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).
Specification sheet comparing present and revised ignition timing settings for the Phantom engine.
| Identifier | ExFiles\Box 37\1\ scan 315 | |
| Date | 27th September 1928 | |
| X 3949 27.9.28. PHANTOM IGNITION TIMING. x928 XC680 Present. RL/M19.9.28. Battery hand range. 30° 30° Magneto hand range. 8° 15° Auto range. 28° to 30° 25° Full battery retard. 10° A.T.C. 10° Full magneto retard. 12° B.T.C. 5° Full battery } 48° to 50° B.T.C. 45° advance. Full magneto } advance. Timing angles reckoned on engine. Battery hand advanced, auto retarded. 20° B.T.C. 20° Magneto hand advanced, auto retarded 20° B.T.C. 20° Battery auto } 18° to 20° B.T.C. 15° advanced, hand retarded Magneto auto } 40° to 42° B.T.C. 30° advanced, hand retarded EFC. | ||