Bare Naked Radiator

[MikeAH100M]

At a recent British Car Show, I noticed several 3000's with unpainted radiators. I just had my BN2 radiator cleaned and stripped and like the look of the bare brass and copper. I know its not spec but am wondering if the bare radiators were done to increase heat transfer and not just for looks. Any thoughts on leaving the radiator unpainted?

 

[Randy Forbes]

I don't know, but I like the look too. It is true, the paint will act as an insulator, reducing heat transfer.

I stripped the Spridget overflow tank too

 

[Chris_Masucci]

I don't know if bare will actually transfer heat energy any better. Speaking from a Physics background, what I can say is that the closer you get to a black body model, the faster you can both absorb and radiate thermal energy. So theoretically, flat black paint that is thermally conductive would be the best.

 

[Patrick67BJ8]

I don't know if bare will actually transfer heat energy any better. Speaking from a Physics background, what I can say is that the closer you get to a black body model, the faster you can both absorb and radiate thermal energy. So theoretically, flat black paint that is thermally conductive would be the best.

Questions about "bare radiators" vesus painted ones came up several years ago. I did some research on it by asking the "professionals" and the "special radiator paint" does work better for cooling than a "bare" radiator.

 

[Hawkscoach]

the previous car I restored was a 69 SS396 Camaro. Due to the big block, etc. it was recommended to me to use a special black paint to transfer the heat and protect the surface, which I used and have had no problems. I purchased the paint from "Ricks Camaro" which is now owned by "Ecklers" I believe. Hope this helps, Doug

 

[CLEAH]

All paint does on a radiator is protect the metal (and for aesthetics). Painting metal, though, creates a slight insulative barrier that will impede heat transfer. And the color does not matter. In a darkened engine compartment, what does heat care if the outside coating is black or white or blue as it travels from inside the radiator to the outside? I just spoke with an HVAC engineer and he indicated that manufacturers never paint coils unless for protection because paint insulates. Ever see a modern racing car with a painted radiator? No, they are bare aluminum.

Go ahead and keep the nice shiny copper top on your radiator!

 

[Randy Forbes]

I apply a polymer coating (metallic-ceramic compound) that is billed as a thermal dispersant on many internal and external engine parts, but I wouldn't call it paint, per se.

There were numerous application opportunities for thermal dispersant, as well as thermal barrier and dry-film lubricant polymer coatings on this BMW S-54 nM3 engine build: