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 regarding misfiring issues with magneto ignition on Phantom II car cylinder heads, suggesting tests with CH3 and S1 plugs.
| Identifier | ExFiles\Box 162\6\ img146 | |
| Date | 2nd May 1932 | |
| Lodge Plugs Limited, Rugby. Telephone. 276 RUGBY (2 lines) Established 1904. Telegrams. 'LODGE, RUGBY' Handwritten notes: X4425, Chassis Messrs. Rolls-Royce, Limited, D E R B Y. Your Ref. Hs{Lord Ernest Hives - Chair}/Lid.{A. J. Lidsey}6/MA. Our Ref. AML/PB Date 2 May 1932. All letters must be addressed to the Company, not to individuals For the attention of Mr.A.J.Lidsey. Dear Sirs, We thank you for your letter of April 29th enclosing sections of the P.II car cylinder heads. We asked for these as we thought the misfiring at low speeds on magneto ignition might be due to the plugs being pocketed, but from your drawings we do not now think this is the explanation. However, as an experiment we are sending you 12 CH3 plugs having a reach of 3/4", and you might test if these show any improvement. Of the plugs you have tried we should have expected our S1 to be the most suitable, and reverting to your letter of April 25th we should like you to make sure that the report on the test of this plug is correct. You state that it is satisfactory at high speed but poor at low speed. In all the tests that we have made on various engines with this S1 plug we have always found it exceptionally good for slow speed running. The fault that we should anticipate you might find with this plug is too rapid burning of the points when used with magneto ignition owing to the knife edge form of spark gap. It may be that your experience of poor slow running with this S1 plug is due to the spark gap having already burnt too wide. We should, however, like you to give careful consideration to this plug as we think it should meet your requirements best of all. Yours faithfully, LODGE PLUGS LIMITED. [Signature] DIRECTOR. RECTORS: J.{Mr Johnson W.M.} ALFRED HOPPS BERNARD HOPPS ALEC. M.{Mr Moon / Mr Moore} LODGE F.{Mr Friese} BRODIE LODGE. | ||