All cranks have counterweights which are generally very slab sided. this causes a slowing effect when they are forced through all the oil and gases in the sump at high engine revs. To alleviate this restriction we sharpen the edges of the counterweights to a virtual knife-edge. which allows a much easier passage through the sump at high revs. This makes the engine much smoother and dynamic increasing rev-ability and engine longevity. The front pulley and clutch cover are also part of the rotating assembly with the crank. when these are balanced they spin much more truly giving a smoother engine. An out of balance engine shortens life expectancy and gives a harsh feeling when revving hard. If the donor crankshaft needs grinding then this is charged as an extra amount on top of the price shown. This product is exchange. Email Friend Price: £254.47