 PM

I need a totally sealed PCV system to get my CA specially constructed vehicle registration as a 1965 Cobra.  I have a PCV in one valve cover with a tube going to the intake manifold.  Will the engine run ok (at least temporarily) if I replace the other open valve cover vent with an oil fill cap (basically sealing it), or do I need to run a tube from the other valve cover to the air cleaner?

Title: Re: Sealed PCV
Post by: WConley on March 11, 2019, 03:43:48 PM

You do need make-up air for the crankcase.  Otherwise the PCV will pull a strong vacuum and you might compromise a crankshaft seal...

If possible, run a hose from the other valve cover to the air cleaner.  If that's not possible you'll have to get creative to pass the test.  You could run a hose up underneath the air cleaner and make it look like it goes in, or you could fit the hose loosely on the fitting going in to the valve cover so it leaks. 

You don't want vacuum in your crankcase, so if you can't properly plumb a line to your air cleaner then you need a leak.  If it's just temporary you should be OK.

Title: Re: Sealed PCV
Post by: C8OZ on March 11, 2019, 03:44:42 PM

You'll need to relieve the vacuum somewhere, or it will suck in gaskets. Plumbing the second valve cover to the air clear housing should be a good answer, I would think. edit: I'm way too slow.

Title: Re: Sealed PCV
Post by: Heo on March 11, 2019, 05:23:17 PM

Why it goes to the aircleaner is to
suck clean air in to the engine
easy to drill a hole under the cleaner
and fit a tube

Title: Re: Sealed PCV
Post by: Phil Brown on March 11, 2019, 06:23:15 PM

If I'm not mistaken in Calif.with the PVC, the other valve cover has to be vented to the air cleaner. It can not be an open breather.

Title: Re: Sealed PCV
Post by: ACHiPo on March 12, 2019, 04:20:19 PM

Thanks for the answers.  Looks like it's back to Napa for a valve cover fitting, a PCV hose and grommet for the base of the air cleaner.  The oil fill cap seemed to easy to be true.

Title: Re: Sealed PCV
Post by: ACHiPo on March 14, 2019, 07:14:53 PM

One other question--I've heard the inspectors are sticklers for the correct "PCV" hose and you can't use fuel line.  Is there an online source where I can get the right elbow and hose, or am I best off just heading to the auto parts store?