79 vette 383 stroker problem with leaking valve cover gaskets

Q.  I have a 79 vette 383 stroker. For some reason I can’t seem to solve a problem with leaking valve cover gaskets. The leak is coming from the left rear of the engine. The gaskets have been replaced several times within a short period of time.

A. The type of gasket makes a big difference. If you’re using old fashioned cork gaskets — good luck. But if you’re using modern composite gaskets you should check for porosity in the sealing surface of the head. Using a machinist’s straight edge, check the sealing surface of the valve covers to make sure the covers aren’t warped from over tightening and yes aluminum warps when improperly tightened. If everything is mechanically correct it comes down to something you’re doing wrong.

One very wrong thing that do-it-yourselfers and techs alike do is begin adding RTV or some form of gasket akum-pucky to seal something that doesn’t need and shouldn’t have sealant. Unless there are specific instructions with the gaskets do not add sealant of any kind to a gasket as it will almost always cause leaks.

Then of course there are those who think if a little bit is good a whole lot is a whole lot better. In this case I’m talking about torque. Using an inch pound torque wrench torque the valve cover bolts to 36 to 40 inch pounds or slightly more than finger tight. Finally the valve covers are steel make sure they have the proper torque spreaders on the bolts to even out the force applied by the bolts.

Originally posted on National Corvette Owner’s Association newsletter http://www.nationalcorvetteowners.com/

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