VT#: 11-2267

Keith Black piston set is .020 oversize and is for a 3-3/4" bore. Piston set has a compression ratio of 8.8:1 and includes rings. The 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 .020 oversize, for a 3-3/4" bore and has a 9.25:1 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 detonation and increases the top ring temperature.
**NOTE:Run engine at moderate speeds for at least 500 miles, avoiding excessive running in lower gears, in order to properly break-in new pistons and rings.

FXST Softail® 1999-2006
FLST Heritage Softail® 1999-2006
FXD Dyna Glide® 1999-2006
FLT Tour Glide® 1999-2006