Valve Cover Gaskets

[500stroker]

I am running an RB big block with Mopar HiPerformance cast aluminum valve covers. It seems like what ever I try they LEAK!
I have tried Moroso, fel-pro, 440 source gaskets they all leak on both sides of the engine, mostly toward the rear. I know I am not over tighting the hold down bolts , which are new. Clean surfaces, silicone, no silicone, new PCV, bigger breather it seems like I have tried all the tricks and they still leak. What the hell am I missing?
Any comments would be greatly appreciated - Thanks:thinker:

 

[WileERobby]

Ive used Indian head gasket cement for over 40 years, got them on my gaskets now, & not a drop leaking.

 

[benno440]

i use cometic valve cover gaskets, then use a bit of loctite red on each side, the loctite doesnt go hard just stays a thin film that seals any gaps

 

[khryslerkid]

Check them with a straight edge. Lay them on a flat surface too and check for a bow in them...

I like cork gaskets with some coppercoat spray on both sides. Removable later on...

 

[Mike Gaines]

Are heads IRON or Aluminum ?....stud/bolt hole angles are different on each

 

[MT_Mopar]

From what I've read these are some of the best available: http://www.summitracing.com/parts/MOR-93055

 

[Dennis H]

FelPro's work for me. Tighten, tighten tighten. 15 heat cycles.

 

[Sonny Black]

Sonny says, FelPro.....on my 4 bolt hole valve covers!...little Permatex blue (non hardening) works great, both sides... :icon_winkle:

 

[Propwash]

Fel-Pro's here as well.....I just use a little black 3M weatherstrip adhesive to hold them on to the valve cover side. The big kicker is Do Not Over-Tighten! Pretty sure that's what causes most leaks on valve cover's, oil pan's and tranny pan's.

 

[Car Nut]

I found the surface on the head in the back has a high spot, causing the cover to rock top and bottom.

 

[resq302]

Ive used Indian head gasket cement for over 40 years, got them on my gaskets now, & not a drop leaking.

I've done the same thing with using Indian Head gasket cement and the rubber / cork blend gasket and they seal up wonderfully. I also put a little bit of the blue medium strength lock-tite on the bolts / nuts to prevent them from loosening up or backing off from the vibration of the engine.

 

[500stroker]

Are heads IRON or Aluminum ?....stud/bolt hole angles are different on each

Iron heads with bolt fastners

 

[Canyon707]

From what I've read these are some of the best available: http://www.summitracing.com/parts/MOR-93055

used these but they failed to contain the leaking when I removed them they were actually cut form tightening. I was shocked to see it actually. Tried some felt ones also and they also leaked. this had been ongoing for some time now and have yet to remedy

 

[dvw]

Gasket surfaces leak because they're not flat. Over tightening trying to stop leaks destroys gaskets. The factory heads are cast and imperfect. The valve covers may be warped. However I have run many cast aluminum covers, none leak. First clean the surface. If the sealer doesn't stick, oil will weep between the sealer and the metal. Second, glue the gasket to the cover with 3M weatherstrip adhesive. Do not bolt the cover on at this time , let it cure. Now the gasket and the cover are one part. Spread a very thin coat of RTV on the head. Make sure it sticks when wiped with your finger, if not the head is still dirty. After making sure you have a thin .020-030" coating on the head run a 1/8-3/16" bead on the head it self over the original layer. The 1st layer was to make sure you have adhesion to the metal. Now bolt the cover on snug. DO NOT over tighten. A nut driver is usually plenty. Let it dry. You should have no leaks. My motors do not leak a drop.
Doug

 

[500stroker]

FelPro's work for me. Tighten, tighten tighten. 15 heat cycles.

I thought the idea was not to over tighten them?
Do you use a sealer?
Which FelPro gaskets?

 

[Canyon707]

Well I took a closer look at my covers and put a straight edge on them and they were all over the place. I took them to my maching shop and had them surfaced and trued up. Installing today.

 

[Dennis H]

FelPro. No sealer. Tighten the **** out of them. Heat cycle and cool down. Finally sealed...for a while. Chasing another unknown right now. Drivers side only problematic. 440.

 

[Canyon707]

FelPro. No sealer. Tighten the **** out of them. Heat cycle and cool down. Finally sealed...for a while. Chasing another unknown right now. Drivers side only problematic. 440.

I hope but machining them flat they work better. had a passenger side drip. I overtightened and it ruined the gasket.

 

[500stroker]

Gasket surfaces leak because they're not flat. Over tightening trying to stop leaks destroys gaskets. The factory heads are cast and imperfect. The valve covers may be warped. However I have run many cast aluminum covers, none leak. First clean the surface. If the sealer doesn't stick, oil will weep between the sealer and the metal. Second, glue the gasket to the cover with 3M weatherstrip adhesive. Do not bolt the cover on at this time , let it cure. Now the gasket and the cover are one part. Spread a very thin coat of RTV on the head. Make sure it sticks when wiped with your finger, if not the head is still dirty. After making sure you have a thin .020-030" coating on the head run a 1/8-3/16" bead on the head it self over the original layer. The 1st layer was to make sure you have adhesion to the metal. Now bolt the cover on snug. DO NOT over tighten. A nut driver is usually plenty. Let it dry. You should have no leaks. My motors do not leak a drop.
Doug

Thanks for the tips. I will try it.
I dig your 426 wedge motor that "Rat Roaster intake" is the Cats ***. Not to change the subject, do they make a Rat Roaster that will properly fit a iron head 440 RB block?

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I am running an RB big block with Mopar HiPerformance cast aluminum valve covers. It seems like what ever I try they LEAK!
I have tried Moroso, fel-pro, 440 source gaskets they all leak on both sides of the engine, mostly toward the rear. I know I am not over tighting the hold down bolts , which are new. Clean surfaces, silicone, no silicone, new PCV, bigger breather it seems like I have tried all the tricks and they still leak. What the hell am I missing?
Any comments would be greatly appreciated - Thanks:thinker:

Thanks for all the great info.
I am going to apply some of the methods, only time will tell if my leaks go away.
Thanks Again

 

[bigmanjbmopar]

One thing I have learned is to not overtighten about finger tight 15" lbs max. with the gasket rtv'ed to the cover and let set for 15 min bolt and go no leaks. Hard to believe but at times I check the bolts and they come a little lose even and still do not leak. goes against your gut but have to trust this. good luck.