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).
Cases of surface tracking on the moulded battery ignition rotor body.
| Identifier | WestWitteringFiles\Q\2-July1927-September1927\ 52 | |
| Date | 23th August 1927 | |
| To R.{Sir Henry Royce} from EFC. c. BJ. EY. c. Wor.{Arthur Wormald - General Works Manager} E.{Mr Elliott - Chief Engineer} MOULDED BATTERY IGNITION ROTOR BODY. X840 Three cases (reported to me) have now occurred on customers' chassis of surface tracking of the ignition rotor the last of which I sending you for inspection. We have had, I believe, two cases of this on experimental cars, but we have not attached so much importance to these owing to the abnormal ignition conditions which we may sometimes have used during experiments. Now that we have had three cases on customers' chassis, I feel that the matter should be reported to you. The sample sent to you is from a 40/50 chassis which has been in customer's hands 6 months. One feels that the initiation of the tracking must be due to moisture with some amount of acidity from the nitric acid in the fumes. Though I believe one of the cases we had had gone through the material to the spindle, due to a fault in all other cases this is not so, but the spark has been jumping from the tracked surface of the rotor body to metalwork in the contact breaker chamber, the nearest point being the insulated condenser connection bar. It would appear that the umbrella rotor which we have now under test in another connection may overcome this trouble. You will remember that a considerable time ago now I reported to you that when the output of the distributor was open circuited, we had made observations and shown that the safety spark did not go straight across from the rotor periphery to the metal of the contact breaker body, as intended, but Contd | ||