After running extremely rich for the past 10k miles (bad tune), I pulled off my head tonight so I could swap on a stock head and pass smog.

As expected, there were extreme amounts of carbon buildup on my CP pistons. I cleaned the piston tops using all sorts of different methods, but the final pass was done with 2000 grit sandpaper. This left the pistons with a very hazy, swirled look instead of the factory polish.

So now I'm wondering - are polished tops even beneficial? I've done some searching around online, and most places (that manufacture polished pistons) claimed that polished tops lowered combustion temps, "even after the pistons became covered in black carbon."

Sounds like bullshit to me. How can a polished dome matter at all if it's covered with carbon?

Any input is welcome, expecially input that verifies how useless polished domes are because it will make me feel better about ruining the finish on mine

 

from my past younger years of messing with v-8's and what not i learned that its good to scuff the piston tops. mainly the sharp edges (valve reliefs, dome peaks)
i usually go with a scotch bright pad and scuff the tops. it helps prevent a sharp edge from turning into hot spots that can lead to preigintion.. i see alot of people put new pistons in all shiny and all but its not in how it looks its how it works.. my 2 cents says that polished pistons are not good but hazy/scuffed ones are..