S&s Cycle 129" Power Package Engine Performance Kit for 107" M8
S&s Cycle 129" Power Package Engine Performance Kit for 107" M8
About this product
About this product
Unleash the full potential of your Harley-Davidson Milwaukee-Eight engine with the S&S Cycle 129" Power Package Engine Performance Kit. This comprehensive bolt-on upgrade transforms your 107" M8 into a formidable 129" powerhouse, delivering significant gains in horsepower and torque without requiring any case machining.
Description
Engineered for motorcycle enthusiasts seeking a substantial performance boost, the S&S Cycle 129" Power Package Engine Kit provides everything needed for a dramatic displacement increase. At its core are big bore 4.320" cylinders paired with high-strength 11.0:1 forged pistons, meticulously designed for optimal combustion and durability. This kit includes the advanced S&S oil pump/cam plate, which features independent scavenge sections for both the flywheel cavity and cam chest, ensuring superior oil management. Integrated debris screens in both scavenge pickups and a magnet in the cam chest actively prevent contaminants from entering the oil pump, extending engine life. With increased oil flow capacity on both the feed and scavenge sides, and an adjustable pressure relief valve that can be serviced while installed, your engine's lubrication system is optimized for extreme conditions.
Further enhancing performance are the Quickee pushrods with black pushrod tubes, S&S premium tappets, and billet aluminum hard anodized, black coated tappet cuffs. The included S&S valve springs are high-performance conical single wire springs, designed to work seamlessly with cams up to 0.605" lift. The heart of this 129" M8 engine kit's aggressive power delivery is the HPT496 cam, specifically engineered for big bore applications. An MLS (multi-layered steel) head gasket ensures a robust seal. Proudly made in the USA, this kit retains your stock engine height, works with stock crankcases and roller rocker arms, and preserves original engine serial numbers, making it a professional-grade upgrade that fits like factory. It's also compatible with both first and second-generation stock valve springs.
Features & Highlights
- Transformative Big Bore Upgrade: Effortlessly convert your 107" Milwaukee-Eight engine to a potent 129" displacement with this bolt-on kit, eliminating the need for complex and costly case machining.
- Optimized Power & Durability: Features precision-engineered 4.320" big bore cylinders and robust 11.0:1 forged pistons, providing exceptional power gains and long-term reliability for your Harley-Davidson M8 big bore kit.
- Advanced Oil Management System: The S&S oil pump/cam plate boasts independent scavenge sections, debris screens, and a cam chest magnet, ensuring superior lubrication, contaminant removal, and increased oil flow capacity for peak engine health.
- Performance-Ready Valvetrain: Includes Quickee pushrods, S&S premium tappets with billet aluminum cuffs, and high-performance conical valve springs compatible with cams up to 0.605" lift for precise and durable valve control.
- Big Bore Specific HPT496 Cam: Experience aggressive power delivery and optimized performance thanks to the HPT496 cam, meticulously designed to complement the increased displacement of this 129" M8 engine kit.
- Seamless Integration & Quality: Made in the USA, this kit retains stock engine height, works with stock crankcases and roller rocker arms, and includes an MLS head gasket for a perfect fit and professional finish, complete with a 129 cam cover badge.
Technical Specifications
- Type: Engine Performance Kit
- Product Name: Power Package
- Style: HPT496 Series
- Units: Kit
- Bore Size: 4.320"
- Displacement: 129"
- Compression Ratio: 11.0:1
- Cam Drive Type: Chain
- Cooling System: Oil Cooled
- Color/Finish: Black, Highlighted Fins
- Features: Black Pushrod Tubes
- Vendor Part Number: 310-1395
Shipping & Return
Shipping & Return
Free shipping to GLS parcel shop parcel box for purchases over DKK 1,000.
GLS home delivery costs DKK 59.
We do our best to ship your order as quickly as possible. All orders are generally packed within 24 hours on weekdays.
There is a 14-day return policy. Read more
Specifications
310-1395
Black, Highlighted Fins
Performance Kit
Power Package
HPT496 Series
4,320"
11,0:1
129"
510 mm
305 mm
685 mm
Chain
Black Pushrod Tubes
Engine
Kit
Oil Cooled
Reviews


Who is behind Parts Denmark
Martin and William are the duo behind Parts Denmark — an unlikely but awesome combo of a tech-savvy young IT wizard and a seasoned motorcycle guru who’s seen (and fixed) it all. Together, we’ve built a team with big ambitions, plenty of passion, and a shared mission to create great things — side-by-side with you.
Based in Denmark
Fast customer support
Over 100.000 Products
2-Year Full Warranty
Your peace of mind is our priority. Every product in our shop comes with a comprehensive 2-year warranty, so you can hit the road with full confidence.
Support in Danish, Swedish, German & English
Whether you are upgrading your exhaust or choosing a new helmet, our team of seasoned riders is ready to provide professional guidance for your specific bike.
Free Shipping Over 200€ (EU)
Shop your favorite gear without worrying about extra costs. We offer free shipping on all orders over 200€ (EU), ensuring your parts reach you safely and affordably.
Authorized Parts Europe Dealer
As a certified Parts Europe supplier, we guarantee 100% authentic, high-quality motorcycle parts and accessories directly from the world's leading manufacturers.

