coating headers

[kickarsgrdam01]

i have been looking at headers and to get just raw headers is like $150 cheaper then the coated, i know the coated will help keep the rust off and keep them cooler but is that really work that extra money. what if you took some high temp paint ( probably the 1300F) and painted the headers, that would cover the metal and keep them from rusting right?? and i know the temp will make you loose a little power after they heat up but still. if there another way to coat them besides paying $150 for them to do it?

[rixGAphx]

In general, passenger cars have thick cast iron exhaust manifolds that are just allowed to rust; no big whoop.

Headers are generally thin, mild carbon steel that will corrode easily, both from water on the outside and on the inside from water (condensed vapor from the exhaust) and acids (that fom in minute amounts from the exhaust.

Headers need to be coated both inside and out to prevent corrosion.
If it's a paint product, it needs a compatible primer on the bare steel.
To get protection on the INSIDE, you virtually have to dip-prime/paint the assembly. That would require several gallons each of primer and paint to fill a tub large enough for dipping. $$

A manufacturer can easily coat the header with ceramic by dipping the units then baking them.
Or they can powder coat them, which has an electrostatic charge on the metal that attracts the sprayed dry paint particles to the metal, inside and out; the assembly is then baked to 'melt' the dry paint into place.

If you plan to own the vehicle a while, spring for the factory coating.
DIY coating won't protect the inside enough to prevent rust-thru for more than a few years.

Good luck.
-Rick

PS: The 'insulative effect' of a coating is for lower underhood temps and less heat thru the firewall to the cabin, not particularly for optimizing performance of the headers.
On a turbo, you want to prevent heat loss between the cylinder and the turbocharger, so insulation is good.
On a naturally-aspirated vehicle, heat loss all the way to the back of the vehicle is no problem, so insulation is of little performance value.

If you're really concerned, there are adhesive insulative wraps for headers. If the header is clean when the wrap is applied, it will prevent rusting from the outside. But the interior corrosion is still an issue.

[92CamaroRS]

buy the headers bare, send them to jet-hot and have them coated and get a lifetime warranty! simple. might cost more now but will save money down the road. IMO its stupid to buy headers that are not ceramic coated.

[kickarsgrdam01]

wow....thanks a lot that really helped, i never thought about the inside of the headers rusting....thanks