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).
Four indicator diagrams comparing performance with and without a valve damping cylinder and at different valve overlap settings.
| Identifier | ExFiles\Box 105\3\ scan0336 | |
| Date | 24th February 1933 guessed | |
| Top Left Quadrant: J III REAR. 90 LB L.P. LOAD. HIGH PRESSURE NS{Norman Scott} 3670 HDY.{William Hardy} VALVE. OVERLAP + .015 WITH VALVE DAMPING CYLINDER 1" STROKE R.P.M 540 360 180 90 308 LB/D" = 133 LBS 120" IS 27/4/33 Top Right Quadrant: J III REAR. 90 LBS L.P. LOAD. HIGH PRESSURE NS{Norman Scott} 3670 HDY{William Hardy} VALVE. OVERLAP NIL WITH VALVE DAMPING CYLINDER. 1" STROKE R.P.M. 540 360 180 90 308 LB/D" = 133 LBS 120" IS 27/4/33 Bottom Left Quadrant: J III REAR. 90 LB L.P. LOAD. HIGH PRESSURE NS{Norman Scott} 3670 HDY.{William Hardy} VALVE. OVERLAD -- .015 WITH VALVE DAMPING CYLINDER 1" STROKE RPH 540 360 180 90 308 LB/D" = 133 LBS 120" IS 27/4/33 Bottom Right Quadrant: J III REAR. 90 LB L.P. LOAD. HIGH PRESSURE. NS{Norman Scott} 3670 HDY{William Hardy} VALVE, + .015" OVERLAP WITHOUT VALVE DAMPING CYLINDER 1" STROKE - NOISY R.P.M 540 360 180 90 308 LB/D" 133 LB 120" IS 26/4/33 | ||