Well I do not know what you are trying to do...
But if you want heat to stay away from something, do not wrap it in a conductor like aluminum foil.
Have you looked at header wrap?
When I need to replace my air filter I'm going to buy the CTA intake and wrap it in this stuff to keep heat out of the aluminum pipe which could theoretically heat up the air coming in (never know, won't hurt to do it)...
