The blow-by on one of my Chevys is more than the PCV system can handle. Oil is leaking around the PCV valve, the breather on the other rocker cover, and around some of the gaskets. I want to rig up a temporary (until I rebuild or replace the engine) way of sucking out those oily vapors.

I was thinking of gutting the PCV valve and running a hose down to a nipple on the header collector. I'm thinking that there is actually some vacuum there most of the time (sufficient to evacuate the crankcase). Will this work? Do I need some kind of check valve? Is there a better way to do this?

 

I got no replies, so I'll try one more time...

 

If the PCV system is OK, and you really have more blow-by than it can handle. I would just run a breather to let the pressure out.

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82 camaro--original steering wheel, brake/gas pedals, seats--everything else modified
82camaro

 

Yes, the Header thing Will Work.




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60 Ranchero - Project ( Money Hole )
85 Sport Coupe LG4 - Daily Driver
Reader's ride -> My Ride

Just another Hot Rod kid, or thats what they all tell me.
Livin' the Stereotype

 

I've heard of this being done to help ring seal on race engines, but not specifically to burn off blowby on a street car. I know you need a checkvalve above the header so you don't get any exaust in your engine.

I've been curious about doing this too...there is a Jeep I work on with the same problem and I had thought of this to mak eit more livable....but I dunno if there are any downsides or other problems.

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"American made baby. 100% American iron. The muscle among the masses. My hero. Yep, you can take your ergonomically designed, space age, computer controlled, 4 door, cup holding map lighted split double wishbone split fold down retractable cargo covered moon roof piece of transportation and keep it. For I have felt the thunder. And I know the difference!"
JSP Motorsports
ICON Motorsports

 

Thanks, fellas. Does anyone know under what conditions there will be positive pressure in the collector? If I need to, I'm thinking of using a check valve from an air injection system, but don't know if the oil in the blow-by vapors will clog it up eventually or not. I'm also wondering if a modified PCV valve would work as a check valve...