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).
Whether improved car performance is due to drilling an air-valve or advanced ignition timing.
| Identifier | ExFiles\Box 13\3\ 03-page232 | |
| Date | 28th July 1930 | |
| COPY. X 7080 R.{Sir Henry Royce} From PN.{Mr Northey} c. to Sg.{Arthur F. Sidgreaves - MD} By.{R.W. Bailey - Chief Engineer} HS.{Lord Ernest Hives - Chair} PN.{Mr Northey}3/WT28.7.30. X. 7080 X. 5080. X. 459. Referring to R.5/M.10.7.30. Carburation. I think there is no doubt it will be found any increased acceleration and better consumption which Mr. De Salamanca alleged to obtain on his P.11 by drilling the air-valve to allow quicker action, was more contributed to by the fact that he had timed the ignition of his car considerably earlier than standard. I pointed out to him that although it may have happened not to be accompanied by the disadvantage such as detonation, in his case, the timing which is now accepted for standard cars is the one found best for general production, having regard to the inevitable small differences which may exist between engines etc. PN.{Mr Northey} | ||