Kibblewhite 20-23450 Rocker Shim Conversion Spring Kit for Milwaukee-8 Engines

The Kibblewhite KPMI Rocker Shim Conversion Spring Kit is engineered specifically for Harley-Davidson Milwaukee-8 engines to enable high-lift camshaft applications up to 0.675" valve lift. This innovative system replaces traditional valve spring retainers with a dual spring design and lightweight retainer that incorporates a hardened steel shim.

Key Features:

• Dual spring system with lightweight retainer housing a 9.5mm hardened steel shim
• Significantly increased rocker wipe area compared to standard 6mm valve stems
• Enables use of larger lift camshafts previously incompatible with 6mm valve stems
• Adjustable design allows up to 0.060" of spring shimming for custom pressure tuning
• Variable rocker shim thickness permits effective stem protrusion adjustment
• High-temperature steel construction for durability under extreme conditions

Important Installation Requirements:

• Valve Modification: KPMI recommends "tipping" (shortening) the valve tip to maximize shim contact in the retainer
• Stem Protrusion: Expect approximately 0.100" increase in effective stem protrusion when using this shim system
• Valve Guide Compatibility: Must be used with KPMI's newer style Milwaukee-8 valve guides, which are shortened specifically for 0.675" valve lift applications
• Performance Recommendation: When running large camshafts with increased valvetrain acceleration, KPMI strongly recommends titanium valves for maximum performance and reliability

This conversion kit provides engine builders with the flexibility to tailor spring pressures and lift capacity to meet specific performance goals while maintaining valvetrain stability in high-performance Milwaukee-8 builds.