[schwarze-man]

Having read a fair amount about the huge increases in production of the Merlin, it seems to me that the often quoted need to work to tighter tolerances for Ford (UK) and Packard (USA) is a bit of a throw-away line. In the late 1930's Rolls-Royce worked to their company standards on many components. Their skilled fitters and machinists produced quality work. The critical clearances on parts like pistons, rings and bearings were well defined in the RR way and things like gear backlash were perhaps judged by very skilled men. However, the true mass production by motor car companies did require more definition of specification. Selective fitting of components to achieve fits was superceeded by better definition of finished size and surface finish so that, parts could be assembled without extra finishing or selective fitting. Also, there was a fair amount of redesign for the American produced Packard version. As RR expanded their own production plants, many of these changes were needed anyway as the skilled workforce was diluted by unskilled workers. I am also certain that RR learned quite a bit from the other car companies practices so that, the whole process was a mutual effort to the benefit of all. Cheers

SM