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From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Continuation page of a memorandum proposing modifications to feeler gauges, plug settings, and cam designs for the Phantom model.

Identifier  ExFiles\Box 17\6\  Scan037
Date  9th May 1928 guessed
  
contd :-

-2-

Regarding the feeler gauges the .002 should be abolished altogether and replaced by .006 or something more useful.

The .030 should likewise go as we should not set plugs to this since we are increasing the compression ratio,

Regarding the cam lengths I am proposing that we make two forms to suit our rollerless tappets, 53 and 57 divisions long over the heavy accelerations, which are respectively one division longer than the inlet and exhaust we are at present using on the Phantom.

Camshafts can be made up for experiment with different angles between cams: diagrams seem best at 110º.

We are convinced that it is a mistake to endeavour to use the same cam for both inlet and exhaust, resulting in noise or some loss due to the inlet opening too early.

R.{Sir Henry Royce}
  
  


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