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).
The failure of an in-house ignition coil on the Wraith model, the decision to fit Delco coils, and a related oil consumption issue.
| Identifier | ExFiles\Box 164\5\ img442 | |
| Date | 9th May 1938 | |
| bo2o . Coil. BY/ID. c. Rm.{William Robotham - Chief Engineer} c. Da.{Bernard Day - Chassis Design} c. RMO. c. ROY{Sir Henry Royce} BY.2/G.9.5.38. Jlec CHILDS 6017 WRAITH - IGNITION COIL. It was my intention to use the RR. design of coil for the first 100 cars, with the object of maintaining the tradition of making our own ignition equipment. Unfortunately, however, on Sg{Arthur F. Sidgreaves - MD}'s car the RR. coil has failed to maintain slow running conditions. By replacing the RR. with the Delco the slow running was immediately recovered, the evidence being quite clear that it was lack of voltage on the RR. coil which was the essential factor. In view of these facts, therefore, we will have to fit Delco on the first 100 cars (Wraith). In the meantime we are producing another coil with more capacity, following our present lines, and in addition a metal case coil. We produced one of these some years ago, but it appeared to die a natural death. It is important, however, that we should make the two further coils referred to, as I am desirous of maintaining RR. ignition equipment on the RR. line of cars. The oil consumption on Sg{Arthur F. Sidgreaves - MD}'s car where the trouble occurred was between 2000/3000 miles to the gallon, so that it is not a over-oiling problem but purely one resulting from increased resistance due to the presence of a thin film of oil accumulating when the engine is cold or idling, the voltage not being sufficient to burn off the points the accumulated carbon causing increased resistance. BY.{R.W. Bailey - Chief Engineer} By | ||