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).
Maintenance schedule and replacement policy for tungsten battery ignition contact points.
| Identifier | ExFiles\Box 61b\1\ scan0075 | |
| Date | 3rd March 1930 | |
| By from EFC. c. Ry/NHW. c. EP.{G. Eric Platford - Chief Quality Engineer} c. Hm.{Capt. W. Hallam - Head Repairs} X2894. EFC1/AD3.3.30. X.2894. TUNGSTEN BATTERY IGNITION CONTACT POINTS. QUESTION OF SPARES AND TOUCHING UP. It is now our impression from observation of the condition of tungsten battery ignition contact points on experimental cars over a considerable period, that these points will run at least 10,000 miles before trimming is necessary, but it is advisable to clean the surfaces and re-adjust the contact gap say every 5,000 miles to obtain and ensure immunity from misfires. We have noted in our actual experience, that provided the contact point surfaces are correctly bedded and lined up initially, 20,000 miles running without trimming is possible. Apparently it is very important for the points to be carefully lined up and carefully centrally bedded, (as we have instructed in the production specification of the unit) because otherwise a lip forms on the edge of the points and almost inevitably leads to irregular ignition. This state of affairs we fear would happen if we allowed customers to fit their own replacement points. We still recommend, as in our EFC2/T18.7.28 that to enable customers to clean these points when necessary we should include in the kit a small piece of flat carborundum which should be duly mentioned in the Instruction Book, at the same time making it clear that normally no touching up should be required over a long period of running. We further recommend that say after 10,000 miles, or whenever cars are in for repair, these tungsten points be not merely cleaned but properly re-bedded by our own repair staff, when possible. The necessity of really correct meeting of the flat surfaces of these tungsten points cannot be too strongly emphasised, and we recommend at this point that further instructions to this effect to the various repair depots be again circulated. | ||