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).
Diagram of a 20 HP long duration inlet valve lift, comparing it to the standard camshaft.
| Identifier | WestWitteringFiles\Q\2April1927-June1927\ 121 | |
| Date | 23th February 1927 guessed | |
| 20 H.P LONG DURATION INLET VALVE LIFT DIAGRAM THE DOTTED CURVE REFERS TO STANDARD CAMSHAFT VALVE LIFT .30 .20 .10 0 CRANKSHAFT MOVEMENT. 330° T.D.C. 30° 60° 90° 120° 150° 180° 210° 240° 270° | ||