Eric,
I was not saying crank balancing allows higher revving. I am talking about
the effects of hi-speed revolutions and unbalanced crank/engine loads. A
fully balanced engine is "happier" at high rpms; but, it is not the key to
increasing overall engine speed. I think Harald and Bob were extrapolating
the potential benefits of balancing in relation to engine speed. I think
they
meant unbalanced crank load might be limiting their *normal* potential rpm
due to *vibration*. I don't believe they are inferring that balancing will
further
increase engine speed unless I misread their posts; If they were, you are
correct.
Whether or not the vibration is really crank whip, and whether it's limiting
how hard
they can push the engine is unknown to me.

Doug Jones

Eric wrote:
This thread could not be more off base. Sorry to any
one I may offend ahead of time, but the higher RPM engine has
>little to do with the balancing of the crank. Making a motor
>rev. higher and faster, is a mater of the bore VS stroke, and
>the abliliy of the motor to breath.