S&S Cycle M8 Big Bore Kit - 4.25" Bore - 128ci - 310-1107C

Unlock the full potential of your Harley-Davidson engine with the S&S Cycle 128" Big Bore Kit. Engineered to transform your 114" or 117" CVO model, this premium performance kit delivers a significant engine upgrade to 128 cubic inches, providing a dramatic boost in horsepower and torque for an exhilarating ride.

Description

Experience unparalleled power and a noticeable performance improvement with this comprehensive S&S Cycle 128" Big Bore Kit. Designed for a straightforward installation, this bolt-in kit eliminates the need for complex case machining, making your engine upgrade process smoother and more efficient. At its core are high-strength forged pistons, meticulously crafted to withstand the demands of increased power and ensure long-lasting durability. The kit boasts an aggressive 11.1:1 compression ratio, optimized for maximum energy conversion and thrilling acceleration across the RPM range. With a precise bore size of 4.250" and a stroke length of 4.500", this performance package is engineered for optimal volumetric efficiency. Beyond raw power, the kit includes a sophisticated S&S 550 camshaft, an upgraded oil pump/cam plate, Quickee Pushrods with stylish chrome covers, high-quality tappets, and tappet cuffs, alongside robust valve springs. These components work in harmony to create a reliable and high-performing water-cooled system. Finished in an attractive Black Granite with highlighted fins, this kit not only enhances your motorcycle's performance but also its aesthetic appeal, contributing to better heat dissipation.

Features & Highlights

• Effortless Bolt-In Installation: Transform your engine without complex case machining, making this a straightforward upgrade for 114" and 117" CVO models.
• Massive 128 Cubic Inch Upgrade: Elevate your engine's displacement to a potent 128 cubic inches, delivering a substantial increase in horsepower and torque for thrilling acceleration.
• Premium Forged Piston Construction: Engineered with robust forged pistons, ensuring exceptional durability and reliability even under extreme performance demands.
• Integrated Performance Components: This comprehensive package includes an optimized oil pump/cam plate, S&S 550 camshaft, valve springs, Quickee Pushrods with Chrome Covers, and upgraded tappets/cuffs for a fully harmonized system.
• High 11.1:1 Compression Ratio: Experience aggressive throttle response and enhanced power output thanks to the optimized compression, designed for peak performance.
• Enhanced Aesthetics & Thermal Management: Featuring a sleek Black Granite finish with highlighted fins, this kit not only looks exceptional but also aids in efficient cooling for sustained performance.

Technical Specifications

• Model: Power Package
• Units: Kit
• Bore Size: 4.250"
• Color/Finish: Black Granite, Highlighted Fins
• Displacement: 128 cubic inches
• Product Name: Performance Kit
• Stroke Length: 4.500"
• Cam Drive Type: Chain
• Cooling System: Water Cooled
• Compression Ratio: 11.1:1
• Vendor Part Number: 310-1107C

Important to Know

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