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).
Using a Bentley instrument board on the Vulture chassis, requesting specifications for the speedometer and tachometer.
| Identifier | ExFiles\Box 123\3\ scan0060 | |
| Date | 5th December 1933 | |
| Rm{William Robotham - Chief Engineer} N4704 To Hs.{Lord Ernest Hives - Chair} from EV.{Ivan Evernden - coachwork} EV.{Ivan Evernden - coachwork}2/HP.5.12.33 c.c. E.E. Da.{Bernard Day - Chassis Design} Vulture Instrument Board. We wish to confirm that it is agreedto use the Bentley instrument board on the first Vulture chassis. We propose to treat this in such a way that the fact that it is Bentley will not be recognised. The whole face of the board will be in wood and only the dials of the instrument will show. A scheme is being produced shortly. In the meantime we think we should put on order a speedometer and tachometer and we wish to know the following facts before we do so:- (1) What is the axle ratio which will be used, 12/35 or 13/35. [Handwritten above: 2.92 2.700] (2) What is the speedometer drive ratio in the gearbox, that is to say, we want to know finally the ratio between the revolutions of the speedometer and the revolutions of the road wheels. (3) What is the exact rolling radius of the tyres. (4) In connection with the tachometer, what is the ratio of the drive to the engine revs. We understand that the speedometer should read to 110 miles an hour, and presume that the tachometer should read to 4000 revs. EV.{Ivan Evernden - coachwork} | ||