We knew that the solution lay in an exact half ring / valve stem groove profile match, but also recognized that the higher RPMs and reduced valve stem diameter associated with the 4 Valve engines required additional support along the upper valve stem groove area. Having settled on a design, R&D and testing for the 4V collets took us beyond the dyno and onto the racetrack.
We worked extensively with Scott Dormier - Pro Twins series contender, Munroe Motors' pair of Pro Thunder 748's and winner of the Pro-Thunder series 2001 At the ultimate test in reliability - Daytona - all MBP bikes performed without failure and without valve adjustment.
Given the higher stress inherent in the 4V engine, we feel that the requirement to modify the opening shim (see Installation & Tools) is easily offset by the substantial gains in reliability. While dealers and mechanics can take immediate advantage of the extraordinary gains in valve train reliability immediately, shims designed to fully exploit the MBP 4V design will be available for individual enthusiasts in the fall of 2001.
Existing technology: click here
Summary: click here
