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Upgrade your Harley-Davidson M8 engine with the S&S Cycle 129" Power Pack, designed for exceptional performance and reliable operation. This bolt-on big-bore kit increases engine displacement from 107 inches to 129 inches without requiring case machining, making installation straightforward for experienced mechanics and enthusiasts alike. The kit features 4.32-inch bore cylinders with a high compression ratio of 11.0:1, paired with forged pistons that deliver increased power and durability for demanding riding conditions.
The engine components include an S&S oil pump and cam plate with a sleek blue anodized finish, enhancing both aesthetics and functionality. Passage plugs are removable for easy servicing, while independent scavenge sections for the flywheel cavity and cam chest ensure efficient oil flow and cooling. A debris screen in both scavenge pickups and a magnet in the cam chest help prevent debris from entering the oil pump, prolonging engine life. The oil flow capacity has been increased on both feed and scavenge sides, ensuring optimal lubrication during high-performance operation.
The kit includes an adjustable pressure relief valve, allowing fine-tuning of oil pressure with the unit installed in the engine. Quickee pushrods and S&S premium tappets facilitate precise valvetrain operation, while hard-anodized, black-coated tappet cuffs made from billet aluminum add durability and style. S&S 550 cams are specifically designed for big bore applications, offering increased lift and performance potential, compatible with valve springs up to 0.605 inches lift. The high-performance conical single wire springs are engineered for durability and consistent operation under high stress. All necessary gaskets, bearings, and hardware are included for a seamless bolt-on installation.
Crafted in the USA, this power pack is built for serious riders seeking increased horsepower and torque. Please note, this kit is not compatible with any Trike models, ensuring proper fitment for standard Harley-Davidson touring motorcycles. Enhance your engine’s capabilities with the S&S Cycle 129" Power Pack and enjoy improved acceleration, handling, and overall performance on the road.
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