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 graph for the 40/50 Chassis Engine, plotting various metrics against Revolutions Per Minute.
| Identifier | Morton\M22\ img079 | |
| Date | 5th May 1921 guessed | |
| 40/50 CHASSIS ENGINE REVS: PER MIN: 500 750 1000 1250 20 30 40 50 60 70 80 90 | ||