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).
The ignition advance required to maintain power for an E.A.C. engine.
| Identifier | ExFiles\Box 37\1\ scan 254 | |
| Date | 12th July 1923 | |
| B.R. 493A (40 H) (SL 42 12-7-23). J.H., D.{John DeLooze - Company Secretary} EXPERIMENTAL REPORT. Expl. No. REF: Hs{Lord Ernest Hives - Chair}/ACL1.4.24. E.A.C. ENGINE. Ignition advance required to maintain power. Figures obtained from 3-EAC.1 Engine - 4.6 comp: ratio. (1) Battery only. (2) Magneto only. (3) Both ignitions synchronised. In each case the positions given as max. and min. are where power is maintained, and 1° from 'fall off', The average range for max. power is 8°. (1) Battery only. REVS. LBS. MAX. MIN. MEAN. 2500 113.5 54° 47° 50.5° 2250 124 53° 43° 48 2000 134 50° 42° 46 1750 139.5 46° 40° 43 1500 143.5 44° 38° 41 1250 145 42° 35° 38.5 1000 149 39° 32° 35 750 150 36° 27° 31.5 650 148 33° 26° 29 (2) Magneto only. 2500 112.5 --- 44° 48° 2250 123.5 --- 43° 46 2000 135 47° 39° 43 1750 140 45° 38° 41.5° 1500 144 43° 36° 39 1250 146 41° 33° 37 1000 148.5 38° 32° 34.5 750 151 36° 28° 32 650 148 31° 24° 27.5° CONTD:- | ||