Ok so pulled my finned drums today and plan on cleaning them up,,I thought about polishing them,but was told that's not the best idea ,as when you polish something linke that it becomes less porous and does not disperce heat as well.Anyone vere heard of this??
I've polished the smaller GM finned drums in my vibratory finisher and they look nice, if not as shiny as a traditional buffer type job. Unfortunately the Buicks are too big for my tub. I can't see any downside to polishing an aluminum drum. A) The drum is aluminum. Aluminum conducts heat about four times better than steel/iron. B) It has a lot of fins for surface area. Road grime will fill in the pores anyway in use, why not just get rid of them to start with.
If there is any amount of truth to the heat dissipation idea, it certainly won't make a difference on a street-driven car. Polish them.
A smoother surface will have a smaller amount of surface area, and as a result a lower heat transfer capability. However, in a real application like this it's not going to really matter. Think of the surface roughness as a bunch of tiny fins. But in this application, I doubt you could measure a difference between a highly polished drum and a normal one. If you really want to help it ditch heat, anodize it flat black
I've had several cars with polished Buick drums and several with just sandblasted drums and never noticed any difference.
Polishing won't hurt and will work just fine. They really look great that way. If you want to do it the easy way, send them out to be Jet-Hot coated and you will never have to repolish them again. Ask for the same color they use on headers, brite chrome. I did a set and they look great.
Black doesn't retain heat, it just that when it's on a surface, it absorbs more radiation from outside sources which gets converted to heat.
Yes,polishing them slows heat dissapation,but probably not enough to worry about in a light car.Jet hot coating them also would retain heat,just like lt keeps the heat "inside" headers.
radiator manufacturers will tell you for best heat dissapation DO NOT paint your radiator they reccommend just spraying them from time to time with something like PB Blaster or some other fine penatrating oil
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