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 concerning the testing and comparison of different sparking plugs.
| Identifier | ExFiles\Box 58\2\ Scan103 | |
| Date | 31th May 1934 | |
| 81912a Hs{Lord Ernest Hives - Chair}/Wst.8/MA. 31st May, 1934. Messrs. K.L.G. Sparking Plugs Ltd., Robinhood Engineering Works, Putney Vale, London, S.W.15. For the attention of Major C.M. Carington. Dear Sir, Referring to your letter of the 30th instant reference CMC/MEN. we already have a sectioned sample C.F. Sparking Plug at our Works which we should be pleased to show you. With regard to the sample sparking plug you sent to us with the bar form of earth electrode we have carried out voltage tests on this and we find that the voltage is in excess, as expected, of the standard 744 sparking plug. The other plug you sent of the "Wizard" type construction has a less operating voltage than the 744 and would appear to be a very promising type of sparking plug, all these plugs are now in an engine for test. With regard to the 821 & 822 sparking plug if you are interested we would test 12 of each out on a full engine in order to gain an accurate comparison of electrode erosion. As you no doubt realise results on other engines offer no criterion to results we may obtain on our own engines. We have taken voltage breakdown curves of all three plugs, i.e. 744, 821 & 822 plotted against pressure and the next time you are at the Works we will show you these curves and discuss the results. Yours faithfully, FOR ROLLS-ROYCE LIMITED. | ||