- Jul 11, 2004
I don't think this analogy applies. Yes the theory of resonance is sound, but that doesn't mean it's the dominant stressor in a crank. There was a good link posted to EvolutionM forums that showed it takes over 600hp on a 7 bolt EVO crank before early wear of the bearings showed up when using a solid pulley. The HP level matters because it affects the magnitude of the vibrations. BTW the EVO 7 bolt crank uses narrower main and rod bearings than a 6 bolt crank, so the bearings don't give as much support, and the EVO crank is 2 pounds lighter.
Early bearing failure occured after a track run or two. . . at 600hp. We're talking the flexing of the crank over thousands of miles. . . at 300-400hp. 'The engineers engineered the crank so well that it needs no damper'. Then they installed one at 200crank horsepower.