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 ignition advance settings at various engine RPMs.
| Identifier | ExFiles\Box 102\5\ scan0030 | |
| Date | 25th April 1930 | |
| X5090 Ignition Advance (5.75 "China") | R.P.M. | Necessary Adv. for Max. Power | Necessary Adv. for 2% Drop. | Actual Advance (Static Setting = 10°) | |---|---|---|---| | 3500 | 47° | 40° | 40° | | 3250 | 44° | 38° | 40° | | 3000 | 42° | 34° | 40° | | 2750 | 39° | 32° | 40° | | 2500 | 35° | 27° | 40° | | 2250 | 33° | 25° | 37° | | 2000 | 33° | 25° | 34° | | 1750 | 31° | 24° | 32° | | 1500 | 31° | 23° | 28° | | 1250 | 31° | 23° | 23° | | 1000 | 26° | 18° | 17° | | 750 | 19° | 14° | 13° | | 500 | 15° | 9° | 11° | [Initials 'CAB' in bottom right corner] | ||