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 regarding testing a modification to an armoured car's air pump and camshaft drive to reduce gear and valve noise.
| Identifier | WestWitteringFiles\I\October1922\ Scan5 | |
| Date | 28th October 1930 | |
| Roycar Dinf X4195 Hives Couple armoured car air pumps Direct To front end of cam shaft by steel or fabric joints Test if it causes Gear Noise by silencing air and Valve Noises Royces | ||