One for all you derv lovers.

[Grant]

Eh? Got plenty to worry about, just annoyed muppets like this are able to build a career on mis-educating people, which i guess is what you're alluding to as a petty concern..?

Now; I've not conducted the above experiment, nor do I have any intention to do so. I have more important things to do such as read this forum and look at boobs on the internet. However:

On the surface of it; heat is radiated in the form of infrared radiation. Yes, an unpainted surface would be better for conducting heat from one surface, to another, however, a fully heat-soaked, painted intercooler, radiating heat (where the paint is already at a said temperature), in my opinion, would disperse the infrared radiation at a quicker rate due to the greater absorptive properties of a darker surface.

Ofcourse, i have no proof to support the above, so shy of us going down the pub to battle it out, I guess we will never know :p