Valve cover leak

[thorconstr]

Any of you guys have a fool proof method of stopping a valve cover leak on a 427 SO? I always clean the cover thoroughly, apply Hi-Tac to the cover and corresponding side of the cork Felpro gasket. I don't over tighten, I re-tighten after running, and check with use, but sometime the SOBs leak. Any suggestions? Thanks

[blykins]

It all depends on how big of a step there is between the intake and the head. Generally, I use a cork gasket, put a little RTV on the joint between the head and intake, then smooth it out so that it takes the step out. Try to make it a smooth transition, so that they are level with each other. I don't use any adhesive at all on the gaskets and just tighten them by hand.

It also helps if the heads don't let the oil pool in the top end.

[thorconstr]

Thanks Brent, I'll give that a shot!

[Michael C Henry]

Old school . Back in 67, If the heads and intake are milled to fit .the ports in heads, manifold, and gasket all line up and the top valvecover gasket rail is one flat almost even ring. The two small top gasket tabs protruding from the intake manifold to head joint on each head are carefully peened over , that has allways worked for me. I used oil resistant RTV. clean valvecover gasket surface with something like braekclean. I glue the valvecover gaskets and cover together like I was never going to remove them ( you want the gasket to stay with the cover), bolts can be used to keep everything in place . after some setup time I place a thin layer on the gaskets let skin over the I mount the valvecovers and lightley tighten the bolts. After letiing the TRV set up I can evenly snug the valvecover bolts a little more and run the engine to see If I have been scccessfull.
The red or orange RTV is a higher temp than blue RTV both are oil resistant. The red or orange also set quicker than the blue.

[patrickt]

Originally Posted by thorconstr

Any of you guys have a fool proof method of stopping a valve cover leak on a 427 SO?

How much are you leaking? You know, three drops or less on an FE is considered bone-dry.

[Ronbo]

Since the FE has part of the valve cover seat on the intake I'd glue the gaskets to the block side and leave the valve cover side dry for removal.

Even though you probably have cast covers, check the gasket surfaces with a streight edge. (especially around the bolt holes) Check the block side as well.

Another trick is to stack two gaskets, gives you more compression range. (or see if you can find extra thick gaskets)

Could be worse, like a small block Chevy. Been there.

[rokndad]

My experience is similar to M. Henry. If you're using the chrome pentroof covers, make sure you use the speaders on the bolts. The covers we seem to be getting are a lot thinner than the OEM's and don't spread the load evenly around the perimeter of the cover. Mine leaked like crazy and there was nothing I could do to seal them up. Massive puddles on the floor after a run.

Finally went with the cast Shelby covers (or any other cast flat edged cover will work as well) and RTV'd the felpro Cork rubber impregnated gaskets to them, let them sit overnight and then bolted them up. Made sure to put a little RTV on the gaps between the head and intake. Not one drop since and my garage floor is clean. Perfect!

[SuperHart]

I found a company that makes a great set of gaskets, extra thick for better sealing. Go to "http://www.dscmotorsport.com/" to purchase.

[427 S/O]

Al, like they all said, I use a small ball pien hammer to flatten the intake gasket between the head and intake then add a small amount of RTV (gray). NAPA has some rubber gaskets that work really well. If I missed it in above post, don't over tighten, most folks do when the leak won't stop. One little trick I played with that helps, use lock nuts, run them on and off to loosened a little then tighten.

[slithering]

Al,

Are you sure it's the valve cover and not the intake? 427's are notorious for leaking at the back of the intake where it seats on the block. The number one problem most make with RTV, they don't allow it to cure before restarting the engine. I let mine set overnight before firing it off.

Chris

[thorconstr]

No, I finally have the intake leak solved with Toyota Oil pan/Camshaft housing sealant. That stuff is awesome. I'm going to put another new set of Felpro gaskets on today and see if that does the trick.

[undy]

Right Stuff?? It has a much higher compressive load rating that RTV.

[thorconstr]

Super, I am going to order those gaskets on Monday, Thanks

[Barry_R]

Victor has a cork faced valve cover gasket for the FE with a steel inner liner to keep it rigid and in place. Nice part that nobody knows about. Use the gray RTV - Motorcraft or alternative - the gray is oil resistant and dries firmer for a stronger seal. I try to snip off any gasket that protrudes above the rail. I use the RTV very lightly on both sides of the gasket. Can somebody please explain why they have three bolts on the upper side of the cover and only two on the lower end?

[Anthony]

Originally Posted by Barry_R

Can somebody please explain why they have three bolts on the upper side of the cover and only two on the lower end?

To me, it apears that the bolts are evenly spaced around the rail, with the two upper outer bolts, on the end rail, just below the top rail, maybe to get better clamping on the ends, right near the head-intake transition, and then two bottom bolts for clamping on the bottom, like a sbc.

[Michael C Henry]

I just tried a set of the neoprene gaskets with the steel reinforcement inside. I bought them several months ago off eBay. Problem was the holes were high causing the gasket to be low. Holes were also a little small. Once pushed over the studs it was a real chore to get the gasket back up.. As a cure I used a moto tool with a 1/8" carbide rotary file to exagerate the holes downward. The three holes in the manifold were slotted the most. They seemed the most off, probably because of having the intake manifold milled to match the heads. I used the blue RTV . If it doesnt work it will be easier to remove and apply something else.

[Michael C Henry]

I used the steel reinforced neoprene valve cover gaskets. Problem is the holes in the gaskets were high in the gasket making the gasket set low on the head. plus the holes were so tight that once I pushed one gasket over the studs , it was a ***** getting it off. If the gasket bends ,the gasket gets even tighter, hard to emagine. Plus there was no fudging for the manifolf being milled to match the milling on the heads. I ended up taking a dremel moto tool and 1/8' carbide burr (rotary file) to the gasket holes. I exagerated the gasket holes downward and getting the needed freedom and moving the gasket upwards to cover th upper sealing edge on the intake manifold. Plus a little blue RTV. It isn't leaking from the valve cover anymore. Now the oil is showing up on the right coolant pump to block flange boss. It's making a real mess maybe not as much as before but enough to worry about.