S&S CYCLE 129" Power Package Engine Performance Kit for M8 – Chain Drive, Oil Cooled, Highlighted Fins – Part 310-1225

S&S CYCLE

S&S CYCLE 129" Power Package Engine Performance Kit for M8 – Chain Drive, Oil Cooled, Highlighted Fins – Part 310-1225

Product type: Big Bore Kits

Vendor: S&S CYCLE

SKU : 0904-0101

Regular price $3,359.95 USD

Lease to own Pay as low as $/week

Get Pre-approved

129" Power Package Engine Performance Kit - Chain Drive - Oil Cooled - Highlighted Fins - M8 Upgrade your Harley-Davidson M8 engine...

Lease for as low as $/week Apply Now

QUESTIONS & ANSWERS

Have a Question?

Be the first to ask a question about this.

Ask a Question

Category:

Details

129" Power Package Engine Performance Kit - Chain Drive - Oil Cooled - Highlighted Fins - M8

Upgrade your Harley-Davidson M8 engine with the S&S CYCLE 129" Power Package Engine Performance Kit, designed for seamless installation without case machining. This high-performance kit transforms a 107" oil-cooled M8 engine into a powerful 129" setup, offering increased displacement and torque for enhanced riding experience. The kit includes big bore cylinders that come with a matching cam, cam plate, and oil pump, ensuring optimal compatibility and reliable performance. The independent scavenge sections for the flywheel cavity and cam chest help maintain proper oil circulation, while a magnet in the cam chest assists in debris prevention to protect your engine components. Featuring high-performance conical single-wire S&S valve springs, this kit is engineered for durability and consistent valve operation under demanding conditions. Original engine serial numbers are retained, ensuring compliance with warranty and registration requirements. Passage plugs are removable for straightforward servicing, and debris screens in both scavenge pickups help keep oil passages clear, reducing maintenance needs. The MLS (multi-layered steel) head gaskets provide a robust seal to handle increased pressure, and the performance-matched 550 cam enhances power delivery across the RPM range. Compatible with stock crankcases, this kit offers a straightforward upgrade path for Harley enthusiasts seeking increased performance. Proudly made in the USA, the S&S CYCLE 129" Power Package Kit delivers reliable, high-quality performance enhancements for your M8 engine, combining proven design, innovative features, and durable construction to meet the demands of serious riders.

Features: