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 Delco Remy & Hyatt Ltd. regarding ignition coil temperature tests and a request for a service guarantee.
| Identifier | ExFiles\Box 164\5\ img341 | |
| Date | 5th May 1938 | |
| 6119 Rm{William Robotham - Chief Engineer}/RC.{R. Childs}11/JH. 5th May, 1938. Messrs.Delco Remy & Hyatt Ltd., 111, Grosvenor Road, LONDON.S.W.1. For the attention of W.O. Kennington Esq. Dear Sirs, We have just completed a series of tests on various ignition coils with regard to running temperatures when in normal use. We find that with an under bonnet temperature of about 45°C your coil has a primary winding temperature of 96°C after an hours run which is appreciably higher than the other types tried. Would you consider this temperature satisfactory? Also would you be prepared to guarantee this coil for two years service, working under these conditions? up to date we have had very good service from this coil, but we are a little worried as to the effects of the high running temperature, which we consider would easily top the 100°C mark in hot weather. We should much appreciate your comments on this matter. We are returning under separate cover three distributors to Dw.291 for complete overhaul and renewal where necessary; at the same time we should like the governor characteristic in each case altering to the following limits:- NOTE for our reference. Rm{William Robotham - Chief Engineer}/RC.{R. Childs} ( At this period it had been decided that the RR. Coil should run in conjunction with the RR. Distributor, which has a make Ratio of .55 against Cont'le .75 of the Delco Unit. Thus we must expect still higher temperatures when using the Delco. Distrib.) | ||