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).
Specifications for magneto operation, including minimum sparking speed and timing adjustments.
| Identifier | WestWitteringFiles\N\2October1925-December1925\ Scan275 | |
| Date | 8th November 1925 guessed | |
| -3- Contd. Note:- The minimum regular sparking speed can be taken to be that speed at which 100 consecutive sparks, without missing, are given by the magneto at some time within a period not greater than 5 minutes. (8) The timing of the magneto break shall not be varied more than ±3° by altering the primary point gap ± .004" from normal respectively. (9) The maximum possible silence of operation of the magnet-o is essential. (10) The direction of rotation of the magneto shall be anti-clockwise, looking on the driving end. EFC. | ||