S&S Cycle 129" Power Package Engine Kit for M8

Transform your 107" Milwaukee-Eight engine into a formidable 129" powerhouse with the S&S Cycle 129" Big Bore Kit. This comprehensive bolt-on performance package is engineered to deliver a significant boost in displacement and raw power, all without the need for complicated case machining.

Description

This S&S Cycle 129" Big Bore Kit is meticulously designed to elevate the performance of your Harley-Davidson M8 engine. Featuring robust 4.32" bore cylinders and high-performance 11.0:1 compression ratio forged pistons, this kit ensures a dramatic increase in displacement from 107" to a staggering 129". The true advantage lies in its bolt-on design, eliminating the need for complex and costly case machining, making it an accessible upgrade for serious riders.

Beyond just displacement, the kit includes an advanced S&S oil pump and cam plate, boasting a sleek blue anodized finish. This system is engineered for superior lubrication, featuring independent scavenge sections for both the flywheel cavity and cam chest, ensuring optimal oil return and reduced oil starvation. Debris screens in both scavenge pickups, along with a magnet in the cam chest, provide crucial protection against harmful contaminants entering the oil pump. Increased oil flow capacity on both the feed and scavenge sides, coupled with an adjustable pressure relief valve, guarantees consistent oil pressure and engine longevity.

Further enhancing performance are the S&S 550 cams, specifically designed for big bore applications, paired with Quickee pushrods and S&S premium tappets. The billet aluminum, hard-anodized, black-coated tappet cuffs provide exceptional durability. High-performance conical single wire valve springs are included, capable of handling cams with up to 0.605" lift, ensuring reliable valve train operation even under extreme conditions. Every component in this M8 engine upgrade reflects S&S Cycle's commitment to quality and performance, promising a durable and exhilarating riding experience. All necessary gaskets, bearings, and hardware are included for a straightforward bolt-on installation, making your transition to a more powerful engine seamless. Proudly Made in the USA, this performance kit is a testament to American engineering excellence.

Features & Highlights

• Massive Displacement Increase: Transforms your 107" M8 engine to a powerful 129" with 4.32" bore cylinders and 11.0:1 compression forged pistons, delivering a significant boost in torque and horsepower.
• Effortless Bolt-On Installation: Designed for direct fitment without requiring any costly or time-consuming case machining, simplifying your upgrade process.
• Advanced S&S Oil System: Includes a blue anodized S&S oil pump/cam plate with independent scavenge sections, debris screens, and a cam chest magnet for superior lubrication, filtration, and engine protection.
• Optimized Valvetrain Components: Features S&S 550 cams for big bore applications, Quickee pushrods, premium tappets, and billet aluminum tappet cuffs, ensuring robust and reliable valve train operation.
• High-Performance Valve Springs: Conical single wire spring design supports cams up to 0.605" lift, providing excellent stability and performance for aggressive cam profiles.
• Complete Installation Kit: Comes with all necessary gaskets, bearings, and hardware for a comprehensive and hassle-free bolt-on installation.
• Proudly Made in the USA: Engineered and manufactured in the United States, ensuring top-tier quality and craftsmanship.

Technical Specifications

• Product Name: Performance Kit
• Type: Engine
• Model: Power Package
• Units: Kit
• Displacement: 129" (4.32" Bore x 4-3/8" Stroke)
• Compression Ratio: 11.0:1
• Cooling System: Oil Cooled
• Cam Drive Type: Gear
• Color/Finish: Non-Highlighted Fins, Wrinkle Black
• Features: Black Pushrod Tubes
• Vendor Part Number: 310-1228C

Important to Know

• Compatibility Restriction: Not for use with any Trike models.