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 detailing the lowest speeds in RPM for regular firing of various magnetos.
Identifier | ExFiles\Box 4\5\ 05-page240 | |
Date | 25th July 1922 | |
VG30 3D. 25.7.22. X.430. MAGNETOS. TABLE OF LOWEST SPEEDS IN R.P.M. FOR REGULAR FIRING ON 3RD TEL. GAPS IN AIR. CHAIN DRIVE. N.B. Test range between advance and retard 34° in all cases. | Magneto. | Type & No. | X. No. | Lowest speeds. | Remarks. | |---|---|---|---|---| | | | | Adv. | Cent. | Retd. | | | U.S.A. Bosch. | ZR.6. Ed.{J. L. Edwards}19 3385100. | 3916 | 56 | 105 | 150 | Advanced position same as makers. Retard position 2° earlier than makers | | Watford. | EO6c. 50410. | 4181 | 210 | 200 | 200 | Advance and retard limited by movable sleeves attached to cam ring. Therefore range the same as makers. | | Watford. | EL06. 55044. | 4275 | 67 | 68 | 69 | Advance and retard limited by movable sleeves attached to cam ring. Retard position same as makers. Advance position 28° later than makers. | | Scintilla | AG-6-A 21523. | 4187 | 250 | 260 | 280 | } Refers to makers hand range only. 17.5°, 20° and 20.5° respectively. | | Scintilla | AM-6-A 26485. | 4187 | 220 | 330 | 410 | | | Scintilla | AM-6-A 34937. | 4187 | 150 | 200 | 280 | | | Scintilla | AML-A 29531 | 4187 | 140 | 190 | 230 | As above | | Scintilla 19.5.24. | AM6-A 2x533 | 4187 | 245 | 300 | 355 | } 19°, 20° & 19° respectively | | Scintilla | AG6-A 34903 | 4187 | 160 | 220 | 290 | | | ||