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 for testing the sparking characteristics and performance of a magneto.
| Identifier | ExFiles\Box 4\5\ 05-page138 | |
| Date | 3rd February 1921 guessed | |
| -4- Contd. contact breaker lever advanced until the maximum sparking advance is found. NOTE:- The maximum sparking advance can be taken to be that advance at which 100 sparks, without missing, are given by the magneto at some time within a period not greater than 5 minutes. A mark shall be made to indicate this advance after the machine has been stopped. The contact breaker lever shall now be retarded 34° making use of the disc fitted to the spindle, used in (6). (15) The magneto shall again be run at high speed and the high speed sparking characteristics shall be obtained. Remarks should be made as to at what speeds and under what circumstances the magneto fails to spark, and in particular the effect of flux distortion shall be noted from the unequal character of the sparks from the two sides of the magneto, if such a difference obtains. (16) The low speed sparking characteristics of the magneto shall now be obtained, with distributor connected up as before to 5.5 mm. gaps. The slowest speeds at which regular sparking shall occur with - (a) Fully advanced position. (b) Central position. and (c) Fully retarded position. (such positions corresponding to the range obtained above) shall be ascertained. Contd. | ||