1200cc Piston Set .040 Oversize(SET)

Keith Black flat top piston set is 040 oversize with a 891 compression ratio for 1988up XL 1200cc Evolution modelsbrbrThe Keith Black 390 hypereutectic alloy is cast in a permanent steel mold which makes it possible to build a light weight piston that makes more power and uses less fuel and lasts longer Pistons are 040 oversize for a 3498 bore and has a 91 compression ratio The low heat transfer of the alloy keeps the skirts cool so piston expansion is minimal The combination of a low heat transfer piston alloy and high compression ring placement increases power and economy The high ring placement alone reduces detoantion and increases the top ring temperature NoteRun engine at moderate speeds for at least 500 miles avoiding excessive running in lower gears in order to properly breakin new pistons and rings