Coatings for flats

No experience - just interest....I'll be waiting to see what replies come in.
BTW, do you apply the teflon yourself? How?

No experience, but intend to follow the same plan - keep the BTUs in the chamber as much as possible.

I have a friend that runs an industrial coatings place. He has been applying these coatings for years. we did teflon on the skirt and ceramic on the dome of the pistons in my stroker shovel and it was a bitch to tune as the pistons did not realize they're full expansion and seal untill 15 or so miles. It looks to me as if there almost has to be a hot spot/cyl distortion in a side valve engine. I could not figure out a way to simulate it to find out because of varying combustion temps and residual exhaust heat that occur at different speeds. Hopefuly I'm not spinning my wheels.

Rene, I'm coating the inside of the exhaust port as well, the only place that will be metal to metal will be the seating faces. This should keep the cylinder casting from absorbing the combustion temps. I'm also hoping for a better head and base gasket seal. If the temps are held down, the expansion rates should be more even and slow down the gasket scrub.

I hope you're keeping notes and taking pictures, This is unknown territory for us dinosaurs!

Well Cotton I hope it works, I talked to the owner of the bike yesterday and he agreed to let me keep it around and put the first few hundred miles on it, so I may have an opportunity to document the temps Etc. I have another question, have you ever used cold galvanizing compound (spray can) for gasket sealer on head gaskets? I used it on shovels for a while when we couldn't get good gaskets. I had to tear one back down to put a little extra valve clearance in it and almost never got the head off. I truly believe this engine would have run without headbolts. I put a hammer handle in the front exhaust, a cheater pipe over that, and was picking the front tire off the ground and shaking it while someone else hit a 2x4 with a three lb shop hammer. It split the gasket. After cleaning that mess up, I didn't use it any more, but it may be a cure for someone with high cyl pressures.

Yah, the 1937-48 U cylinders had the front exhaust port angled away from the best location. It ducks back to the left to fit bwteen the tubes of that new-fangled OHV frame. Maybe Anders can cast some with the port in the right location??
Yes, I think shortening the port and cutting away as much material as possible to prevent heat soak back into the parent casting was the direction Branch was going on the KR.