KPMI Black Diamond Exhaust Valve - Evolution Harley-Davidson
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.
Unleash the full potential of your Harley Evolution engine with a KPMI Black Diamond exhaust valve. Precision-forged from stainless steel, this valve is engineered for riders who demand superior performance and longevity from their V-twin powerplant.
Why riders pick this
- Precision-forged stainless steel construction
- Black Diamond surface impregnation for extreme hardness
- Superior wear and corrosion resistance
- Reduced friction for extended valve life
- Optimized flow characteristics for better performance
This KPMI Black Diamond exhaust valve is more than just a replacement part; it's an upgrade for your Harley Evolution engine. Each valve undergoes a proprietary German impregnation process, hardening the surface for exceptional durability where it matters most. Experience reduced friction and superior wear resistance, ensuring your Evolution motor performs reliably ride after ride.
Engineered for Endurance
- Precision-forged from a single piece of stainless steel for maximum strength
- German Black Diamond impregnation process hardens the surface to .002" depth
- Delivers superior wear resistance and corrosion protection over chrome or nickel plating
- Reduced friction promotes longer valve life and consistent performance
- Optimized for excellent flow characteristics within your cylinder head
Performance You Can Trust
Whether you're refreshing a high-mileage Evolution or building a performance engine, the KPMI Black Diamond exhaust valve provides a solid foundation. Its robust construction and advanced surface treatment are designed to handle the demands of a performance Harley-Davidson, giving you confidence in every twist of the throttle. Pair it with other KPMI valvetrain components for a complete, integrated upgrade.
Specifications
- Brand: KPMI
- Manufacturer Part #: 20-4170
- Length: 3.55 in
- Width: 4.7 in
- Height: 1.55 in
- Weight: 0.19 lbs
Common questions
Is this an intake or exhaust valve?
This is an exhaust valve. KPMI manufactures separate part numbers for intake valves, which should be ordered accordingly.
What makes Black Diamond valves different from standard stainless valves?
The proprietary German Black Diamond impregnation process hardens the valve surface to a depth of .002 inches. This treatment significantly reduces friction and improves wear resistance beyond what standard chrome or nickel plating offers.
Will this valve fit my Harley-Davidson Evolution engine?
This valve is specifically engineered for Harley-Davidson Evolution engines. For exact model year compatibility, please confirm fitment using our Shop by Bike tool.
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 | 191-17002 |
| WEIGHT | 0.19 lb |
