Did you ever see this beautiful pic on Tom Byrne's website? This was before the header wrap caught fire and burned his car severely (this was a few years back). If you need more reasons than that (and many have been mentioned), then you are not listening.

 

ok so nix the header wrap...

Will the 1200* High Temp paint with ceramic in it do me any good as far as keeping the headers/underhood temps down? The kind you can get from AutoZone.

I need a fairly cheap way to keep from burning up my plug wires, I just got some MSD 8.5mm super conductors and don't want them to last about a week because of my headers burning them. I plan on putting in my headers and wires at the same time, along with a blaster coil.

 

The paint really won't effect underhood temperatures much. Coatings will. If you are looking to protect your plug wires, just get some fire sleeves or something comparable. Plug wires will burn if they come in contact with any header, including coated ones. The coatings help, but don't exactly make the surface cool.

 

what about useing header jackets. thats doesn't hold heat and lets air out cause it's a loose jacket around the just the top part of the header only about 10" down so thats plenty of air to the header right?

 

Maybe there is some confusion as to the purpose of the coatings. Header coatings do a couple of things:

1. They keep heat in (desirable) to keep your exhaust gas velocity up. A positive side-effect of this is that your underhood temperatures are kept lower.

2. The good ones at least, will help reduce corrosion. Especially those where the inside is coated as well. The coatings will keep moisture away from the steel on the inside and the outside.

Anything that has potential to let moisture sit against the steel will accelerate the corrosion. The header jackets will do this, though maybe not as badly as a wrap.

 

Yes, those header blankets, not the fabric ones, but the metallic ones that bend into shape are great for heat reflection. I've seen the Caddy's and Audi's LMP's use them on their turbo manifolds and they seem to work great... they look really trick too because they turn like blue/green/maroon colors.

 

Headers that are "wrapped" do not corrode because moisture is held in the wrapping. They corrode because the steel tubing reaches 1,500+degF, the same as the exhaust gas temp at WOT. Simple carbon steel is not intended fo function at those temperatures. Heat it that hot, and the outside of the tube starts to "rust" because the excessively high tube metal temperature is enough to cause the iron in the tube to combine with oxygen in the atmosphere = "rust". And, after being heated to those high temperatures, the chemical composition of the steel changes, and they become "brittle".... the constant heat cycling and vibration causes them to strart cracking.

Cerametallic coatings avoid these problems, by using a coating on the inner side of the tube to reflect heat back into the exhaust gasses.... as noted in a post above, providing more velocity and scavenging in the tubes. Reflecting the heat with the inner coating - something you will never accomplish with "paint" - is what reduces corrosion, reduces stress cracking, and reduces heat loss to the engine compartment. The outer coating helps too, but it is the inner coating that provides a large benefit.