Just need to change a valve cover gasket on the 65 390. Should I use cork or rubber? Im just getting them at auto z- so is there a brand I should use more than the other? How tight do you put the valve covers on?
I have always used cork. No real reason. It just seems to be what I always end up with. What I do is use gasket tack to "glue" one side of the gasket to the valve cover. Has worked great for me and I remove the valve covers more than the average bear since I have to check my lash on the solid cam every so often.
Do not crank the valve cover bolts down real tight! It will deform the gasket and cause it to slip an leak. Not too tight. Most likely a little looser than you think. Also check them after a few days as the gasket will compress. If they're not leaking then don't mess with them. I learned the hard way.
Yeah, so did I. I used rubber ones and thought "should have a great seal" and I now KNOW I tightened them to much. All that work on a 79 mercury with all them tubes and stuff and my valve cover still leaks. I think I even ended up warping the cover from torqing them too much. So sad I am about that. I wondered if rubber was really good for how hot a FE engine could get.
I prefer cork. Put them on dry. When the oil hits the cork they will swell and seal right up. Cork gaskets are designed to be installed DRY only....no sealant, glue, etc and it helps to have both surfaces dry and clean.
Cork and rub grease on both sides, the grease act's as a glue... keeps them in place and swells the cork.
Grab your index firger before the second joint, twist till' it hurts... that's about 8lbs.... Apply that to a 1/4 in. rachet with the ext. between the your index and middle finger..... Wha' la'... no more leaks....
All most forgot... pean the bolt holes on the valve covers (or transmission pan) flat every time you put them back on... unless they're Aluminum