Originally Posted by
musti72
So, cleaning up this residue(brownish carbon) improves the performance of the engine? Sorry, I dont have a good English...
My engines perform exactly as you said. They run absolutely in top condition after breakin, but as the carbon builds up, they lose their "liveliness". But does cleaning up those residue brings the performance back, or makes it worse?
No, Absolutely not. You remove this build up on a piston and sleeve set running marginally, you will be increasings piston to sleeve bore clearance, making things worse. Again, I only clean these surfaces allowing me to match worn piston to newel y resized sleeve bore. Not to elaborate too much here, but this prepping procedure is one that simply allows me a clean surface to adjust ( reconstructing smaller bore a few tenths of one thousandth one inch) new fit to. It would be very the manufacturer to match piston + sleeve sets working with dirty surfaces. I hope this helps. RayAracing