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).
Investigating engine roughness in Phantom III experimental cars related to its dual ignition system.
| Identifier | ExFiles\Box 91\1\ scan0534 | |
| Date | 22th February 1938 | |
| 300. Rm{William Robotham - Chief Engineer}/FD.{Frank Dodd - Bodies} from Rm.{William Robotham - Chief Engineer} Rm{William Robotham - Chief Engineer}2/R.22.2.38. P.III SMOOTHNESS. We have repeatedly noticed that our P.III experimental cars seem to be rougher on one ignition than on the other. We should like you to confirm whether this is due to difference in timing between the two ignitions, or whether when they are timed to give the same performance, one gives a smoother engine than the other. We should also like you to find out whether either of them can be retarded slightly to give a sweeter engine without losing performance. The main object of this is to give us information for dispensing with one set of plugs on the P.III, which we are proposing to do in the near future. Rm.{William Robotham - Chief Engineer} | ||