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).
Letter providing feedback on the testing of spark plugs Nos. 105-106 sent by The Robinhood Engineering Works.
| Identifier | ExFiles\Box 58\3\ Scan027 | |
| Date | 13th November 1919 | |
| X.1918 l. EH9/LG13.11.19. 13th. Nov. 1919. The Robinhood Engineering Works, Putney Valve, London S.W.15. Dear Sirs, With reference to the plugs Nos.105-106 which you sent for us to try. We have tested some of these on the road and find that they are an improvement over the E4 type of plug as regards internal leakage due to soot or carbon. We have not yet, however, had sufficient time to be able to say that they are entirely satisfactory. We noticed on one of the No.106 type of plug which we had run, that after running full power, the spark gaps had altered; the centre electrode appeared to have moved over to one side. We are continuing our tests and will let you know more as soon as possible. Yours faithfully, [Footer text, upside down]: R.R. 233 A (100) 8-18 (T) 575. 16-1-19 G 233T | ||