The improved Compound , known as the Compound B67 , was intended primarily to address the perceived performance limitations of the original model .
This was achieved by adding 4 mm to the cylinder bores , thereby increasing engine capacity from 1185 cc to 1340 cc .
The improved Compound , known as the Compound B67 , was intended primarily to address the perceived performance limitations of the original model , and this was achieved by adding 4 mm to the cylinder bores , thereby increasing engine capacity from 1185 cc to 1340 cc .