Camshaft Bearing sizes

I am trying to find the actual main journal sizes on Pre-war 6 cylinder camshafts. The 2 intermediate bearings are approximately 43mm diameter, and the front and rear ones appear to be 30mm, but I need an accurate size. Does anyone have a good size camshaft that they can measure accurately with micrometers and give me a true size. The one that I have is in very poor condition, and appears to have been ground undersize at some time in the past. I would assume that the Firebirds etc. have the same size journals, but only one intermediate. Thanks, Ian Hardaker Posted by IanHardaker 25/09/2013 00:37:58

Does anyone have a camshaft that they can measure? Posted by IanHardaker 28/09/2013 15:53:42

I have copies of the original Alvis works drawings for Sp25 and 12/70  The stated journal diams are ;   small ones  30mm    Â¬.057 to   ¬.070    the larger centre ones   43mm     ¬.045 to    Â¬.057  . As far as I know all prewar cams are the same in this respect. Probably postwar as well. Posted by jackclover 14/12/2013 22:36:55

Excellent, Thanks Jack. I am making a batch of CNC ground cams, and that's all I needed to finish the job! Posted by IanHardaker 15/12/2013 12:04:50