Description
Building serious displacement on your Big Twin? The S&S CYCLE Piston Kit 920-0015 delivers a straightforward path to 1250cc without sacrificing reliability. By stepping up from stock bore dimensions, you gain meaningful low-end torque and mid-range power while maintaining the 10.3:1 compression ratio that works with both stock and performance heads.
Whether you’re running a classic 883cc or pushing a 1200cc platform, this cast flat-topped design has been proven in the field since 1984. Installation is straightforward on compatible big-block cases, and the geometry plays well with stock cylinder heads—though pairing these pistons with S&S CNC ported heads unlocks their full potential.
- Displacement: 1250cc
- Compression ratio: 10.3:1
- Bore diameter: 3-9/16″
- Piston type: Cast flat-topped
- Compatibility: 1984–’99 HD Big Twins
- Works with: Stock heads or S&S performance heads
- Requires boring: 1200cc and 1986–’03 883cc cylinders
- Not compatible: 2004–’16 883cc cylinders
- Installation: Bolt-on (on prepared cylinders)
- MPN: 920-0015
