Valve spring Kit, Rocker Shim Conv. System, Dual Spring, 0.675” Lift, HD®, M8™ (& CVO’s*) 2017-2024

*2023-2024 CVO’s check valve lift to determine compatibility with KPMI® spring kits

The KPMI® Rocker Shim Conversion Spring Kit for the Milwaukee-8 utilizes a dual spring system and a lightweight retainer that houses a standard Ø9.5mm hardened steel shim. The rocker arm rides directly on the shim surface and the 9.5mm diameter significantly increases the allowable rocker wipe area. This increase in wipe area provides the ability to utilize larger lift cams, that previously were unable to run on a 6mm valve stem.
The system is intended to be adjustable and allows for at least 0.060” of spring shims, tailoring the pressures and lift capacity to meet the engine builder’s needs. Additionally, the rocker shim thickness can be varied to adjust effective stem protrusion.
When larger camshafts are used, and valvetrain acceleration values increase, KPMI® strongly recommends running titanium valves for maximum performance.

IMPORTANT NOTE:
Modification Necessary:
To maximize shim contact in the retainer, KPMI recommends “tipping” (shortening the valve tip). See KPMI® installation instructions for more info.
Stem Protrusion:
There is anticipated to be a rough 0.100” increase in effective stem protrusion with the use of the shim.
Valve Guide Compatibility:
This system must be run with KPMI’s newer style M8 valve guides, which are shortened for 0.675” valve lift. See KPMI® installation instructions for more info.