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).
Inspection of a mushroom type ignition rotor after a 10,000-mile bench test.
| Identifier | WestWitteringFiles\S\June1928-August1928\ Scan033 | |
| Date | 19th June 1928 | |
| To R.{Sir Henry Royce} from EFC. c. BJ. c. E.{Mr Elliott - Chief Engineer} c. EV.{Ivan Evernden - coachwork} MUSHROOM TYPE IGNITION ROTOR. We are sending for your inspection a rotor of the above type which has been subjected to an open circuit 10,000 mile bench test. (Distributor head in place but no distributing H.T. wires connected). Subsequently satisfactory operation of this rotor has been confirmed on normal test and by running on an experimental car. It should be observed that the grooves in the rotor periphery are not a result of tracking in the usual sense of the word, but are due to the disruptive action of the spark in the vicinity of its passage. In the case of a track, the H.T. current passes through the material, but in the present case has remained as a spark and has not actually got a hold in the material. EFC. | ||