Thread: PCV use
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Old 04-11-2008, 01:14 AM
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Cobra Make, Engine: KMP 184/482ci Shelby
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Nothing wrong with a PCV...but it's not always required. After reading the wikipedia article, I have reconfirmed my conclusion that I just don't need it.

I don't ford rivers with my Cobra.

Yes, I'm polluting the hell out of the atmosphere with this setup while I burn $4.00 a gallon out of a 40 gallon tank at 7-8 mpg...oh well, it's a Cobra not a Prius. A 482 Shelby arruminum block, 10-1 compression, big cam, 850DP...note in the pic below there is no film on the valve covers (and I don't clean them) after 8500 miles of track and road use. I do admit to a small FE ass drip...a cultural trademark in my opinion.

As Ron and others noted, the old road draft tube performed the same function before the advent of the PCV valve if you had it set up correctly, and that is how the oil separator tank on the firewall of the 427s were set up. Sometimes folks call it a puke tank...it's not. It's more of a Rube Goldberg breather. Funny thing is...it works. A puke tank will simply hold what goes into it.

That old black lawn mower gas tank was configured so that you had the gases sucked out of the back of the manifold into the tank (another line sucked gases from the trans and the rearend). A bit of wire mesh in the manifold fitting traps wet vapor. On the passenger side of the tank, the top hose carries gases down a tube which ends just below the frame so that the airflow sucks them out (ie., the road draft tube). Another tube located at the bottom of that side carries any accumulated oil back down into the oil pan into that extra fitting next to the oil dipstick tube on Aviad pans. [BTW, the red/blue fitting covered in a heat sleeve line coming out of the back of the block allows for the external adjustment of oil pressure with an in-line fitting further down the line...it also runs down to the oil pan. Has nothing to do with the breathing system.]

In addition, and just for personal preference, I run a big K&N breather on each valve cover. Each of the holes has a plate below it to prevent splash (same as you use below a PCV). I never have any oil slime on my LeMans covers. I suspect the K&Ns do the same good job keeping the oil film in as they do filtering air before it goes down into the carbs.

Like I said, nothing wrong with a PCV, asspecially if you don't have the old style oil separator tank setup. There are many ways to skin a cat. The guys at Shelby came up with a damn good way in the 60s, so if it ain't broke...

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Last edited by Jamo; 04-11-2008 at 01:53 AM..
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