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).
Diagram illustrating the ignition timing advance for battery and magneto systems.
| Identifier | ExFiles\Box 37\1\ scan 274 | |
| Date | 28th August 1924 guessed | |
| X.3949 70° 60° 50° 40° B.D.P. 30° 20° 10° RETARD. 0° 10° A.D.P. 20° BATTERY IGNITION ADVANCE. (FULLY ADVANCED AUTOMATICALLY) MAGNETO ADVANCE. (FULLY ADVANCED AUTOMATICALLY) BATTERY IGNITION ADVANCE. (FULLY RETARDED AUTOMATICALLY) MAGNETO ADVANCE. (FULLY RETARDED AUTOMATICALLY) IGNITION LEVER TRAVEL. E.A.C. II BATTERY AND MAGNETO IGNITION DIAGRAM. 70° 60° 50° 40° 30° 20° 10° 0° ADVANCE 10° 20° | ||