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).
Engine detonation tests in response to a complaint, particularly in hot weather conditions.
| Identifier | ExFiles\Box 109\5\ scan0136 | |
| Date | 24th April 1939 | |
| 664 Sg.{Arthur F. Sidgreaves - MD} from Rm.{William Robotham - Chief Engineer} Rm{William Robotham - Chief Engineer}6/R.24.4.39. WXA-1 Sg{Arthur F. Sidgreaves - MD}10/E21.4.39. A number of tests on detonation have been carried out since we received your complaint, but we are not yet in a position to issue a report. During the recent spell of hot dry weather, we have had detonation on cars that have been entirely free from this phenomenon. We have established that your car was no worse under these conditions than standard Wraiths in the Experimental. If we are to make a car which can never be made to detonate on the worst day in the year for atmospheric conditions, we shall have to lose a lot of performance. We think there is some difference between the R.R. distributor and the Delco, but we are not yet certain what this is. Rm.{William Robotham - Chief Engineer} | ||