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).
Performance test report for the 10-EX car at Brooklands, comparing it to a standard 40/50 touring car.
| Identifier | WestWitteringFiles\Q\2-July1927-September1927\ 81 | |
| Date | 6th September 1927 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. to BJ. Wor.{Arthur Wormald - General Works Manager} c. to RG.{Mr Rowledge} E.{Mr Elliott - Chief Engineer} c. to DA.{Bernard Day - Chassis Design} BY.{R.W. Bailey - Chief Engineer} c. to OY. EP.{G. Eric Platford - Chief Quality Engineer} c. to MX.{John H Maddocks - Chief Proving Officer} Hm.{Capt. W. Hallam - Head Repairs} ORIGINAL Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}/LG6.9.27. [Handwritten numbers in box] X8774 X877 X788 X8830 X8770 BROOKLANDS TESTS - 10-EX CAR PERFORMANCE. These tests were conducted to ascertain :- (a) The relative performance of 10-EX and a standard 40/50 touring car. (b) The effect of various alterations to the body in of 10-EX and the reduction in speed produced by balloon tyres. As it is proposed to use a 16-tooth axle on the sports Phantom in order to maintain good acceleration on top gear, this axle was fitted to the car when taken on the track. (a) The results of these tests shew that 10-EX is rather more than 10 m.p.h. faster than the standard touring car. Its acceleration through the gears is very much better than the standard car. Its acceleration on top gear up to 50 m.p.h. is now equal to standard, and above that speed considerably better. (b) The improvement in stream-lining of the body is so marked that the axle ratio proved too low to enable a satisfactory analysis of the various components to be made. As will be seen from the attached curves the road wheel H.P. is falling away very rapidly at 80 m.p.h. and at 90 m.p.h. or 2900 r.p.m. with a 16-tooth axle, valve bounce starts. Actually the valve gear on this car begins to be very noisy at about 2600 r.p.m. and at 2850 r.p.m. it is contd :- | ||