S&S Cycle Big Bore Kit - 4.25" Bore - 128ci - Black - 310-1106C

Unleash the ultimate performance from your Harley-Davidson Milwaukee-Eight engine with the S&S Cycle 128" Power Package Big Bore Kit. Engineered for enthusiasts seeking a significant boost in power and torque, this comprehensive kit transforms your 114" or 117" M8 into a formidable 128" beast, ready to dominate the open road.

Description

The S&S Cycle 128" big bore kit is a meticulously designed performance upgrade that delivers an impressive increase in engine displacement and horsepower. This bolt-in big bore kit simplifies installation by eliminating the need for complex case machining, making it an accessible yet powerful modification for your motorcycle. At its heart are robust forged pistons, built for extreme durability and optimal performance under demanding conditions. The kit’s 11.1:1 compression ratio is perfectly matched to the S&S 550 camshaft, ensuring a broader powerband and crisp throttle response.

This comprehensive motorcycle power package includes everything needed for a complete engine overhaul, featuring a high-flow S&S oil pump and cam plate, Quickee pushrods with sleek chrome covers, heavy-duty tappets, and tappet cuffs, alongside upgraded valve springs. Each component is engineered to work in harmony, providing a reliable and exhilarating ride. Whether you're looking to improve acceleration, increase top-end power, or simply experience a more responsive engine, the S&S Cycle performance engine kit delivers the quality and performance expected from a leader in the motorcycle industry.

Features & Highlights

• Massive Displacement Upgrade: Transform your 114" or 117" Milwaukee-Eight engine into a formidable 128" powerhouse, delivering a substantial increase in displacement and raw power for an exhilarating ride.
• Effortless Bolt-In Installation: Designed for a straightforward upgrade, this premium kit requires no complex case machining, making installation quicker and more accessible for enthusiasts and professionals alike.
• Unmatched Durability with Forged Pistons: Experience superior engine reliability and longevity, thanks to the included high-strength forged pistons engineered to withstand the rigors of increased power and aggressive riding.
• Optimized Camshaft Performance: Featuring the renowned S&S 550 camshaft, this package ensures optimized valve timing for a broader powerband and aggressive throttle response, enhancing your motorcycle's overall performance.
• Comprehensive Engine Component Kit: Beyond the big bore cylinders, the kit provides essential components including an S&S oil pump/cam plate, Quickee pushrods with stylish chrome covers, heavy-duty tappets, tappet cuffs, and robust valve springs for a complete, integrated power solution.

Technical Specifications

• Model: Power Package
• Units: Kit
• Bore Size: 4.250"
• Color/Finish: Black, Non-Highlighted Fins
• Displacement: 128"
• Stroke Length: 4.500"
• Cam Drive Type: Gear
• Cooling System: Oil Cooled
• Compression Ratio: 11.1:1
• Vendor Part Number: 310-1106C

Important to Know

• Not for 121" CVO models.
• Not for any Trike models.
• Intake/rocker cover gaskets not included.