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).
Confirming the fitting of raised crown pistons to a Wraith chassis to increase compression.
| Identifier | ExFiles\Box 146\5\ scan0255 | |
| Date | 30th January 1940 | |
| 1245 To "Rm{William Robotham - Chief Engineer}" Derby c. to Rm{William Robotham - Chief Engineer}/CTS.{C. Trot Salt - Carburation} Levallois Sr/VA3/MLG.30.I.40 Re- Fitting raised crown pistons to Wraith chassis to increase the compression (Rm{William Robotham - Chief Engineer}/CTS.{C. Trot Salt - Carburation}IO/JH.24.6.38) We have fitted a set of the above type of pistons to the undermentioned chassis :- Chassis N° - Owner - Engine N° - Type of piston fitted -Mileage when fitted - Date when fitted WXA-86 - Mr.Schwob d'Hericourt - U.6.W.L. - EB-4757 (raised crown) - 9.897 kms - 30.10.39 (aerolite high compression ) (Compression raised by one ratio) "VA" | ||