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 Scintilla, Watford, and Conner magnetos regarding slow-speed sparking performance and the formulation of a new specification.
| Identifier | Morton\M20.3\ img007 | |
| Date | 26th May 1924 | |
| Contd. -2- EFC2/T26.5.24. In one respect the Scintilla magneto is short of an important feature which is possessed by the Watford E.O.6. We refer to the fact that owing to the use of the movable sleeve it is possible to get slow speed sparking characteristics in the retarded position which are quite as good and even better than those in the advanced position, whereas in magnetos without the sleeve (or some equivalent arrangement such as was possessed by the Conner magneto which we tested, namely, the copper pole piece embedded damping conductor) this is not usually the case. In the Scintilla case under consideration at the moment, the slow speed sparking characteristics for the retard position are definitely inferior to those for the advance, and also those of the Watford E.O.6. A general specification of required performance of magneto for 40/50 car covering all points is being formulated, based mainly upon observations of performance of present standard Watford E.O.6 magnetos and Scintilla AM-6-A magnetos with automatic advance. The M.L. and Lucas Cos' in addition to the Watford Co. are being approached as to the possibility of their submitting magnetos to meet this specification. EFC. | ||