KPMI White Diamond Oversize Exhaust Valve - Milwaukee-Eight 1.284 in - Harley M8
About KPMI
Kibblewhite Precision Machining supplies valves, valve springs, guides and complete top-end kits used by professional V-twin engine builders. Its black diamond valves and spring kits are a standard specification on high-lift cam builds.
This KPMI White Diamond exhaust valve is precisely sized at 1.284 inches oversize, engineered for Harley Milwaukee-Eight (M8) engines. It's the ideal choice for high-performance builds or engine rebuild applications where optimized airflow is critical. The White Diamond coating ensures superior durability and heat resistance, essential for demanding V-twin conditions.
Why riders pick this
- Oversize 1.284 inch diameter for M8 engines
- White Diamond coating resists heat and wear
- Ideal for high-performance builds and rebuilds
- Enhances exhaust flow and engine efficiency
Unlock greater potential from your Milwaukee-Eight engine with the KPMI White Diamond oversize exhaust valve. Measuring 1.284 inches, this valve is designed for M8 engines undergoing performance builds or rebuilds, allowing for improved exhaust flow and enhanced engine efficiency. The advanced White Diamond hard coating is a key feature, providing exceptional resistance to heat and wear. This makes it a crucial component for riders pushing their M8 engines to the limit, ensuring longevity and consistent performance even in the most demanding conditions.
Built for High-Performance M8 Engines
- Oversize 1.284 inch diameter for enhanced exhaust flow
- White Diamond hard coating for superior heat and wear resistance
- Designed for Milwaukee-Eight high-performance and rebuilt engines
- Contributes to improved engine efficiency and power output
Optimize Your M8 Rebuild
Choosing an oversize exhaust valve like this KPMI White Diamond unit is a strategic move for any serious Milwaukee-Eight engine builder. It allows for porting and optimizing cylinder head flow, which is fundamental to extracting maximum power from your V-twin. Keep in mind that installing oversize valves typically requires professional machining of your cylinder heads to accommodate the larger diameter. Consult with your engine builder to ensure proper fitment and performance gains for your custom M8 project.
Specifications
- Brand: KPMI
- Manufacturer Part #: 20-21017H
- Size: 1.284 inch oversize
- Length: 3.5 in
- Weight: 0.2 lbs
Common questions
Will this oversize exhaust valve fit a stock Milwaukee-Eight engine?
No, this 1.284 inch oversize valve is intended for rebuilt or ported M8 cylinder heads. Stock engines use standard-size exhaust valves.
What are the benefits of the White Diamond coating?
The White Diamond coating is a hard ceramic layer that significantly resists heat and wear, improving the valve's durability and lifespan in high-performance and high-temperature applications.
Do I need new valve seats for this oversize valve?
Yes, installing oversize valves typically requires machining the cylinder heads and installing new valve seats to properly accommodate the larger diameter and ensure correct sealing and 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 | KPMI |
| TYPE | Engine |
| SKU | 191-17047 |
| WEIGHT | 0.2 lb |
