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).
Telegram advising the despatch of special pistons with instructions to raise the compression ratio.
| Identifier | ExFiles\Box 146\5\ scan0174 | |
| Date | 20th June 1939 | |
| 1245 20.6.39. SLEATOR, FRANCOBRIT 86. SPECIAL PISTONS DESPATCHED TODAY STOP RAISE COMPRESSION BY HALF RATIO. ROYCAR. | ||