this might be a stupid question, but what makes it ok for us to use lightened flywheels without having the crank rebalanced?

 

i would assume since the weight of the flywheel is spread uniformly it doesn't make a significant impact on the balance of the rotating assembly in relation to the overall balance of the engine. now if the weight distribution of the flywheel wasn't spread evenly, it would definately make a HUGE impact.

 

This may not be the the answer, but people do flywheel/clutch all the time and never open the block

 

anyone else?

 

zero balance the flywheel and clutch assembly. Just an Idea.

 

Yeah, I'd imagine that the flywheel/clutch assembly is balanced close enough that it has a very small effect on the crank......
Brian