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).
Comparison report on the Scintilla Magneto Type AG-6-A (Larger Type), detailing its specifications against smaller models.
| Identifier | ExFiles\Box 48\2\ Scan163 | |
| Date | 4th September 1924 | |
| To R. {Sir Henry Royce} & E. {Mr Elliott - Chief Engineer} from EFC. {E. Fowler Clarke - Electrical Engineer} c. CJ. & FN. c. EY. EP. {G. Eric Platford - Chief Quality Engineer} Da. {Bernard Day - Chassis Design} X8795 EFC {E. Fowler Clarke - Electrical Engineer} 2/T4.9.24. X. 4187 - SCINTILLA MAGNETO TYPE AG-6-A (LARGER TYPE) NO. 34903. (Adapted by Messrs. Scintilla more nearly to comply with our general specification than the previous AG-6-A magneto, and than that of the smaller type AM-6-A machines previously received. This, for comparative trial with those smaller type magnetos on the EAC.2.engine). (1) The weight of this larger magneto is 14.5 lbs. as against 12.5 for the smaller one. (2) The mechanical and electrical design of the two magnetos is to all intents and purposes identical, one being very nearly a scale model of the other. (3) H.T. safety gap of both large and small magneto 11.5 mm. (4) The contact breaker timing in relation to the armature of the magneto is practically the same as for the small machine, this latter having been reported in our EFC {E. Fowler Clarke - Electrical Engineer} 1/T9.5.24. (5) The advance ranges of the two machines are in accordance with the following table :- Total. Auto. Hand. Larger machine. 57 38 19 Smaller " 53 33 20 an increase of the auto and the total of about 5°. The automatic advance characteristic of the large machine, in comparison with the small machine, has been already issued under cover of our EFC {E. Fowler Clarke - Electrical Engineer} 9/T27.8.24. (6)&(7) Endurance and short circuit tests of the magneto were O.K. Contd. | ||