Originally posted by L8 Apexing Aussie:
0.5mm isn't worth the trouble. That won't do jack squat. 
I can see increasing valve lift by gringing off the back circle of the cam working very well. But that brings one question to mind.
Would that constitute a clearance issue between the valve heads and the pistons? Is the duratech an "interference" engine, where if a vlave is left open and the piston is moved tword TDC, would the piston contact the valve?
