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).
Comparison of low sparking speeds and bench test results for various magnetos, including Watford, Conner, and Bosch types.
| Identifier | ExFiles\Box 48\3\ Scan093 | |
| Date | 31th March 1921 | |
| To R & E. {Mr Elliott - Chief Engineer} from EFC. {E. Fowler Clarke - Electrical Engineer} Contd. -2- EFCB/T31.3.21. position than in the advanced, the 34° range was selected from the more retarded portion of the makers range instead of from the more advanced portion, this being the result of peculiarities of the design of these two magnetos, which peculiarities have already been mentioned. For the purpose of the R.R. car, a direct comparison of low sparking speed is here given. It will be seen how the E.O.6 type Watford magnetos and the Conner magneto, both of which have the above mentioned peculiarities of design, give the lowest sparking speeds. These are closely run by the Dixie Aero 648. Results for the R. {Sir Henry Royce} Bosch and U.S.A. Bosch may be compared with those given in our EFC {E. Fowler Clarke - Electrical Engineer} 4/T3.2.21 and show an improvement in the case of the U.S.A. Bosch due to the selection of the 34° range. Further, the present figures may be looked upon as being somewhat more reliable. In addition to the table on which only the low speed sparking results are given for each magneto, we attach a table of complete results of bench tests of the same magnetos. We have Mr. Royce's note R {Sir Henry Royce} /G24.3.21 and further work will be conducted as there suggested. EFC. {E. Fowler Clarke - Electrical Engineer} | ||