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 to the Royal Aircraft Establishment regarding sparking plug testing and the effects of leaded fuel.
| Identifier | ExFiles\Box 58\2\ Scan066 | |
| Date | 13th December 1933 | |
| 81812a. Hs {Lord Ernest Hives - Chair} /Wst.4/MA. 13th December, 1933. Dr.G.F.Bairsto, Royal Aircraft Establishment, South Farnborough, HANTS. Dear Bairsto, In reading through a report from your Dept., on sparking plugs I notice reference to a specification No.EE.341 to which test these plugs were submitted. We have a test here which I have instituted for sparking plugs removed from time to time off Development engines and which test consists of, first dismantling the plug and testing the central electrode separately on a high tension transformer, and secondly testing the completed plug under pressure for sparking etc. I should be interested to have a copy of the above specification in order that I may satisfy myself that the tests we carry out here approximate to the test conditions imposed on sparking plugs at the R.A.E. We are having quite an interesting time trying to get sparking plugs to stand up to the effects of tetra ethyl lead in the fuels which we are now using. The best material we have found so far for the central electrode is No.10 grade stellite but even this is attacked considerably by the lead oxide. We have also found that the mica is considerably attacked by the lead, and I should be glad to have your opinion regarding the relative merits of Ceramic Insulators and Mica Insulators in respect to the lead oxide attack. | ||