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).
Record of engine compression experiments conducted at various speeds on a chassis.
| Identifier | ExFiles\Box 19\7\ Scan042 | |
| Date | 3rd November 1910 | |
| R.R. 148 (20m) (P 548.10.10.10) G 1130. x490 Compression Experiments at various engine speeds. 4400 Engine speed 500 750 1000 1250 1500 1750 2000 2250 Compression lbs. 55 55 Too much vibration on engine to read gauge 55 54 51 49 Taken on P1400 type Chassis with RR pressure gauge. 0 to 140 + RR non-return valve. Engine about 70°C. Recd O 5/V R 3/11/10 | ||