Engine- Exhaust Manifolds

[cv70chall]

I recently had a 440 Engine upgrade done to my 70 Challenger. We opted to go with HP Exhaust Manifolds over headers and everything seemed to go together fine.
The Motor is a 1977 dated block (440-6) style with factory heads.
We used HP manifolds #875 on the passenger side (dated 10/71) and 337195 on the drivers side (dated 3/72).
I've experienced excessive heat from the manifolds and a recurring valve cover gasket leak that always crops up on the rear corner passenger side- no matter what type of gasket (cork, fiber, carbon-X) Ive tried and no matter which cover (stamped, aluminum or recently date correct.

What the hell am I dealing with here?

-HELP-

Motor temperature stays between 170-200 on average. Runs good.

??

[burdar]

You mentioned this problem in another post and I replied to it with a link to a better gasket.  This is a common issue with the factory manifolds.  You need to buy the gaskets that this company sells.  They won't burn like everything else.

http://www.superformanceproducts.com/

[cv70chall]

No, actually the last set I used were the SUPERFORMANCE CARBON-X Valve Cover Gaskets that said they could
"handle all the heat my HP manifolds could dish out."
Spent $32 on them and no luck.
-Not the case...as the back corner of the passenger side basically cracked from the heat. It's nuts.  I'm at the point where I would try something that can be applied with a brush that would dramatically lower the manifold heat output near the valve cover.
(something spray-able)

Any ideas? I'm FRESH out- and DON'T want to have to go with headers (and their inherent problems) unless absolutely needed.

[cv70chall]

I'm fairly certain the manifolds are correct for my engine as well.

[burdar]

Did you contact them and let them know that their gasket cracked?

You can send your manifolds out and have them ceramic coated on the inside and out.  That will reduce the temps quite a bit.

[Racer57]

The oil leak issue on the passenger side is not uncommon. When you have the cover off, take a good look at the area where its leaking and you will see theres not much of a seating surface.  I had that problem with my stock valve covers. I switched to cast aluminum ones and used a Moroso gasket   http://www.jegs.com/i/Moroso/710/93055/10002/-1   Since I do not plan on taking them off again, I also used hi temp gasket sealer on both sides of gasket.  No more problems.

[cv70chall]

The Moroso rubber/ steel core gaskets were actually one of the sets I tried- with aluminum covers- and no luck. The heat from the manifold basically baked/ shrank the rubber in that area and began leaking.
Is there anything I can apply for heat reduction BY BRUSH so I don't have to remove the manifolds?

[bc3j]

I did an unconventional method of sealing mine. I have a 383 HP using stock manifold and valve covers. My mechanic suggested using Permatex Right Stuff without a gasket. The heads and valve covers were cleaned and dried before applying. Heads and valve train were checked and re-torqued before sealing. Difficult to get back off, but I have an oem valve train and don't have the check the valves. No leaks in two years. Probably not a solution with solid lifters.

[cv70chall]

We did some temperature research yesterday.
Engine temp nominal.
Temperature at Intake/ Block is about 280.
Temperature at Exhaust Manifolds is about 480. This would explain why I'm baking gaskets I guess.
Went to check the plugs the mechanic had installed and they are 5/8" and not 13/16". We dug further and the motor actually has 400 Heads on it.
It runs nice and strong- but- could these heads be running hotter- thus causing the manifolds to run hotter as well?

The more I dig, the more questions surface.

[Chryco Psycho]

the heads will no affect on heat , part of the problem is the valve cover surface is never flat , I assume you have tin covers which conform to the uneven surface better than cast alum . timing & jetting could cool the temps , you want timing at idle around 14* .
 A thin deflector plate installed between would help also bolted onto the manifold bolts .
 silicone will not burn through easily so a coat of silicone when the gasket is failing could help too ,

[cv70chall]

I'm going to partially back out the manifolds and replace the manifold gaskets with the heat shield gaskets, so there will be some deflector in place. I'm also going to apply some Eastwood Hi-Temp sealant/ paint on the manifolds- which will insulate them up to 600 degrees.
Reinstall the valve covers and then re-seat the manifolds.