S&S CYCLE Power Pack - Oil Cooled - M8 310-1103B

If you're serious about maximizing displacement and power output on your M8, the S&S Cycle Power Pack delivers measurable gains without requiring case machining—meaning you can install it as a bolt-on upgrade. This big bore kit combines forged pistons, precision-machined billet components, and engineered oil management to ensure reliability at sustained high RPM, whether you're tracking your bike or pushing it hard on the street.

The heart of this kit is an oversized 4.250" bore that increases swept volume, paired with an 11.1:1 compression ratio tuned for forced induction applications. Every component, from the billet aluminum oil pump to the premium tappets and quickee pushrods, is engineered to work together—eliminating weak points and delivering consistent performance gains.

• 4.250" bore diameter
• Forged pistons included
• 11.1:1 compression ratio
• Bolt-on installation
• No case machining required
• Billet aluminum oil pump
• Independent scavenge sections
• Adjustable pressure relief valve
• Debris screening both pickups
• Cam chest magnet included
• S&S 550 cam included
• Premium S&S tappets
• Billet tappet cuffs
• Quickee pushrods included
• Increased flow capacity
• MPN: 310-1103B