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).
Test results for a magneto, detailing spark gap data, low-speed sparking performance, and a noise comparison.
| Identifier | ExFiles\Box 48\2\ Scan143 | |
| Date | 29th June 1920 | |
| RR 238 (150 BKS.) (BH57.29-6-20.) MP 224358 ROLLS-ROYCE LTD. INSTRUCTIONS. To ________________________ 19 Order No. W.A.64 (4) Customer's No. __________ a 10.2 mm b. 4.3 mm c. 2.0 mm d. {John DeLooze - Company Secretary} .5 mm. with chemical leak and annular gap. Magneto will not spark at gap at any speed (leak at 20°C) VII Low speed sparking a. {Mr Adams} Fully advanced 245 rpm b. Central position 300 rpm c. Fully retarded 385 rpm. (Hand range only). These machines are noticeably quieter than the Watford E.D.6. the gear noise being practically nil and the contact breaker noise considerably muffled in spite of two ventilating holes in cover. Signed H.E.W. This Sheet must be filed on completion of the work. | ||