Wiseco 1340 EVO Big Twin 8.5:1 Compression Piston Kit - Harley Evolution Touring & Softail
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.
Maximize the potential of your 1340cc Evolution Big Twin with this Wiseco forged piston kit, designed for an 8.5:1 compression ratio. Engineered from high-silicon, low-expansion aluminum, these pistons deliver exceptional strength and superior heat transfer. This kit provides a robust foundation for reliable performance in your Harley Touring, Softail, or Dyna.
Why riders pick this
- Forged high-silicon aluminum for durability
- 8.5:1 compression for 1340cc EVO Big Twin
- Diamond-turned finish ensures precise fit
- Compatible with various cylinder bore types
- Reduced weight for improved engine response
- Designed for Harley Evolution Touring & Softail
When it's time to refresh or upgrade your Evolution-powered Harley, Wiseco pistons are a go-to choice for their proven durability and performance. These 8.5:1 compression pistons are designed to work seamlessly with pump gasoline and provide a robust upgrade over OEM cast units. The precision manufacturing ensures consistent fitment and long-term reliability, whether you're cruising the highway or hitting the backroads on your Dyna, Softail, or Touring rig.
Engineered for Evolution Performance
- Forged high-silicon aluminum for superior strength and thermal management
- 8.5:1 compression ratio optimized for everyday street use
- Diamond-turned finish for precise cylinder wall sealing
- Compatible with a range of cylinder bore types, including cast iron and Nikasil
- Reduced weight compared to stock cast pistons for improved response
A Foundation for Power
Installing a Wiseco piston kit is a smart move for any rider looking to rebuild their 1340cc EVO Big Twin with confidence. The advanced manufacturing processes and material science behind these pistons mean you're getting a component that can handle the rigors of V-twin life. Pair this kit with a fresh top end for a noticeable improvement in engine longevity and consistent output on your Harley-Davidson.
Specifications
- Brand: Wiseco
- Manufacturer Part #: K1642
- Engine: 1340cc Evolution Big Twin
- Compression Ratio: 8.5:1
- Weight: 2.975 lbs
Common questions
What compression ratio do these Wiseco pistons offer?
This Wiseco piston kit provides an 8.5:1 compression ratio, which is ideal for 1340cc Evolution Big Twin engines running on pump gasoline.
Can these pistons be used in different cylinder types?
Yes, these Wiseco pistons are compatible with cast iron, chrome, Nikasil, and boron composite cylinder bores, offering broad application versatility.
Will these pistons require a special fuel or tune?
The 8.5:1 compression ratio is suitable for standard pump gasoline. However, any significant engine modification should be followed by a dyno tune to ensure optimal performance and engine health.
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 | K1642 |
| WEIGHT | 2.97 lb |
| 8.5 | 1 Compression |
