KPMI .625 Lift H.T. Steel Retainer Valve Spring Kit - Harley Milwaukee-Eight Touring & Softail
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.
Optimize your Milwaukee-Eight engine's valve train with the KPMI .625 Lift Valve Spring Kit, featuring robust heat-treated steel retainers. These springs are crafted from premium Kobe Super-Clean chrome silicon wire, then heat-treated, stress-relieved, and shot-peened for maximum durability. Engineered to handle high-RPM loads, this kit ensures consistent valve timing and prevents valve float, crucial for performance V-twins.
Why riders pick this
- Premium Kobe Super-Clean chrome silicon wire for strength
- Heat-treated and stress-relieved for long-term durability
- Shot-peened for superior fatigue resistance
- Designed for .625 lift camshafts
- H.T. steel retainers for robust valvetrain stability
For riders pushing their Milwaukee-Eight engines, a high-performance valve spring kit is essential to maintain valvetrain stability. The KPMI .625 Lift Valve Spring Kit with H.T. steel retainers provides the strength and consistency needed to support more aggressive camshafts and higher RPMs. This kit is built to withstand the rigorous demands of performance riding, ensuring precise valve control and preventing detrimental valve float.
Built for Demanding V-Twin Performance
- Constructed from premium Kobe Super-Clean chrome silicon wire
- Heat-treated and stress-relieved for exceptional durability
- Shot-peened finish enhances fatigue resistance under high loads
- Designed for .625 lift camshaft applications
- Engineered to maintain consistent valve timing across the RPM range
Essential for High-Performance Builds
When upgrading your Milwaukee-Eight engine, especially with a higher-lift cam, stable valve springs are a non-negotiable component. This KPMI kit provides the foundation for reliable power delivery and extended engine life under performance conditions. For a complete and robust valvetrain, consider pairing these springs with KPMI's high-tensile rocker arm tower studs and cylinder studs, creating an engine that's ready for anything you throw at it.
Specifications
- Brand: KPMI
- Manufacturer Part #: 20-21850
- Length: 6 in
- Width: 2.25 in
- Height: 1.75 in
- Weight: 8 lbs
Common questions
What makes KPMI springs different from stock springs?
KPMI springs are specifically engineered for their application, utilizing advanced processes like shot-peening and stress-relieving, along with premium materials, to optimize performance and durability beyond factory specifications.
Do I need a special tool for installation?
Yes, professional valve spring installation typically requires a spring compressor tool and knowledge of proper seat pressure. If you are unfamiliar with cylinder head work, we recommend having a qualified technician perform the installation.
Will this kit fit my Harley-Davidson Touring or Softail model?
This kit is designed for Harley-Davidson Milwaukee-Eight Touring and Softail models. Please use our Shop by Bike tool to verify fitment for your specific year and model before purchasing.
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 | 191-27793S |
| WEIGHT | 8.0 lb |
