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).
Drawing of smaller diameter inlet and exhaust valves for the Lighter Phantom Engine.
| Identifier | ExFiles\Box 17\6\ Scan017 | |
| Date | 27th October 1916 | |
| LIGHTER PHANTOM ENGINE - SMALLER DIAM VALVES - BOTH INLET & EXHAUST. 1.600 DIA RADIUS 1.750 DIA OOK 639/6 27.10.16 | ||