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 unsatisfactory performance of platinum points on the Watford E.W.6. magneto.
| Identifier | WestWitteringFiles\T\2January1929-June1929\ Scan261 | |
| Date | 4th June 1929 | |
| R.{Sir Henry Royce} from EFC/HEW c. Sg.{Arthur F. Sidgreaves - MD} c. BY.{R.W. Bailey - Chief Engineer} Wor.{Arthur Wormald - General Works Manager} EFC is absent EFC/HEW1/ADL4.6.29. X.7791. WATFORD E.W.6. MAGNETO. We are not satisfied with the performance of the platinum points on the Watford E.W.6 magneto. Several contact breakers on experimental chassis have been re-fitted with new platinum points after only a relatively small mileage, owing to the rapid burning away of these points. Upon taking up this matter with Messrs. Norths, they stated that in their opinion the trouble was due to ingress of oil or petrol vapour. An examination of the faulty contact breakers however, did not strongly evidence the presence of oil film, and a Laboratory examination of the black deposit revealed a large proportion of platinum oxide with only a trace of carbon. Also the phenomenon does not occur consistently on all magnetos as would be the case if the trouble was due to outside effects, so that we consider the evidence to support Messrs. North's explanation is not sufficient. At Messrs. North's request we have fitted new contact breaker covers to our experimental magnetos with a system of ventilation incorporated, and they are hopeful that this will cure the trouble. We will carefully watch the platinum points on these magnetos and report further. contd. | ||