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 valve lift against the engine crank angle.
| Identifier | ExFiles\Box 179\2\ img233 | |
| Date | 4th December 1925 guessed | |
| VALVE 0.100 0.075 0.050 0.025 100 120 140 160 180 B.D.C. 200 220 240 CRANK ANGLE (DEGREES) | ||