Yes lozza it probably did come from old 'slide rule'. i used those principles on a BMW 500cc R50 that i built up for road racing in the sixties, in an sffort to get some torque in the lower rev range. unfortunately due to other mods the max power came in just before heads came off valves at 8000 rpm plus! It was a verry expensive excersize in futility. By the way, any-one who knows Terry Law from down around Carlton way ask him how fast it went down conrod straight! cheers wally.
