ROCKET PERFORMANCE GARAGE LLC SKU: 276-02060

Rocket Performance Garage 128" Big Bore Cylinder Kit - Milwaukee-Eight 2017-2024

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About Rocket Performance Garage Llc

Rocket Performance Garage builds V-twin performance and custom parts, working in the modern bagger and Softail space.

The Rocket Performance Garage 128 cubic inch big bore cylinder kit is designed for 2017-2024 Harley Milwaukee-Eight engines, upgrading them from 107cc to 128cc. This kit includes USA-made cylinders and Wiseco forged pistons, matched for reliable power gains and enhanced street rideability.

Why riders pick this

  • Increases Milwaukee-Eight displacement to 128 cubic inches
  • Includes premium USA-manufactured cylinders
  • Wiseco forged pistons for strength and reliability
  • Designed for significant power and torque gains
  • Black powder-coated finish with machined fins for a factory look

When stock displacement just isn't cutting it, the Rocket Performance Garage 128" big bore cylinder kit is your answer for serious power. This kit transforms your 2017-2024 Milwaukee-Eight engine, increasing its displacement to 128 cubic inches for a dramatic boost in torque and horsepower. Crafted with precision in the USA, these cylinders are paired with high-quality Wiseco forged pistons, ensuring durability and performance that stands up to aggressive riding.

Unlock Your M8's True Potential

  • Increases Milwaukee-Eight displacement to 128 cubic inches
  • Includes premium USA-manufactured cylinders
  • Wiseco forged pistons for strength and reliability
  • Designed for significant power and torque gains
  • Black powder-coated finish with machined fins for a factory look

The Foundation for a High-Performance Build

Upgrading to a big bore kit is a fundamental step in building a high-performance Milwaukee-Eight. The Rocket Performance Garage 128" kit provides the robust foundation you need for a powerful engine. Professional installation is highly recommended, as big bore cylinder installation requires meticulous engine disassembly and precise machine work to ensure optimal performance and longevity. Pair this kit with a performance cam, high-flow air cleaner, and a proper dyno tune for a complete, unstoppable package.

Specifications

  • Brand: Rocket Performance Garage
  • Manufacturer Part #: 8-8102
  • Displacement Increase: 107cc to 128cc
  • Compression Ratio: 10.5:1
  • Piston Type: Wiseco forged
  • Length: 9 in
  • Width: 8 in
  • Height: 20 in
  • Weight: 25 lbs
  • Country of Origin: USA

Common questions

What Milwaukee-Eight engines does this kit fit?

This Rocket Performance Garage 128" big bore kit is specifically designed for 2017-2024 Harley-Davidson Milwaukee-Eight (M8) engines.

Is professional installation required for this big bore kit?

Yes, big bore cylinder installation requires engine disassembly, precise measurements, and careful assembly. We strongly recommend having a qualified Harley technician or performance shop handle this job.

Will I need to upgrade my fuel management and cam?

Absolutely. A significant displacement increase like this kit provides will necessitate a performance cam, a high-flow air cleaner, a fuel tuner, and a custom dyno tune to ensure optimal performance, reliability, and prevent engine damage.

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.
BRANDRocket Performance Garage Llc
TYPEEngine
SKU276-02060
WEIGHT25.0 lb
Please contact us to confirm fitment for your specific motorcycle, or check the product title for compatibility notes.
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