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).
Performance specifications for a magneto's firing capability, timing, and operational silence.
| Identifier | WestWitteringFiles\M\2October1924-December1924\ Scan82 | |
| Date | 20th October 1924 guessed | |
| -3- Contd. (6) The magneto shall be c-apable of firing regularly in sequence the six 5.5 mm. third point spark gaps in air at a speed of 3500 r.p.m. in the fully advanced position. (7) The magneto shall similarly be capable of firing regularly in sequence six 5.5 mm. third point spark gaps in air at speeds of:- B. 210 r.p.m. for the advanced position (hand range only). C. 190 r.p.m. for the fully retarded position. 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 3 minutes. (8) The timing of the magneto break shall not be varied more than ± 2º by altering the primary point gap ± .004" from normal respectively. (9) The maximum possible silence of operation of the magneto is essential. EFC. | ||