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).
Recommending fitting flush top pistons to a 7:1 C/R head to reduce detonation.
| Identifier | ExFiles\Box 148\1\ scan0203 | |
| Date | 6th November 1939 | |
| 1256 To Rm{William Robotham - Chief Engineer}/Wym.{G. Harold Whyman - Experimental Manager} from Rm.{William Robotham - Chief Engineer} Rm.{William Robotham - Chief Engineer}3/MH.{M. Huckerby}6.11.39. Before you finish with the 7 : 1 C/R head you should try a set of flush top pistons (if these are not already fitted) as these reduce detonation. Rm.{William Robotham - Chief Engineer} | ||