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).
Table of figures for automatic ignition advance for the MAG.2 engine at various speeds.
| Identifier | ExFiles\Box 69\2\ scan0135 | |
| Date | 21th August 1924 | |
| X.8770 21.8.24. X.3949. AUTOMATIC ADVANCE FOR MAG.2 ENGINE. (Figures supplied by Hs.{Lord Ernest Hives - Chair} showing maximum and minimum engine degrees B.D.P at which maximum power is maintained for various speeds). B.D.P. Speed. Maximum. Minimum. 500 22° 15° 650 26 20 750 31 24 1000 39 29 1250 44 35 1500 46 39 1750 47 39 2000 51 41 2250 54 44 2500 56 47 3000 58 50 Note 1. Engine degrees and speeds throughout. Note 2. 2 to 3% less advance required when using both ignitions. EFC. | ||