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).
Performance figures of a modified Wraith after fitting new pistons and a cylinder block.
| Identifier | ExFiles\Box 109\5\ scan0125 | |
| Date | 11th March 1939 | |
| 600 664 Sg.{Arthur F. Sidgreaves - MD} from Rm.{William Robotham - Chief Engineer} Hs.{Lord Ernest Hives - Chair} Ey. Mx.{John H Maddocks - Chief Proving Officer} Rm{William Robotham - Chief Engineer}14/R.11.3.39. IMPROVED WRAITH PERFORMANCE. see 600 Attached is a copy of figures obtained on your car before and after fitting the modifications enumerated in Rm.{William Robotham - Chief Engineer}8/MH.{M. Huckerby}8.2.39. The improvement obtained is not as great as that experienced on the Experimental car. On the other hand, new pistons and cylinder block were fitted, and, therefore, the engine is not yet entirely free. Generally speaking, we consider that the results achieved are representative of what may be expected from these modifications. Rm.{William Robotham - Chief Engineer} | ||