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Vindictive

Leaking Valve Covers

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My valve covers leak. I hate seeing it on the motor after I cleaned and painted the engine last year when I had the heads done.  When I pulled the valve covers I noticed they were a bit mis-shaped. I read that this is pretty common and the solution I found was to put them in a vise and gently tighten until they are back in shape.  This worked fine, it didn't take much effort to get them squared back up nicely. When everything went back together, I noticed that before my torque wrench would click (only 4-5 ft./lbs.) that the base of the covers were already starting to squish back out. I didn't want to keep cranking so I stopped, they seemed snug , but they've been leaking. Should I entertain looking for another set of valve covers? The set I have seem solid, no rust, etc. but if they won't hold their shape it seems like there's a problem. I'm using cork gaskets, but would change to rubber if they'd be likely to seal better. 

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The vise trick works great.  Fatherbuick clued me in on that.  The next step is to look at the surface where the gasket meets the valve cover. Are these surfaces straight, flush and fully flat when placed on the heads?    Are you using any Permatex?   Cork works just fine if the mating surfaces are fully touching each other.    

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You squished the covers back to original shape.  Now, the edge here needs to be flat and 90 degrees to side of the valve cover.  The entire edged needs to be flush to the head.   Check all the edges.  Bend as necessary.  Permatex. 

 

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MrEarl likes this

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The sealing flange was 90 degrees to the side of the cover and flat all the way around. I checked them after I squared the sides back up using fatherbuick's vise trick before I put it all back together last year. I did use a thin smear of ultrablack on the side of the gasket that faces the valve cover. More to hold them in place than for sealing. The other side was plain cork (no sealant) mated to a very clean and dry surface of the head.  I hate using sealant on that surface. Mostly because I hate cleaning that surface up while trying not to let any little bits get into the valve springs and oil passages if the valve covers ever have to come off. Maybe I need to reconsider. 

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Straighten the covers, glue the gaskets to the cover with weatherstrip cement,  either use anaerobic sealer or cured RTV on the other side.

Anaerobic sealer:  https://www.permatex.com/product-category/gasketing/anaerobic-gasket-makers-flange-sealants/   ..this only cures where compressed and any that squishes out can be wiped off after assembly; you will have to scrape some if disassembled.

RTV:  use black high temp and let it cure (use red or blue if you want it to look like a chevy engine); completely cover the gasket except  the outside edge to seal the gasket from bleed through.; very little scraping if disassembled.

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