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 testing procedure detailing checks for gear meshing and minimum sparking speeds at various positions.
| Identifier | ExFiles\Box 70\4\ scan0136 | |
| Date | 3rd February 1928 guessed | |
| -3- Contd. be further observed whilst running the magneto that the meshing of the distributor gear wheel with the pinion is correct; incorrect meshing being indicated by an uneven rattle emanating from the distributor end of the magneto. also that the contact breaker noise is reasonable and that the armature is not fouling the pole shoes. (7) The slowest speeds at which regular sparking will occur on 5.5 mm. gaps in air shall now be ascertained and shall not exceed :- for (a) Fully advanced position 120 r.p.m. (b) Central position 160 r.p.m. (c) Fully retarded position 190 r.p.m. Note:- The minimum sparking speed for each of the three positions can be taken to be that speed at which 72 consecutive sparks, without missing, are given by the magneto at some time within a period not greater than 5 minutes. EFC. | ||