Kb Pistons Hypereutectic Cast Piston 8.8:1 .020 - Harley Twin Cam 88ci
About Kb Pistons
KB Performance Pistons builds hypereutectic and forged pistons for American V-twin engines, and is a long-standing choice for big-bore and stock-replacement rebuilds where budget and durability both matter.
Unleash reliable performance from your Twin Cam 88ci with a Kb Pistons Hypereutectic Cast Piston. Engineered for air-cooled motors, this piston delivers a balanced 8.8:1 compression ratio and a .020 oversized bore for a refreshed top end. It's an ideal choice for riders looking to maintain a stock to mild tune while benefiting from enhanced piston integrity.
Why riders pick this
- 16% silicon hypereutectic alloy construction
- Resists thermal expansion for stable performance
- Maintains tight piston-to-cylinder clearances
- Reduces engine wear and promotes quieter running
- Optimized for stock to mild tunes on pump fuel
This Kb Pistons hypereutectic cast piston is designed for Twin Cam 88ci engines, offering an 8.8:1 compression ratio and a .020 oversized bore. Crafted from a specialized 16% silicon alloy, it's built to resist thermal expansion, which is critical for the demanding conditions of air-cooled Harley-Davidson motors. This allows for tighter piston-to-cylinder clearances, promoting quieter operation and reduced wear over time, making it a solid foundation for your build.
Engineered for Lasting Performance
- Hypereutectic alloy with 16% silicon content for superior heat resistance
- Low thermal expansion rate maintains tight piston-to-cylinder clearances
- Contributes to reduced engine wear and quieter operation
- Optimized for stock to mild tunes running on pump fuel
Building Your Top End
Whether you're refreshing an older engine or starting a new build, this piston provides a durable base. Its design is well-suited for stock or mild compression ratios, making it compatible with a range of cam profiles and exhaust systems without requiring extensive modifications. Always confirm bore measurements before installation to ensure proper fitment and performance.
Specifications
- Brand: KB Pistons
- Manufacturer Part #: KB425C.020
- UPC: 800745067739
- Bore Size: .020 oversized
- Compression Ratio: 8.8:1
- Engine Displacement: Twin CAM 88ci
- Length: 9.5 in
- Width: 4.8 in
- Height: 4.6 in
- Weight: 2.5 lbs
- Country of Origin: Mexico
Common questions
What compression ratio is this piston designed for?
This Kb Pistons hypereutectic cast piston is engineered for an 8.8:1 compression ratio, suitable for stock to mild builds on pump fuel.
Is this piston a direct replacement for my Twin Cam 88ci?
This piston is designed for Twin Cam 88ci engines with a .020 oversized bore. Always verify your current cylinder bore size before ordering.
Will I need to retune my motorcycle after installing these pistons?
Any change to engine internals, including pistons, can affect air/fuel mixture. A dyno tune is recommended to optimize performance and ensure engine longevity.
Ordering from Vtwinbikers
- Brand new, sourced through authorized US distribution — never used, never grey-market.
- Not sure it fits? Use Shop by Bike to filter by your year and model, or email us and we will confirm before you order.
- Harley-Davidson and Indian Motorcycle is all we do, so you are talking to people who ride what you ride.
| BRAND | Kb Pistons |
| TYPE | Piston kits & Components |
| SKU | 824-01353 |
| WEIGHT | 2.5 lb |
| 8.8 | 1 Compression |
