KB Performance, 1200cc B.T. forged piston kit. +.020"

41-78 1200cc/80" Kncukle, Pan, Shovel (NU)

Forged piston set. 8.5:1 CR with 112cc head. Standard replacement. Piston weight 456gr. Piston pin weight 97gr. Piston pin dia. .791" / offset. Head type: Dome with -47.6cc. Compression height 1.450". Bore 3.437". Stroke 3.969". Rod length 7.440". Cyl. length 5.330". All KB forged pistons are made from 4032 alloy, a 11% silicon alloy that is formed in a forging press. Forging aluminum gives a superior strength and structural integrity on a molecular level, after which it is fully machined. The combination of this alloy and the forging process allows the piston to flex under detonation, or pre-ignition, giving the best resistance to cracking. Although 4032 has a low expansion rate, it is higher than the cast Hypereutectic. Therefore forged KB pistons will require about .001" wider piston to wall clearance. Pistons are sold as sets, complete with wrist pin retaining rings, wrist pins and piston rings. Please note that all KB forged pistons come equipped with offset wrist pins / piston pins. There is a front and rear section on the piston and it is necessary to install it in the correct way. Please refer to the installation instructions, as provided with each piston set, prior to installation.