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).
From EFC requesting ignition timing diagrams for the 40/50 and 20 HP models.
| Identifier | ExFiles\Box 37\1\ scan 242 | |
| Date | 12th October 1923 | |
| X3949 To By/Shn. from EFC. EFC2/T12.10.23. X928 X3949 As arranged in conversation with you a day or two ago, you are getting out for us ignition timing diagrams for the 40/50 and 20 H.P., showing the magneto and battery ignition ranges of advance, including the automatic advance in the latter case - these diagrams to be on the lines suggested. EFC. | ||