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).
Note on testing balance weights fitted to a crankshaft.
| Identifier | ExFiles\Box 25\3\ Scan012 | |
| Date | 2nd February 1911 | |
| R.R. 148 (20 R) (P 548.10.10.10) G-1130. Engine X634 . 1/2/11 Balance weights to crank-shaft 4100 Fitted to 1649 chassis 24 1/2" capacity slipper wheel solid crank pinion. There was no noticeable difference, if anything they brought on slight crank-shaft vibrations. Magneto drive broke when they were being tested. C.P 2/2/11 | ||