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).
Ignition timing specifications for automatic control, magneto, and battery systems.
| Identifier | ExFiles\Box 65\1\ scan0116 | |
| Date | 14th May 1925 | |
| X 8685 14.5.25. X.8680/5. EAC. IGNITION TIMING. X.3949. ---------------------------------------- Range of automatic control 28º Full battery retard 10º after top centre. Full magneto retard 12º before top centre. Point of synchronisation 16º " " " Full magneto and battery advance. 48º " " " the above figures referring to the hand advance. The coincidence of magneto and battery ignition occurs at 73º (out of 90º) advance of movement of hand control lever, 0º representing full retard. EFC. | ||