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).
Cause of engine detonation and suggesting a diagnostic experiment.
| Identifier | ExFiles\Box 109\5\ scan0139 | |
| Date | 11th July 1939 | |
| 66H W/S. To Sg.{Arthur F. Sidgreaves - MD} from Rm.{William Robotham - Chief Engineer} Rm.{William Robotham - Chief Engineer}6/MH.{M. Huckerby}11.7.39. WMB.11. Replying to Sg.{Arthur F. Sidgreaves - MD}3/E.11.7.39, I am wondering whether the detonation you are experiencing on this car can possibly be due to a timing gear rattle which is gradually developing. This sounds very like detonation as it only comes in at full throttle. A simple experiment to prove the point would be to empty the tank and run on Cleveland Discol. It is quite certain that the engine will not detonate on Cleveland Discol. In any case you will want the noise removing, but you might like to stick to the modified parts if it was found that the noise was due to timing gear rattle. Rm.{William Robotham - Chief Engineer} | ||