Join Date: Aug 1998
Location: Waldorf Md. USA
"Balancing is not necessary for the average engine rebuild" ......
This is true if all of the original, stock parts that came with the engine are reused, or if the replacement pistons, rods etc, all weigh exactly the same as the originals.
As soon as you buy a new, lighter piston, or a different crankshaft...all bets are off. The crankshaft is balanced to match the weights of the components that are used with it. The factory actually does a pretty good job. But, most newer replacement pistons are a lot lighter than the factory ones. If you are buying all new parts...crank, rods etc, there is no way I would not buy it as a balanced assembly, or have it balanced after you get it at the balance shop of your choice. Most of the new cranks available...Eagle, Scat etc are only partially balanced from the factory.
Hope this helps,
Advanced Automotive Machine
1971 Chevelle "Heavy Chevy" original owner