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).
Technical note comparing the weights and valve specifications of 1200 and 1400 type cylinders.
| Identifier | ExFiles\Box 3\3\ 03-page010 | |
| Date | 7th May 1910 | |
| 3400.X200 Weights. Weight of cylinders with valves and springs fitted. 1200 type - 106 lbs 1400 type - 95 " 1400 type valve ports have a much better lead out Also the outlet port is 3/16" larger diameter Valves stand 1/2" further out from cylr. bores 7-5-10 | ||