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 Lodge Plugs Ltd. discussing the failure of returned spark plugs and recommending alternative models.
| Identifier | ExFiles\Box 162\6\ img128 | |
| Date | 7th April 1932 | |
| Telephone. 276 RUGBY (2 lines) Established 1904. Telegrams,"LODGE, RUGBY" 84425. Lodge Plugs Limited, Rugby. Messrs. Rolls-Royce Ltd., DERBY. HP Your Ref. Hs{Lord Ernest Hives - Chair}/Lid.{A. J. Lidsey}5/MA. Our Ref. BH/EW. Date 7 April 1932. All letters must be addressed to the Company, not to individuals For the attention of Mr. Lidsey. Dear Sirs, In reference to your letter of the 16th ult. relative to the three Model S1. plugs returned as defective, as a result of our examination of these we find that in the case of two of the plugs the insulators are slightly cracked, which would cause the condition that you complain of. We find the insulator of the third plug to be quite sound and are at a loss to understand why this should have failed, although we noticed there was a deposit of what appeared to be lead on the surface of the insulator, which may have caused partial failure, although we are inclined to think that there was not sufficient lead to account for this. We are interested to learn that these plugs have been found satisfactory in your standard compression engines. For your high compression engines with ratios above 5 to 1, we should recommend our Model C3. plug which you are already using. These C3. plugs are of mica construction and will withstand the heat of the higher compression engines without risk of deterioration of the insulator. It would probably be found that for normal touring conditions in the hands of the average user that the S1. plug would be satisfactory, even for the higher compression engines, and the S1. plug has the advantage of giving slightly better slow running performance. The writer has used a set of S1. plugs in his 25 h.p. Rolls for over 10,000 (Continued) [Left Margin Text] DIRECTORS: J.{Mr Johnson W.M.} ALFRED HOPPS. BERNARD HOPPS. ALEC M.{Mr Moon / Mr Moore} LODGE. F.{Mr Friese} BRODIE LODGE. | ||