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).
Specifications for inlet and exhaust valves for a Phantom III 4-port head.
| Identifier | ExFiles\Box 93\4\ scan0021 | |
| Date | 8th October 1935 | |
| To E: +319 Hs{Lord Ernest Hives - Chair}/Smth.3/KW. 8.10.35. Phantom III. 4-port Head. Further to our memo. Hs{Lord Ernest Hives - Chair}/Smth.21/KW.2.10.35, in our opinion it will be sufficient to provide for a 1.500 inlet valve and 1.300 exhaust valve, if diameters larger than this will entail considerable modifications, such as moving studs and water passages. Hs{Lord Ernest Hives - Chair}/Smth. | ||