Description
If you’re running a big bore M8 and want real gains in displacement and horsepower without dismantling your entire engine, the S&S CYCLE Power Pack delivers bolt-on simplicity with race-proven performance. This kit combines a 4.25″ bore with precision-engineered internals—forged pistons, an optimized cam, and a completely redesigned oil system—giving you the displacement increase you need while maintaining reliability under sustained high-RPM operation. Whether you’re on the dyno or the street, you get the displacement of a much larger engine rebuild without the downtime of case work.
Key Technical Specifications:
- Bolt-on installation
- 4.250″ bore diameter
- 11.1:1 compression ratio
- Forged piston construction
- No case machining required
- S&S 550 Cam included
- Billet aluminum oil pump/cam plate
- Increased flow capacity (feed + scavenge)
- Independent scavenge sections
- Debris screens on both pickups
- Magnetic cam chest protection
- Adjustable pressure relief valve
- S&S premium tappets
- Billet aluminum tappet cuffs
- Quickee pushrods
- Removable passage plugs
- Fits Harley-Davidson M8 engines
- MPN: 310-1104A
