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 from the Ethyl Export Corporation regarding spark plug complaints on 3½ and 4¼ litre Bentley jobs, suspecting fuel types and cold induction.
| Identifier | ExFiles\Box 162\4\ img206 | |
| Date | 27th November 1936 | |
| 60016 CABLEGRAMS: ETHYLPORT. LONDON. TELEGRAMS: ETHYLPORT. SOWEST. WST ETHYL EXPORT CORPORATION Incorporated in the State of Delaware. U. S. A.{Mr Adams} with limited liability. THAMES HOUSE, MILLBANK LONDON, S.W.1 Telephone: VICTORIA 1441 Head Office: 135 EAST 42nd STREET NEW YORK. U.S.A 27th November, 1936. W. A.{Mr Adams} Robotham Esq., Experimental Department, Messrs. Rolls-Royce Ltd., Nightingale Road, DERBY. Dear Rm.{William Robotham - Chief Engineer}, Whilst in Paris this week I was able to see Slater, who took me out in a Bentley in which we fitted some defective K.L.G.850 plugs. He also showed me a list of complaints which they had received from several of your customers in France, both on 3½ and 4¼ litre jobs. He told me that they had had most of these complaints since the colder weather appeared, and I have asked him whether he would be good enough to let me know, if possible, what fuels were used by the various owners. He told me that only Azur and Esso were involved, but I wanted to know on which fuel they had the most complaints because Azur contains less lead than Esso. I have suggested to Slater that he runs two tests, one on his own car with K.L.G.850 plugs and using only Azur, and another test on a car with the same plugs employing only Esso. He will then be able to tell whether the fuel which has the most lead in it accelerates the trouble. If they get the trouble in a reasonable period, or unreasonable whichever way you like, I have suggested that they do similar tests using K.L.G.765a (old type) plugs and perhaps with one of the latest type Bosch plugs. They have already tried the Bosch type (W/145/1) which has so far been satisfactory, but apparently it has not done very much running. I am still of the opinion that this trouble is mainly due to a cold type of induction which involves considerable wetting of the plugs in the early stages of starting and warming up the engine. We did a small test at your shops in Paris and started the engine of a car which had been lying idle for a day or so, and then stopping it after about a minute's run. We removed one or two of the plugs and found that they were exceedingly wet right up inside the body. I am not saying that this proves anything particular, but it appears that the engine does run very cool because there is always a considerable | ||