It just keeps rolling along.....
Via PM'*, but I thought it would be nice to capture it here:
Originally Posted by somebody
and by the way theres another easy way to turn your supercharger black without paint. Aluminum i found will anodize black in a 30/70 mix of amonia and water heated up to a boiling point will cauce the aluminum to turn dark grey to black all you have to do is polish it if you desire a shiny surface.
You didn't read it. You don't WANT a polished surface. You want rough or textured for better heat transfer. The color has VERY little to do with it. It'* all about surface area.
Thermal conductivity and heat transfer in this case are enhanced by increasing the surface area through inducing irregularities with the coating. In the same way the fins/ribs over the supercharger do, on a smaller scale, but over the entire surface. The Black Body theory may be partially responsible for the increased thermal transfer rate that I proved, but the textured finish is the primary cause of the result.
This isn't your garden-variety textured paint, either. It'* a formulation that should withstand everything I throw at it under the hood.