More Rsi
Doug,
Good to see you are concerned about the RSI I get from the keyboard.
I wondered if the comment from the guy @ Scat was a bit of a 'throwaway' myself.
Balancing a V8 will always be compromise.
1 .You cannot balance the crank until you know the weights of Rods,Pistons,Pins,Rings,Bearings,Circlips,etc. If the motor has external balance( std 289/302/351/ etc) these must also be purchased & fitted prior to balancing.
2. With the"O" balance cranks as we call them the same applys, but you could use a neutral balance F/wheel&Damper that had been previously balanced, AFTER having balanced the internal components. Some folk do this on the basis that they wont have to rebalance when changing Flywheels etc.
3. The "Compromise" factor really kick.s in when you start to visualise what is happening during one rotation. At TDC the Big end of the rod has the balance pad facing in to the center of the crank, its companion rod on the same journal has its pad slightly outside the rod journals circle path, now as the crank rotates both pads will move outside that circle & 180 deg later both will move inside ( I realise that most higher quality rods dont have the pads but the heads/nuts of the cap bolts have the same effect). so at no point in actual operation does the crankshaft have a constant effective weight like it has on the balancer, and we have not even considered the rest of the rod,piston monkey motion yet!
When you start to think of the V8 as two 90deg V twins, seperated by a 90deg V4 with a flat plane crank you should start to come to terms with it.( See Keith your halfway there already).
Jac Mac