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).
Graph plotting the variation of maximum ball pin load against axle velocity for a 7.5' lever.
| Identifier | WestWitteringFiles\V\December1930-February1931\ Scan205 | |
| Date | 9th January 1931 guessed | |
| SHEET VII VARIATION OF BALL PIN LOAD WITH AXLE VELOCITY 7.5" LEVER VALVES 2G. G4 MAXIMUM BALL PIN LOAD 500 400 LONG STROKES HIGH PRESSURE 300 200 SHORT STROKES HIGH PRESSURE 100 LONG & SHORT STROKES LOW PRESSURE 0 AXLE VELOCITY 7.5" LEVER FT/SEC | ||