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).
Request to remove existing P.450 pistons and fit new P.446 pistons on a Wraith III No.4 Unit for a test.
| Identifier | ExFiles\Box 9\1\ 01-page23 | |
| Date | 24th April 1939 | |
| 636 To HPC. Rm{William Robotham - Chief Engineer}/CTS.{C. Trot Salt - Carburation}8/JH.24.4.39. Piston Test. Wraith III No.4. Unit. Will you please remove the existing pistons P.450 from the above unit and fit - 6 new pistons P.446 (standard TC.15). The engine is in No.30 Test House. Rm{William Robotham - Chief Engineer}/CTS.{C. Trot Salt - Carburation} | ||