anyone know if the crank and flyweel are [sm=feedback.gif]ballanced together. And is it required to be done if installing a new flyweel.

 

Crank, pistons, rods, flywheel/flexplate/ hormonic dampner/balancer all get ballanced as a unit. You cant do just the crank because its the weight of the pistions/rods that makes the most difference.

All of that stuff goes to the shop.

If you are installing a new flywheel, it should be okay unless you are turning 6500+ rpm. If its still the stock rebuild and has never been redone, then it isnt needed.

 

why not balance the new fly to weigh the same as the one taken off?

 

wear will cause the internal parts to change their balance, plus balancers slip

 

If what you have is a 428 Super Cobra Jet you are REQUIRED to use the " cookie cutter" supplemental balancer. If you don't use this piece, it won't live and will shake itself to death. Dean

 

Quite true, but he was wondering about the flywheel, since its an external balance engine.. usually the flywheel and balancer are both made with an imbalance to them. If he uses a 428 balanced flywheel on a stock build that hasnt been rebalanced it should be ok.

Remember the 5.0L having a different balancer and flywheel than the earlier 302? Same thing. I dont think you should have to pull the engine and rebalance the entire reciprocatiing assembly because of the flywheel.
But you do have to use the correct parts on it or you will have junk.