High compression pop-up piston set. 9.5:1 CR. Piston weight 388gr. Piston pin weight 97gr. Head type: Dome / Dome -47cc. Compression height 1.285" / Bore 3.4980". Stroke 4.250". Rod length 7.440" / Cyl. length 5.330". Comes with T6 heat treated 390 Hypereutectic cast pistons with 16% silicone levels which enables running a very tight clearance for longevity and hardly any piston noise. Note: Top compression ring will need additional clearance. See instructions. Note: Around 30% of stock 1340cc Shovel cylinders may present a problem in combination with the location of some of the oil return holes since KB pistons have a wider piston ring pack for better piston stability in the cylinder. In these cases the oil return hole must be re-located (lowered) to avoid excessive oil consumption.
