Comparative table of performance data for various magneto models.
| Identifier | WestWitteringFiles\F\March1921\ Scan63 | |
| Date | 6th August 1919 | |
| R.R. 63 (50 T) (S F. {Mr Friese} 846. 6-8-19) G 2459. -2- A. {Mr Adams} Magneto. Degrees of make Maker's make advanced Maker's break advanced Our break advanced Our break retarded Lowest speeds for 5.5 mm. Remarks. Adv. Cent. Rtd. Watford. 154.5 -57° 97.5° 97.5 131.5 150 250 340. Magneto No.45638 " 155 -59° 96° 94.5 128.5 156 226 320. " 45168. " 163.5 -78.5° 85° 85° 117° 160 140 136 Maker's range. " 160.0 -92° 67° 96 130 160 150 150. Retd posn. same as maker's Adv. posn. 29° later than maker's. R.Bosch. 82.5 +11.5° 94° 94 128 260 170 246. Adv. posn. same as makers Retd posn. 2.5° earlier than makers. U.S.A. Bosch. 153 -53.5° 99.5 99.5 133.5 120 162 240. Adv. posn. same as makers. Retd posn. 3.5° earlier than maker's. U.S.A. Bosch. 155.5 -79° 76.5 -- -- 150 250 530. Maker's range. Dixie. 73.5 -20° 53.5° -- -- 180 160 185. Low speed sparking unaltered by advancing. Conner. 78 +14.5° 92.5° 107 141 350 260 170. Retd. posn. same as maker's Adv. posn. 14.5° later than maker's. B.T.H. 100.0 -27.5° 72.5° 62.5 96.5 244 192 220. Datum slightly indefinite. Full adv. not secured owing to fouling. Contd. | ||
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).