[RICK LAKE]

BT Snake Hersh zero balance is what the rotating assembly is what you want. Has the least vibration when the assmbly is spinning. You want the complete rotating assembly, this is the dampener, spacer, crank, rods, pistons, flywheel, rings and bearings. You either add or remove weight to balance the assembly to "0"
External balance motor have an outside weight on the dampener and possible the flywheel also. The danpener has weight added or drilled out to balance the assembly, same with the flywheel. IMO the problem with external setup is that if you have a problem where you need to replace the flywheel or dampener you need to have it balanced to match the motor. If you get an internal motor balance you just need to match the old weight of what you are replacing. The is a SMALL fudge factor for maybe a couple of grams. to keep the motor smooth. This is for a street motor, 6,000 rpm limit. Over this number and you need an internal balance with all the parts to help extend the life of the motor. If you have money, ATI will custom balance the rotating assembly with the motor running. Nascar guys have this done to have motors live at 9,400 rpms. Rick L.