1200cc Piston Set.040 Oversize - Keith Black KB295 .040 - Evolution Sportster 1988+
Keith Black #: KB295 .040
Keith Black flat top piston set is.040 oversize with a 8.9:1 compression ratio for 1988-up XL 1200cc Evolution models.
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.040 oversize for a 3.498 inch bore and has a 9:1 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.
Fitment:
| 1988-UP | XL |