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).
The performance and noise reduction of an altered magneto, following an assistant's test.
| Identifier | ExFiles\Box 48\2\ Scan299 | |
| Date | 8th July 1925 | |
| Contd. -2- EFC {E. Fowler Clarke - Electrical Engineer} 10/T8.7.25. As regards the object ofthis alteration, e.g. the reduction of noisiness of the magneto, the following is quoted from my assistant's report on the test of this machine :- " The noise emanating from this magneto is considered to be quite reasonable, the sleeves being noticeably quieter at all speeds, the flopping being less violent and less pronounced. This quietness of the sleeves is considered to be due to the better fitting of the sleeves and the reduction of the magnetic effect caused by a larger air gap. The cam ring works much more smoothly and requires less effort to move it tangentially, than on the standard machines. The general performance of this magneto is considered to be good, the only material difference from to the standard being in the low speed sparking which is even now considered to be quite reasonable. The improvement this feature effects on the mechanical performance of the magneto is very advantageous, the detrimental effect on the electrical performance being very slight." In view of the above it is considered definitely advisable to have further magnetos made up in this way. Accordingly in another note we have asked for Nos.73970/2 to be modified to this condition. Presumably this alteration can be effected quite readily on present standard magnetos, especially upon those which already have the better location of the sleeve and with that in mind we would, upon return of Nos.73970/2, ask for two more magnetos (which these two will replace on chassis) to be altered in the same way. | ||