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 valve rocker showing the arms drilled.
| Identifier | ExFiles\Box 33\2\ Scan019 | |
| Date | 6th June 1916 | |
| VALVE ROCKER E9813 SHOWING ARMS DRILLED ROLLS-ROYCE L. DERBY DRAWING OFFICE 6 JUN. 1916 D.L.A. 6.6.16 | ||