I am in search of a new block since my build had all of the wrist pins migrate into the cylinder walls, (see thread 460 What happened?), and destroyed the old block. I have been looking at the later block. The external balanced crank doesn’t have the heavy counterweight lobes on it, so I presume that it is lighter. Has anybody done any tests to see if it will deliver more snap? It seems that if it is lighter that it would spin more freely and thus be more efficient. (Just thinking out loud)

 

probably not very much difference as instead of having the weight in the crank counterweights, they use a big counterweight behind the balancer to compensate for the difference. so overall as a complete unit, they probably weigh about the same.

rgds
Mike