Over the winter I'm going to install a set of Sanderson Headers on a small block chevy. Sanderson tells me that no exhaust manifold gaskets are necessary and recommend Permatex Ultra Black sealant. I'm ex Navy power plant mechanic and 50 years in industry. Every situation I have ever encountered with exhaust manifolds required a gasket. When I asked the Permatex people about Sandersons recommendation in using the Ultra Black, he replied "I wouldn't, it's only rated for 500F max". I can understand that they might be the flatest flanges there are, but cast iron heads aren't ground perfectly flat, they are "fly cut", hence the stock gasket. Am I too old school?
Cheap header gaskets(like the ones you get in standard rebuild sets) will eventually leak but I can't see where a quality gasket will hurt anything.
Some GMs used gaskets, but most Chevy V8s with iron manifolds didn't. They did have lock tabs, to keep the bolts from loosening, on the outer 4 bolts on small blocks, and interference fit threads on the bolts on big blocks. If the mating surfaces are flat, and the header flange is thick, and you can keep the bolts tight, gaskets (or RTV) should not be necessary.
I know quite a few people that use ultra copper with their Sanderson headers without any trouble. I don't know of anyone using black. Personally I use SCE copper gaskets on my car but the headers are not Sanderson but rather, FPA
Look into Percy's header gaskets. I have used them on several cars and they work great. They don't look anything like other gasket materials you are used to seeing... They are actually kind of fuzzy. I used them on my OT AMC 360 and they never burned out between the center ports like they others I tried.
If the fit between the two components is good there will be good heat transfer between the two surfaces, so the sealer, if used, shouldn't see much more heat than that of the cylinder head. In other words, the manifold surface shouldn't be much hotter than the head surface.
I have Sanderson's on my Red Ram. Used Permatex red hi temp RTV, followed Sanderson's instructions allowing the RTV to skim up before installation. Been running 2 years now leak free.
I bought a set of Sanderson headers last year. They specifically state: Do not use a gasket because it can cause the flange to distort. I followed their directions. Put 1/8" bead of red RTV on the head. Let set over night. Then install header. Been on there a year and no leaks. I had a sealing problem with a set of homemade lakestyle headers on another car. Tried this method and have had no more problems. I would not second guess Sanderson's directions. It works.
For what it's worth, I used to use a thin skim of graphite grease between exhaust manifolds and heads when not using a gasket. I don't recall now where I heard this recommendation, it was a long time ago. It worked very well.
I get the powerplant part. I would not use rtv either. I love the remflex gaskets. 10+ years and no leaks. I'm sold.
wbrw32, when the people that make the sealant, Permatex, tell you that the would not use the Ultra Black then I would take their advice. There is no reason to call people a dumb *** and hope it never seals. Try to act like an adult. Lots of other good advice from others. I'll go with the red or copper.
Hey he is a self proclaimed parts spe******ts from the "traditional days". From what I have seen is that this guy doesn't know **** other than how to be an *** to others. I don't think he really knew anything in his day and it seems to be the same today.
Those tabs were GREAT for catching a p***ing knuckle.... I have never used a gasket (most gasket sets come with them..) on a SBC with cast iron exhaust manifolds. Make sure everything is clean, run a flat file over the mating surfaces just to be sure. I would tend to side with Sanderson's advice. When in doubt in the past on oddball installations, I've made up copper gaskets and that always worked. I've also used this copper spray from Permatex, it says it stands up to exhaust heat in the ad. https://www.permatex.com/products/g...rmatex-copper-spray-a-gasket-hi-temp-sealant/
Have installed quite a few sets of Sandersons on small blocks and used either the black stuff they recommend or the copper stuff--none have ever leaked if installed per instructions-maybe I'm just lucky
I have used Permatex blue, red, and copper on header/manifold gaskets over the last 40 years, and never had an issue. I like to snug headers up, and give them a final torque the following day, although I have been guilty of just tightening them up on installation and running with them. That has been my honest experience. Like some of you have mentioned, on sbc's, I will run manifolds without gasket if the surfaces are good enough to do so. RTV, like thread tape, can be your friend, when used in moderation.
Seems odd they would recommend Ultra Black when Permatex states it is for gaskets and oil resistance up to 500 degrees and Ultra Copper is recommended by Permatex for exhaust gaskets and is rated at 700 degrees. I use the copper and would recommend it over the black although I have never used the black on an exhaust . I use Percys soft gaskets on my stuff and reuse them with a little Ultra Copper and have no leaks. You may have to try some of these recommendations and see what works for you.
Are the Sanderson flanges different from the norm? Been reading the advice above, I have ******s on a SBC. Every set of headers I ever bought came with gaskets...and many failed.. The rebuild gasket set I have has the ones with metal on one side, paper on the other.
The exhaust gaskets in a SBC gasket set are an interesting item....Chevy didn't use gaskets on the manifolds (with iron manifolds), but the gasket companies make gaskets for them. I don't understand it all. For typical headers, I would use the composite graphite gaskets, such as Fel Pro 1404 or 1426. Make sure the hole in the gasket is small enough that it seals all the way.
Used red RTV on nitro engine at Bonneville with no problems. We us a 3 piece aluminum gasket on our dirt rear crossover headers and get 2 seasons out of them.. They need tightening after every race.
"The exhaust gaskets in a SBC gasket set are an interesting item....Chevy didn't use gaskets on the manifolds (with iron manifolds), but the gasket companies make gaskets for them. I don't understand it all." Same with Ford. But then someone will eventually install gaskets, and with age the gaskets will partially crumble away. If the missing gasket material is under a bolt "ear", then next time the bolts are tightened there's a good chance the ear will be broken off.