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).
Removing an inner spring from the oil ignition relay due to a reduction in magneto sleeve friction.
| Identifier | ExFiles\Box 65\1\ scan0121 | |
| Date | 12th February 1926 | |
| To Hs.{Lord Ernest Hives - Chair} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} X8685 Hs{Lord Ernest Hives - Chair}/Rml/LG12.2.26. OIL IGNITION RELAY. When the oil ignition relay was put into production initially, the positive limit for the friction on the magneto sleeve was 5 lbs. This necessitated having 2 return springs in the top of the relay to enable the hand control to function satisfactorily. The frictional limit on the magneto sleeve has now been reduced to a plus-limit of 3 lbs. It is therefore no longer necessary to have 2 return springs in the relay, and the inner spring can be deleted. We consider that this should be done at the earliest possible moment as from our recent tests we find that when cup leathers have been in service for a long time, their efficiency falls considerably and as the relay, in any case, only just functions satisfactorily with the present oil pressure, cars are likely to be running about with too little ignition advance. In addition, in the case of cars which come in for repair, the magneto friction should be tested and if this is less than 3 lbs., the inner springs should be removed from these cars. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||