Lightweight Engine Components

Honda Motorcycle had an experimental motor that had ceramic pistons that were not round but shaped like a 3bbl secondary. Larger bore size with a smaller cylinder, less friction and heat loss or something like that. Rings would be a nightmare unless they were a 2 part that lapped in he middle? google GTP race Polymotor. Ceramics are F'n hard as hell to machine. Diamond bits are about the only thing that works.