Blueprint of a 25 HP crankcase (inverted top half) showing the setup for measuring main bearing deflection.
| Identifier | ExFiles\Box 103\2\ scan0229 | |
| Date | 20th January 1931 guessed | |
| CRANKCASE 25 H.P. (INVERTED TOP HALF) SUPPORT INDICATOR CLOCK ON CENTRE MAIN BEARING. SUPPORT. | ||
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).