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).
Specifications for speedometer and rev-counter calibration, performance, and required cable length.
| Identifier | ExFiles\Box 67a\2\ scan0078 | |
| Date | 20th December 1927 guessed | |
| contd :- -2- the above specification holds good. The speedometers required, as also the rev. counters, should be set to read correctly at 25°C, and for 16-tooth axles should read 88.5 m.p.h. at 1000 speedometer r.p.m., for 17-tooth axles 94 MPH. at 1000 speedometer RPM. These may be about 2% faster than our present production standard but we want to make certain our sports car speedometers do not read slow. All speedometers and rev. counters should, of course, be fitted with the latest A.T. compensating disc which reduces the temperature error to 2%. The length of speedometer cable required is 4' 10". Hs{Lord Ernest Hives - Chair}/Rn{Mr Robinson} | ||