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).
Test report on a Scintilla magneto, detailing performance characteristics and its allocation to chassis 93-MX.
| Identifier | WestWitteringFiles\L\July1924-September1924\ Scan55 | |
| Date | 4th September 1924 | |
| Contd. -2- EFC2/T4.9.24. (8) On the open circuit test, there is a tendency for the discharge to take place at places other than the safety gap. This feature is common to all the Scintilla magnetos which we have tested. A reduction in the safety gap to overcome this would probably be allowable, still keeping within the requirements of our specification. (9)&(10) The open circuit volt-speed characteristic of the primary winding is similar to that for the smaller machine, and the short circuit amper-speed curve is similar, but shows about 20% more current. (11) Utility tests. The results of these tests are similar to those obtained on the smaller machine, i.e. capability of sparking leaky gaps appears to be not so good as the more ordinary types of magneto, though on a well insulated gap the spark obtainable is longer. (12) The high speed sparking characteristics are satisfactory, as on all other Scintilla magnetos tested. (13) The lowest speeds at which regular sparking occurs on 5.5 mm. gaps for (b) fully advanced position (hand range) and (c) fully retarded position, are 160 r.p.m. and 290 r.p.m. respectively, showing an appreciable loss of performance due to the retard. (14) Silence of operation. The machine was fairly reasonably quiet. This machine has now been handed over to the shop to be fitted to the new engine for chassis 93-MX.{John H Maddocks - Chief Proving Officer} EFC. | ||