Wiseco 1340 EVO Big Twin 10:1 Compression Piston Kit - Harley Evolution
About Wiseco
Wiseco has forged pistons in Mentor, Ohio since 1941, supplying everything from factory race teams to big-bore street builds. Forged construction is what lets a V-twin survive higher compression and more cylinder pressure than the stock cast piston was designed for.
Give your 1340cc Harley EVO Big Twin the performance boost it deserves with this Wiseco Forged Piston Kit. Designed for a 10:1 compression ratio, this kit delivers a noticeable increase in power and responsiveness, perfect for riders looking to maximize their Evolution engine's output. Each piston is forged from high-silicon aluminum for ultimate strength.
Why riders pick this
- Achieves 10:1 compression for increased power
- Forged high-silicon aluminum for superior strength
- Precision diamond-turned finish for optimal fit
- Compatible with all common cylinder bore types
- Reduces weight and improves heat management
When you're building a performance-oriented 1340 EVO, the right piston kit is critical. Wiseco's forged pistons offer superior durability and thermal management compared to cast factory units, ensuring your engine can handle the increased demands of higher compression. This kit provides a solid foundation for a powerful and reliable engine build.
Engineered for Big Twin Power
- Forged high-silicon, low-expansion aluminum for exceptional strength and longevity
- Precision diamond-turned finish for optimal ring seal and consistent cylinder bore fitment
- Compatible with a variety of cylinder bore types: cast iron, chrome, nikasil, and boron composite
- Reduced reciprocating weight for quicker engine response and improved heat dissipation
Maximize Your EVO's Potential
A 10:1 compression ratio is a popular choice for 1340 EVO Big Twins, offering a significant performance bump without excessive stress on other engine components. To fully capitalize on this upgrade, consider pairing these pistons with a performance cam, free-flowing exhaust, and a professional dyno tune to ensure optimal air/fuel delivery and ignition timing.
Specifications
- Brand: Wiseco
- Manufacturer Part #: K1666
- Compression Ratio: 10:1
- Engine: 1340cc EVO Big Twin
- Weight: 2.8752 lbs
Common questions
Will this 10:1 compression ratio require a special fuel?
A 10:1 compression ratio typically requires premium octane fuel to prevent pre-ignition or knocking. Always consult your tuner for specific fuel recommendations for your complete build.
Is this a bolt-on replacement, or does it require machining?
While these pistons are designed to fit 1340cc EVO Big Twin engines, proper installation often requires professional cylinder inspection, honing, or boring to ensure correct clearances. Consult your mechanic.
What other upgrades complement this piston kit?
To fully utilize the 10:1 compression, consider a performance camshaft, an upgraded ignition system, a free-flowing exhaust, and a custom dyno tune to optimize your engine's performance.
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 | Wiseco |
| TYPE | Piston kits & Components |
| SKU | K1666 |
| WEIGHT | 2.87 lb |
| 10 | 1 Compression |
