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).
Specifying the speedometer calibration for the 12-EX chassis.
| Identifier | ExFiles\Box 66\4\ scan0250 | |
| Date | 22th March 1928 | |
| X8310 EFC. 22.3.28. SPEEDOMETER FOR 12-EX. X4308 X8310 The speedometer drive gearing on this particular chassis gives 736.6 speedometer drive R.P.M. at 60 m.p.h. i.e. on your test rig running at 600 r.p.m., the speedometer to be correct must read 48.9 m.p.h. A.J.Lidsey. | ||