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).
The high and low-speed sparking characteristics of various magneto models.
| Identifier | ExFiles\Box 4\5\ 05-page321 | |
| Date | 3rd November 1924 guessed | |
| -5- Contd. (12) High speed sparking characteristics. The highest speed at which the magnetos were capable of firing regularly in sequence six 5.5 mm. three-point spark gaps in air in the fully advanced position were 2650, 4400 and 3500 r.p.m. (13) Low speed sparking characteristics. The lowest speeds at which the magnetos are capable of firing regularly in sequence six 5.5 mm. three-point spark gaps in air in each of the three positions :- (a) Fully advanced. and (b) Central (c) Fully retarded. of the contact breaker lever, were in accordance with the following table :- SPEED. MAGNETO. Advanced. Central. Retarded. Watford (Representa- tive average figures). 280 230 210 R.{Sir Henry Royce} Bosch (Av: of two) 280 240 270 B.T.H. 250 190 160 Corresponding results taken for the Scintilla magnetos in the fully advanced position (hand range), corresponding to the central position above, and in the fully retarded position corresponding to the retarded position above, are as follows :- SPEED Fully advanced MAGNETO (hand range) Fully (Central) retarded. AM6-A (Av. of 4) 180 300 AG6-A (latest magneto) 160 290 Contd. | ||