Select type, year, make, and model
Upgrade your Harley-Davidson M8 engine with the S&S CYCLE 129" Power Package Engine Performance Kit, part number 310-1223. Designed for seamless installation, this kit transforms your 107-inch oil-cooled M8 into a powerful 129-inch engine without the need for case machining. It features big bore cylinders that come complete with a matching cam, cam plate, and oil pump, ensuring optimal performance and compatibility. The kit's independent scavenge sections for the flywheel cavity and cam chest help maintain oil flow efficiency, while a magnet in the cam chest aids in debris prevention to protect your oil pump.
High-performance conical single-wire S&S valve springs are included to enhance valve stability at higher RPMs. The design retains the original engine serial numbers for authenticity and compliance. Passage plugs are removable for convenient servicing, and debris screens are integrated into both scavenge pickups to prevent contaminants from entering vital engine components. The MLS (multi-layered steel) head gaskets provide reliable sealing under high-pressure conditions, contributing to engine longevity. The performance-matched 550 cam offers increased horsepower and torque, delivering a significant upgrade over stock components. This engine kit is compatible with the stock crankcase, making installation straightforward for experienced builders. Made in the USA, the S&S CYCLE 129" Power Package Engine Performance Kit is a trusted choice for motorcycle enthusiasts seeking reliable, high-performance upgrades to their M8 engine.
Features:
US Dollars
