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 design and performance variations of six magnetos, focusing on distributor rotor location and internal timing.
| Identifier | ExFiles\Box 40\2\ Scan243 | |
| Date | 11th February 1928 | |
| EFCl/T11.2.28. -5- Contd. A point we have noted on these six magnetos is that the angular location of the distributor rotor is now made by means of a stud let into the bakelite wheel engaging a hole in the body of the rotor. The earlier few machines of this type incorporated the horseshoe method of location and we had understood Mr. North to make a great point of the superiority of this method in previous conversation. we have therefore taken up the matter with them so as to ask the reason for the change. In regard to electrical performance, generally speaking these magnetos satisfy our specification pretty well, but we have noticed considerable variation in the internal timing of the magnetos both amongst themselves and in some cases considerable departure from the timing which we think is correct on principle. This appears to be the reason for some amount of variation in the low speed retarded performance. In some cases the machines do not meet our low speed performance requirements. We have received no complaint of faulty low speed performance on the car though there has not been much opportunity so far of properly trying this out. The results received from Mr. Ellis of low speed sparking corroborate our remarks on this feature which remarks have applied to the magnetos passed to our Dept. It should perhaps have been stated Contd. that it was the first three of the earlier number of machines received that passed our production test electrically, two of which are on 14-EX and 15-EX respectively. Three later ones | ||