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 curves for an EAC engine, with Hispano curves for comparison.
| Identifier | ExFiles\Box 182\M20\M20.2\ img005 | |
| Date | 31th March 1929 | |
| IGNITION CURVES. CURVES. 1-2-3. EAC. ENG. MEAN POSNS FOR MAINTAINING OUTPUT. HISPANO CURVES FOR COMPARISON. DEGREES ADVANCE REVS/MIN. BATTERY ONLY (1) MAG ONLY (2) BOTH IGNS. (3) HISPANO 1 PLUG HISPANO 2 PLUGS. S.H.Z.ARMER 31-3-29 | ||