[Bummo]

I cant remember which actually reduces engine temp, headers or stock exhaust manifolds. I think headers add to underhood temperatures, but if you are piping in fresh air for the intake that wouldn't matter too much. Is this added heat in the engine compartment coming off the header tubes not the same heat that the exhaust maniflods keep in the head and manifold combination? So if I want to reduce engine temp then headers should be better? Right?

 

[Guest]

The way I understand it, manifolds, because of their design, transmit a portion of their heat to the coolant via the heads. Headers, because of their length and the materials used, have more radiant heat with very little of that passed into the coolant. Headers create more underhood heat if left uncoated. The new coatings like ceramic and nickel may help to reduce that heat though.

 

[Evildriver-3]

Yeah you and PG got it

 

[m2bueller]

Headers and header wrap would be the best of all solutions.