S&s Cycle 128" Big Bore Power Package Kit

Unleash the full potential of your motorcycle engine with the S&s Cycle 128" Big Bore Power Package. This comprehensive kit delivers a significant boost in displacement and performance, featuring high-quality forged pistons, a performance camshaft, and an advanced oil pump system designed for a true bolt-in upgrade.

Description

The S&s Cycle 128" Big Bore Power Package is an expertly engineered motorcycle engine upgrade designed to deliver unparalleled power and reliability. With an impressive 128" displacement, achieved through a 4.250" bore and 4.500" stroke, this kit dramatically increases your engine's output. The heart of this system includes durable forged pistons and an updated profile, ensuring robust performance and longevity even under extreme conditions. Boasting a commanding 11.1:1 compression ratio, you'll experience a noticeable surge in acceleration and torque.

This comprehensive performance kit features a precision-machined billet aluminum oil pump/cam plate, engineered for superior oil management. It includes independent scavenge sections for both the flywheel cavity and camchest, debris screens in both scavenge pickups, and a magnet in the camchest to prevent harmful debris from entering the pump. With increased oil flow capacity on both the feed and scavenge sides, and a pressure relief valve that's adjustable while installed, your engine's lubrication is optimized. The kit also integrates S&s Cycle's renowned 550 camshaft, paired with Quickee pushrods and premium tappets featuring hard-anodized, billet aluminum, black-coated tappet cuffs for exceptional stability in high-lift and high-RPM situations. Valve springs are included, designed to work seamlessly with camshafts up to 0.605" lift, complete with top collars, keepers, valve seals, and bottom collars. Proudly made in the USA, this power package is a true bolt-in solution, requiring no case machining and compatible with VVT models, making it an accessible yet powerful engine upgrade.

Features & Highlights

• Experience a significant power boost with the bolt-in 128" displacement and 11.1:1 compression ratio, featuring an updated profile and durable forged pistons for superior performance.
• Enhance engine longevity and lubrication with the precision-machined billet aluminum oil pump/cam plate, offering independent scavenge sections, debris screens, and a camchest magnet for optimal oil management.
• Optimize valvetrain stability and performance with S&s Cycle's 550 camshaft, Quickee pushrods, and premium tappets featuring hard-anodized billet aluminum cuffs, designed for high lift and RPM scenarios.
• Ensure robust valve control with included valve springs, top collars, keepers, valve seals, and bottom collars, compatible with camshafts up to 0.605" lift.
• Enjoy hassle-free installation with a true bolt-in design that requires no case machining, compatible with VVT models.
• Proudly made in the USA, ensuring exceptional quality, reliability, and precision engineering.

Technical Specifications

• Model: Performance Kit
• Style: 550G
• Bore Size: 4.250"
• Color/Finish: Highlighted Fins, Black Granite
• Displacement: 128"
• Stroke Length: 4.500"
• Cam Drive Type: Gear
• Cooling System: Oil Cooled
• Compression Ratio: 11.1:1
• S&s Cycle Part Number: 310-1110D

Important to Know

• Not for any Trike models.
• Intake/rocker cover gaskets are not included.