1972 - 40 with F engine. Original exhaust manifold had cracks showing in 2 places. I understand many of them ended up cracked. I've got one in decent shape, now cleaned re-tapped & lightly sand blasted, made a new stainless heat riser valve assembly. If heat is the enemy of these castings would it be better to leave it raw and not add a layer of paint? My guess is they were originally installed with no coating. Maybe it was for a reason.
Exhaust manifold, paint or not?
- Thread starter Cleg
- Start date
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I think the heat from the exhaust will burn off most paints.
the cracks are from being 1 piece and all the heating/cooling cycles.
the newer style is 3 piece and has some "give" to it to avoid cracking
the cracks are from being 1 piece and all the heating/cooling cycles.
the newer style is 3 piece and has some "give" to it to avoid cracking
Have it ceramic coated....
These coatings possess excellent thermal barrier characteristics, providing a dramatic reduction in radiated heat. This means reduced under-hood temperatures, accelerated exhaust gas velocity and a longer life expectancy for the entire exhaust system, not to mention their chemical and corrosion resistance.............
These coatings possess excellent thermal barrier characteristics, providing a dramatic reduction in radiated heat. This means reduced under-hood temperatures, accelerated exhaust gas velocity and a longer life expectancy for the entire exhaust system, not to mention their chemical and corrosion resistance.............
Ceramic coating would be awesome but expensive. I rebuilt mine two years ago and sandblasted the exhaust manifold and bead blasted the intake manifold. I left the intake bare but used CALYX on the exhaust manifold. It has held up well for a few thousand miles. I thought it still looked great until I went and took this picture. Then I realized it doesn't look as good as I thought.
The beauty part of CALYX is that it wipes on like grease. I can put more on it now that I know it needs it but I don't have to tear it down and reblast.
The beauty part of CALYX is that it wipes on like grease. I can put more on it now that I know it needs it but I don't have to tear it down and reblast.
I painted mine with high temp manifold paint, I only have about 500 miles since my rebuild, but so far I am very pleased.
High temp paint burns off over time. I say leave it rusty, or have it jet hot coated for heat purposes.
I painted mine with that high temperature ceramic paint from the auto store good to several 1,000 degrees according to the can. Made for manifolds not the 500 degree exhaust paint. So far so good, I think these newer ones hold up a lot better. I have also herd of curing them, like you would cure a cast iron frying pan. Give them a good oil rub down and then let that burn off, helps slow down if not stop the rust. You have it off and clean, might as well paint it, a can is cheap seems to last, and at a minimum will keep it nice for a while.
Maybe, but the VHT flameproof 2000 degree stuff last for years. This is when it was new and it looks about the same now. It did not last on the air rail, however.
I filled my little cracks with Permatex 26346 Hi Temperature Metal Repair compound. Seems to have worked great so far (5 years).
I say go for it!
