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 timing of the magneto break, cams, and distributor.
| Identifier | ExFiles\Box 48\2\ Scan446 | |
| Date | 29th March 1926 | |
| Contd. -3- EFC {E. Fowler Clarke - Electrical Engineer} 1/T29.3.26. timing, cams and distributor. Regarding the earliness of the present break, we agree with their argument that they have timed the magneto to break earlier and thereby get a better performance at slow speeds in the retarded position than in the advanced. We are, however, still of the opinion that the break might be somewhat later without appreciable loss in this direction and, together with the other modifications which we suggest, a gain on the whole. For one thing, the make is at present so early that even in retarded slow speed running there will be some current to be reversed before a current in the required direction is started up, and it is quite possible that an appreciable improvement would be obtained by making the make later as suggested. We do not quite appreciate their argument, for instance - "--- a spark always occurring in what is effectively a retarded position, even with the magneto running at high speed with the spark fully advanced, would result in excessive sparking between the platinum points and thus reduce the life of the points quite appreciably." The break in the advanced position is already so early that to make it even 15° later would not cause it to take place "in what is effectively a retarded position", particularly so at high speeds. They apparently imply that their intention is to overcome the trouble of excess | ||