You may have missed this information in previous threads, Stuey. The subject has come-up numerous times, but this is one of the more recent replies from Ted.

Ted Eaton wrote on 12/19/2013

The problem is not so much the heads and/or the gaskets but in the use of cast iron exhaust manifolds. Using gaskets in conjunction with the cast iron manifolds does speed up the frequency of broken or cracked manifolds. A thin film of hi-temp RTV in lieu of using any form of exhaust gasket seems to prolong the life of the manifolds.

With the exhaust manifolds being machined flat at the head mounting surface, then a thin film of RTV should suffice. For the same reasons the manifolds break when using gaskets with the iron heads, the manifolds will also break or crack when using them on aluminum heads with gaskets. Keep in mind that the exhaust manifolds for many of the as-delivered Ford engines did not use any form of exhaust gasket at the heads and simply relied on a good metal to metal fitment.

Again, this subject appears in multiple threads in the Forum 'SEARCH' archive. The message is consistent, gaskets used with cast iron exhaust manifolds result in heat transfer problems that invite breaks at the exhaust manifold to cylinder head attachment points.

Hope this helps.

Hmmmm… Interesting point regarding corrosion of the aluminum heads, Stuey.

Regarding cast iron, don’t let the thickness of a cast iron section mislead you. Cast iron is brittle and uneven heating causes uneven expansion resulting in cracking. OUCH!

While composite gaskets may be supplied with the exhaust manifolds, consider an alternative for eliminating the potential corrosion issue resulting from the dissimilar metals being in contact.

Suggestion… apply a smear of Never-Seez to the exhaust manifold flange surfaces instead of RTV gasket sealer. In my experience, the Never-Seez has seemed to seal the joining surfaces.

Regards,

Never-Seez won’t form a gasket in the true sense of the word, Darrell. It will fill S-M-A-L-L gaps. The exhaust manifold flange surfaces need to be basically true. As you indicated, it never really hardens,but in my experience does become more paste-like over time due to heat exposure drying out the liquid ‘carrier’.

I use a prudent amount of Never-Seez on exhaust manifold to cylinder head mounting bolts. I use a more generous amount of Never-Seez on the exhaust manifold stud threads that secure the exhaust head pipe to the manifold. While Ford used brass nuts in production assembly for securing the head pipes to the exhaust manifolds to try to make them easier to remove when necessary, when the steel studs rust and become corroded as they do with time, the brass nuts are still miserable to remove if Never-Seez wasn’t used during the exhaust pipe installation.

With JM’s aluminum heads, I recall Ted writing a caution regarding using Never-Seez on spark plug threads. My take-away understanding from the posting was, ‘Coat the spark plug thread surface; DON’T fill the threads. Excess Never-Seez can ‘crystallize’ or cake-up (my words) on the end of the plug exposed in the combustion chamber and make removal of the plug difficult’.

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A friend uses Molybdenum disulfide grease instead of Never-Seez when mounting cast iron exhaust manifolds on y-blocks. Molybdenum disulfide is silvery-black in appearance. In both looks and feel, Molybdenum disulfide is similar to graphite.

At one time, Molybdenum disulfide was the lubricant supplied with many new camshafts as THE assembly /break-in lubricant. I don’t know what is in some of the camshaft installation lubes being sold today.

It sounds like I read Ted’s posting in haste and that my rec-collector isn’t helping the situation either. Thanks for coming in on this Ian and Mark regarding potential metal interaction between the copper in SOME anti-seize compounds and aluminum, and the use of anti-seize materials with plated spark plug housings. I hadn’t registered on the effect of anti-seize compound on correctly torquing spark plugs OR the consequences of interfering with manufacturers’ purpose in plating spark plugs.

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Too, it sounds like there are different formulations of anti-seize compounds. I’m using the ‘Never-Seez’ brand, catalog number NS-160.

The display advertising label on the can calls it an ‘anti-seize and lubricating compound’. At the bottom of that label it is tagged an ‘extreme pressure lubricant’. The same front label proclaims the product to be for ‘protection against: -extreme heat…over 2,000 *F, -corrosion, -seizure, -galling, -rust, -carbon fusion, -galvanic pitting’. The ingredient make-up of the product is not given anywhere on the can.

In the listing of potential application categories AND specific uses for the product on the back of the can, under ‘general’ it is recommended for use with ‘steel threads to aluminum or magnesium castings; Stainless steel to stainless steel threaded fasteners’.

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Again, kudos to Ian and Mark for not letting what I wrote stand to be read by others as applying to ALL anti-seize compounds and Mark, thanks for correcting my incorrect recounting of Ted’s earlier posting of information about the use of anti-seize compounds on spark plug threads.