jpooch00
Registered user
Twin cam engines with bucket and shim valve clearance adjustment have been around for over 40 years now, so this is proven to be reliable technology. Shim adjustment is a bit more fiddly than the screw and locknut, but is still possible for DIYers and likely to give a more consistent and accurate valve clearance.
Suggesting that this will cause the engine to become unreliable is groundless and pointless![]()
They haven't been used on Beemers until the HP2 Sport.
And I can't see any way that shims will give as accurate of a clearance as an infinitely adjustable screw, unless you use over sized ones that are individually hand-lapped to an exacting thickness to get identical clearances on the respective valves.



It's certainley the best selling in it's class and there must be more than just marketing hype to back this up.