DarkKnight

Ive looked around and it seems people are divided on this issue with leaving them unwrapped seems to be slightly favored then wrapped. I bought a new set of LLP stainless headers and I'm wondering if I should wrap them or leave them unwrapped. I have a 383 LT1 with a SS ram air hood that has been modified to bring cool air into the engine bay and release some of the hot air. Any suggestions?
Thanks

Injuneer

Ask LLP if wrapping them will void their warranty?

DarkKnight

They don't offer a suggestion either way. Header wrap will not void the warranty but a coating will.

Injuneer

Wrapping the headers exposes the metal to temperatures they were never intended to see. Mild steel is a bigger problem that S/S because of the major loss of strength and increased corrosion at 1,000*F and increased cracking due to thermal stress and cycling. S/S is a close call.

There are mild steel header manufacturers who void your warranty if you wrap them. Worth checking on S/S with the manufacturer.

Just trying to help.

Chimera96

really?, I would think it would be the other way around.

MEAN LT1

I wouldn't wrap them. Looks like crap and will start to rust after a while due to moisture.

DarkKnight

Basically, it's considered an alteration or modification of the product if I should need to return for any reason. I suppose that makes sense when you think about it.

I would rather not wrap the headers. My only concern is too much heat frying a fuel line or a starter.

Injuneer

While I would agree with regard to appearance, not really with regard to rust and moisture. The external surface of mild steel will rust if you wrap it. It isn't from "moisture". The rust (scaling) occurs when the wrapped mild steel reaches 1,000*F, and the free iron in the metal begins to combine with the oxygen in the air = rust. Stainless steel resists oxidation.... that's one of it's benefits, in addition to retaining its tensile strength. It will "blue" at high temperatures, dull, and discolor but should not rust as seriously as mild steel. In a really high temp application, like nitrous or forced induction, wrapped stainless may be up to the point of corrosion... not really sure. It depends largely on the chromium content of the S/S. T409 has lower chromium content than T304, so it depends to a large extent on which stainless is used,

Cera-metallic coating mild or S/S headers should not be a detrimental process. It is not a chemical process. Does require removing oils and sand blasting. It's a mechanical bond and thermal fusing of the cera-metallic compound. These coatings were initially developed to protect the blades in gas turbines. Many header manufacturers offer both non-coated and coated versions of their headers. Do they refuse to warranty the coated versions? Directionally, a properly applied coating, on both the inside and outside surfaces of the tubes will significantly reduce the temperatures the metal is exposed to, and will significantly extend the life of the headers, with reduced corrosion and reduced thermal stress cracking. I know one manufacturer who coats has T409 S/S headers, but not the T304.

DarkKnight

Shoebox responded and said he does not like wrapping headers on street cars due to dirt, grime and oil trapping causing a fire hazard and it also causes metal fatigue by holding too much heat in.
As you already said as well...
Thank you. I appreciate your advice and all the quick responses.