But then I am quite sure there is not much left in these engines that was made by BMW. Most of the internals were probably made just before Y 2K or later. And the bikes that are raced these days started as lowly sv R 52 with 12 hp and got all replica parts you can get, like big alu cylinders, racing cams, new heads, new cranks and so on. You really do not know what you see on the race track, loads of fakes really - but nobody tells you openly what was done !!
Vic