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).
Instructions regarding minimum low-speed sparking speeds for magnetos.
| Identifier | ExFiles\Box 48\2\ Scan224 | |
| Date | 29th June 1920 | |
| RR 238 (150 BKS.) (SH57.29-6-20.) MP 224388 ROLLS-ROYCE LTD. INSTRUCTIONS. To 19 Order No. WA {Mr Wallis} 105 (4) Customer's No. No7 It is considered that the minimum low speed sparking speeds should be ;- (a) Fully advanced 300 rpm (b) Central position 210 rpm (c) Fully retarded 190 rpm " " The results of the three magnetos are attached for reference Signed H.E.W. This Sheet must be filed on completion of the work. | ||