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).
Test report on the S.S. Car 20-EX, detailing points for consideration regarding engine vibration, steering, and performance.
| Identifier | ExFiles\Box 65a\2\ scan0235 | |
| Date | 1st February 1929 | |
| PRIVATE X7770 To Hs.{Lord Ernest Hives - Chair} C. Worsley from EP.{G. Eric Platford - Chief Quality Engineer} & Mx.{John H Maddocks - Chief Proving Officer} EP{G. Eric Platford - Chief Quality Engineer}6/H9.2.29. re. S.S. CAR. 20-EX. In testing the above car with Mx{John H Maddocks - Chief Proving Officer}, we are still impressed with the fact that in spite of the criticisms one could make, the car is a nicer one to ride in and to drive than the present standard Phantom. The following ,however, are points for consideration:- (1) Engine vibration and front "jellying". The "jellying" of the front of the car does not appear to exist at all on this chassis, and although the engine vibrations generally are less objectionable than on 19-EX, they are certainly not as good as 18-EX. In view of the above we suggest that the best compromise has not yet been obtained with the engine mounting, and that a little further flexibility in the mounting of the engine can be achieved without producing the "jellying" effect which was so pronounced on 18-EX. The definite improvement in torque reaction vibration as compared with the present standard Phantom is still maintained, and is a marked advantage. On the contrary the engine suffers from high speed "sting" and retard vibrations, also periods of engine local roughness at 45 - 50 m.p.h. The engine also appears to suffer from slight engine gear thrashing or "throbbing". I suggest that the latter point may be due to the slipper drive not working satisfactorily for this engine (18-EX O.K. in this respect). (2) Steering. One does not feel to have sufficient definite control of the car on uneven roads, also even for slow speed steering there seems to be rather more damping than is required. The steering in its present state will be a source of complaint from customers. The controls rattle (high engine speed vibrations). The position of the steering wheel on this car does not seem very comfortable, and one realises the discomfort of the steering controls being too high. The thin steering wheel is a favourable feature. (3) Performance and Carburation. The performance of the car seems quite good. The carburation,however, as regards acceleration is bad, CONTD:- | ||