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).
Graph of ignition advance curves for various Phantom engine configurations.
| Identifier | ExFiles\Box 42\4\ Scan059 | |
| Date | 2nd December 1924 | |
| SHEET 2A IGNITION ADVANCE ON FLYWHEEL (DEGREES) STD. PHANTOM (COMP. RATIO = 4.1 : 1) ALUM. PHANTOM (A.45 : 1) ALUM. PHANTOM WITH 1.600 DIA. VALVES. (COMP. RATIO = 4.69 : 1) ALUM. PHANTOM WITH HEAD TO L.E.C. 2230 (COMP. RATIO = 4.95 : 1) IGNITION ADVANCE CURVES. BOTH IGNITIONS ARE SYNCHRONISED IN ALL CASES. R.P.M. OF ENGINE. IGNITION ADVANCE ON FLYWHEEL (DEGREES) AHD 2.12.24 | ||