2 piece cranks
 

hi,
was just wondering how many people out there run 2 piece cranks (either precision or extreme rotary ones).
have heard differing opinions on various problems associated with them and was interested to know other peoples findings.
we ran one in an alcohol drag engine for a half dozen or so pulls on a chassis dyno, seemed to make a little more power but when we pulled apart the engine to check the crank it had fretted on the tapered section and welded itself together. have gone over everything with fine tooth comb but havent got a definitive cause at the mo but its looking like not enough touque on the front pulley bolt. has been repaired so may try again in future.

anyone else care to share experience, good or bad.

cheers
cory