(I did a search with no luck, so bare with me please)

I thought I read somewhere in here that polishing an engine block retains heat.

Just out of curiousity, would polishing an exhaust pipe (header?) accomplish the same thing?

Is there any reason why I wouldn't want to keep the heat trapped within my exhaust pipe so it can exit out of the muffler?

 

Instead of trying to keep it polished, just use a header wrap. I ordered the wrap for my truck from summit racing, but you should be able to find at any speed shop.

The only reason I wrap mine is to keep the heat out of the engine bay. This reduces the overall temp and the intake air temp. I don't know if you will see any gains. I have heard that the thinner a 2-stroke pipe is, the more power it makes due to release of heat.

 

POWDER COAT IT!!

 

I heard ceramic coated cylinder and head add alot of power and keep the heat down. go to www.lukesracing.com

 

Polishing the engine will not trap the heat, it would not affect the temp at all. Polishing the head pipe will not affect its temp either. If you paint or powder coat the engine it could, in theory cause the engine to run hotter, but I don't think by much.
Now the header is another story, having it ceramic coated will increase its performance. Jet hot works. The high temp powdercoatings will stick to the pipe but don't affect the performance.