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).
Magneto noise and operating force issues, suggesting design modifications and referencing various suppliers and models.
| Identifier | ExFiles\Box 40\2\ Scan242 | |
| Date | 11th February 1928 | |
| EPC1/T11.2.28. -2- Contd. to his satisfaction. When a particularly quiet machine is wanted for some special purpose, one of our Lucas machines is asked for. It has been suggested that Messrs. North ought to try :- (1) Redesigning their lever and cams on the lines of the Lucas, or (2) Eliminating the lever altogether and making a pivotless machine as made by Marelli and in certain U.S.A. makes. The position in regard to contact breaker noise on these machines appears to be much the same as that with the EO6 type over which there has been considerable difficulty. Regarding the tangential force to operate the lever, we have noted the remarks contained in your R4/M2.2.28. The same thing happened with the EW6 machine which we allotted to Sports car 17-EX. The testers had to remove this to ease the cam ring. We had given Messrs. North the necessary specifica- tion that the tangential force must not exceed 2 lbs. wt., but had ourselves noted that in one or two of these machines this force had been exceeded, in some cases throughout the complete range and in some cases it was irregular over the range. This has been carefully pointed out to them and your note, which arrived while the subject was under discussion with them, was shown to Mr. North. The nine magnetos at present with Mr. Ellis have not yet been tried for noise, but according to their report, the operating tangential force for two of these machines exceeds our limit. Contd. | ||