Ceramic Coat m42 headers

[robrez]

I've got a spare e30 318is exhaust and I was considering ceramic coating the headers to reduce the overall under the hood temperature. But I'm wondering if it would make much of a difference. I believe the OEM headers are cast iron, unlike most of the aftermarket headers which are stainless steel. If so, they shouldn't get hot enough under normal driving to warrant coating or wrapping them. What does r3v think?

[SkiFree]

My data point is coming from dailying my little 2002. Started with the stock cast-iron manifold. Engine was fine, but sometimes a bit on the warm side. Installed a ceramic-coated steel "shorty" header and recorded 8-12 degree drops in the engine bay.

My two cents, the ceramic coating is a great way to lower underhood temps even when compared to the already-pretty-heat-tolerant cast iron manifolds.

[digger]

yeah ceramic coating works well on thin walled stainless, i dont see why it wouldn't benefit a cast iron manifold. at worst the benefit is not as great as with stainless but it still looks really good so not a huge loss

[iwantspeed]

Do it

[varg]

The stock M42 header isn't cast iron.

[cunninglinguist]

I did it on my M42 and it made an appreciable reduction in underhood temps.

I did have some questions during one CA smog test because to the tech, the black ceramic i chose made the factory headers look aftermarket.

[varg]

Those visual smog inspections are criminally stupid