S&S Cycle 129-Inch Power Package for M8 Engines - Part No. 310-1397

129" Power Package - HPT496 - Gear Drive - Oil Cooled - Black w/o Highlights - 107" M8

Upgrade your Milwaukee 8 (M8) engine with the S&S Cycle 129-inch Power Package, part number 310-1397. This comprehensive big bore bolt-on kit increases engine displacement from 107 inches to 129 inches without requiring case machining, making it an ideal choice for enhancing performance and power output. The kit features a high-performance 4.320-inch bore cylinder and 11.0:1 forged pistons, delivering increased compression for better torque and acceleration. Incorporating an S&S oil pump and cam plate, the setup ensures reliable oil flow and efficient lubrication under demanding riding conditions. Passage plugs are removable for maintenance, and independent scavenge sections for the flywheel cavity and cam chest include debris screens, helping prevent contaminants from entering critical oil passages. A magnet in the cam chest further protects the oil pump from debris buildup, promoting engine longevity and smoother operation.

Features:

• Big bore bolt-on kit increases engine displacement from 107" to 129" without case machining

• Includes a 4.320" high-performance cylinder with 11.0:1 forged pistons for increased power

• S&S oil pump and cam plate for improved lubrication and oil flow

• Removable passage plugs facilitate servicing and maintenance

• Independent scavenge sections with debris screens for cleanliness and reliability

• Magnet in cam chest to help prevent debris from entering the oil pump

• Enhanced oil flow capacity on both feed and scavenge sides for better cooling

• Adjustable pressure relief valve for tuning oil pressure with the engine installed

• Quickee pushrods with pushrod tubes and premium S&S tappets for precise valve operation

• Black coated, billet aluminum tappet cuffs for durability

• S&S valve springs compatible with cams up to 0.605" lift and dual generation valve ports

• HPT496 cam designed specifically for big bore applications to maximize performance

• MLS (multi-layered steel) head gasket for a reliable seal and durability

• Includes a 129 cam cover badge for a finished look

• Engine retains stock height and works seamlessly with stock crankcases and roller rocker arms

• Original engine serial numbers are preserved for registration and warranty purposes

• Made in the USA, ensuring quality craftsmanship and standards