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).
Recording the weights of four top-half crankcases.
| Identifier | ExFiles\Box 3\3\ 03-page019 | |
| Date | 5th July 1911 | |
| Section FDO 3400 V260 Re Weight of Crankcase 4 crank cases (top halves) weights as follows. 71 lbs. 72 " 72 " 72 " | ||