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).
Comparative table of performance data for various magnetos, continued from a previous page.
| Identifier | ExFiles\Box 48\3\ Scan095 | |
| Date | 10th December 1920 | |
| -2- Contd. TABLE DATA Column Headers: Magneto., Type and Number., X. No., Lowest speeds. Adv., Lowest speeds. Cent., Lowest speeds. Retd., Remarks. Row 1: Magneto.: R. {Sir Henry Royce} Bosch. Type and Number.: Z.R.6. 2571556. X. No.: 427. Lowest speeds. Adv.: 260 Lowest speeds. Cent.: 170 Lowest speeds. Retd.: 246. Remarks.: Advanced position same as maker's. Retarded position 2.5º earlier than maker's. Row 2: Magneto.: U.S.A. Bosch. Type and Number.: Z.R.6. 2998784. X. No.: 3916. Lowest speeds. Adv.: 120 Lowest speeds. Cent.: 162 Lowest speeds. Retd.: 240. Remarks.: Advanced position same as maker's. Retarded position 3.5º earlier than maker's. Row 3: Magneto.: Dixie. Type and Number.: Aero 648. 718237. X. No.: 3724. Lowest speeds. Adv.: 180 Lowest speeds. Cent.: 180 Lowest speeds. Retd.: 185. Remarks.: Sparking speed unaltered by advancing or retarding, hence figures as first obtained on maker's range are representative. Row 4: Magneto.: Conner. Type and Number.: C.M.1 X. No.: 4210. Lowest speeds. Adv.: 350. Lowest speeds. Cent.: 260. Lowest speeds. Retd.: 170. Remarks.: (Weighted averages of two sets of figures) Retarded position same as makers, this position giving minimum regular sparking speed. Further retard again increased speed rapidly. Advanced position 14.5º later than maker's. Row 5: Magneto.: B.T.H. Type and Number.: F.M.6. R.311941. X. No.: 3515. Lowest speeds. Adv.: 244 Lowest speeds. Cent.: 192 Lowest speeds. Retd.: 220. Remarks.: Advanced position 10º earlier than maker's. Further advance limited by fouling of timing lever, but apparently would further reduce the minimum sparking speed in retarded position. Retarded position 21.5º earlier than maker's. Footer (upside down): H.R. 251A (100) ('S. H. {Arthur M. Hanbury - Head Complaints} 798. 10-12-20) C 1947 | ||