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Manifold Gasket Dressing/Sealant Recommendations

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Michael Oritt

Michael Oritt

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I have a DW AL head and steel tubular headers with exhaust pipes 1 and 4 meeting at a collector which in turn runs down to meet another collector where the pipe from siameze'd 2 & 3 join in and on to the muffler, etc. The pipe from the 1-4 collector cracked and broke rather cleanly just below the Y joint and in order to get the top section out for welding I had to remove the carbs as well as the 2-3 pipe. Everything came apart cleanly and I was able to get all of the above off without damaging the metal gasket. In some places there appears to be remnants of what was probably an Ultra Copper-type sealant applied when I installed the head and manifold almost 20 years ago.

My question is: Should i put a thin layer of Ultra-Copper or something similar on the outer face of the gasket or simply go directly to reassembly?
 
I don't use anything on the metal gaskets. I was taught back in the '60s that the purpose for the metal face on the gasket was to allow slight movement as different metals expanded and contracted with heat - could be an old wives tale, but that's the way I was taught. Having said that, I do use spray copper on the head gasket though..... I'm interested to hear what others say.

Dave
 
Michael,
I see the gasket is under $5.00. Wouldn't it be a good idea to use a new gasket?

Maybe they have them in stock at Healey Surgeons. In any case, Moss is back open.

I'd be tempted to spray both sides of a new gasket with copper spray.
 
I have never used any exhaust manifold sealant on any of my Healey (6 cyl) race motors and never had a problem. I believe that is due to a couple of things. The flanges on my headers are true and of substantial thickness ( 3/8" ?). Also, because of the good quality and composition of the intake/exhaust manifold gaskets we have available.
In the case of headers on some American V8 motors I have had to use a sealant. I have used the red hi-temp RTV sealant with good results. As for intake manifold gaskets, I have never used any type of sealant on any motor and never had a problem.
 
Guys--

Thanks for the responses and notwithstanding input from those who said they do not use any gasket dressing for this application I have decided to spray a light coat of Copper sealant on both faces of the gasket. No offense I hope, and as I like to say "Take my advice--I'm not using it".

I had to remove the carbs (attached to the intake manifolds) to get the tubular headers off and back in place and this morning as I was about to remount them I noticed that while there was a paper gasket on the inner face of the front intake manifold (where it contacts the long one-piece gasket on the cylinder head) there was none on the rear intake manifold. Obviously things should be the same for both front and rear and I simply wonder whether there ever should have been a paper gasket there in the first place and was its inclusion an error I made when I last had things apart, etc. or did I omit one? FWIW the Moss catalogue does not show any gasket between the intake manifolds and the head except, of course, for the long one-piece gasket that seals up both exhaust and intake ports.

I do have a second paper gasket on hand and I could either remove the one that is on the front manifold or add the spare one to the rear manifold and if that is an error at least now things will be symmetrical. I know I cannot expect consensus but I will go with the majority opinion from the first five responses. Thanks in advance!
 
I would check the flange thickness of the intake manifold and the headers to see they are the same.

Where there is a common stud with a washer spanning the gap between the two manifolds, that spanning washer can apply different clamping forces on the two manifolds if they are uneven.

I have seen extra gaskets used as shims to simulate the same flange thickness to insure adequate clamping forces on both.

I have also seen stepped washers (one half of the washer a different thickness than the other half) used for the same purpose of clamping equally.

Just a guess.

Dave
 
Mike, I second Dave's caution. I carelessly broke a mounting ear on an intake manifold because of uneven surfaces when using headers. Not saying that is what is happening in your case, but worth checking.
Lin
 
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