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).
Vehicle performance, discussing steering vibration, engine characteristics, and other features.
| Identifier | ExFiles\Box 65a\2\ scan0145 | |
| Date | 15th December 1928 guessed | |
| contd :- -2- and and equivalent vibration or movement set up in the steering column. This jellying would vary in extent with the roughness of the road and the speed along which it was traversed, and this is a point which we are considerably concerned with because, if we were so much struck with it yesterday under the difficult conditions of our run, we feel the amount of this undesirable movement would probably become extremely noticeable and perhaps excessive, when running at high speeds on bad roads in France. The Expl: Dept: is perfectly aware of this characteristic; they state that they are entirely optimistic as to the chance reason-ably easily of dealing with this point. Therefore we mention it as one which must concern us with considerable interest. With regard to the engine characteristics, it was undoubtedly very pleasant to have the advantage of an additional 400 revs. doing useful work, and we understand that it is antici-pated the ultimate useful speed of this type of engine will be higher still. This, of course, enables higher road speeds to be obtained without interfering with existing gear ratios. We found that the picking up vibrations, sometimes referred to as torque reaction vibrations, of this engine when accelerating to say 30 m.p.h. were not excessive, they are probably equivalent to the vibrations which we had to put up with in the 'AL' series and it must be noted that the present engine is supported in the frame on four feet and is not 3-point suspension. In addition, at present these four feet are sandwiched between rubber blocks. This part of the engine design is still in the condition of flux, the next experiment being to remove altogether the rubber pads from the front supports, it being hoped in this way that with the conditions to be met with in general running, better results will be attained from the point of smooth picking up, but experiment will, of course, finally decide this. We are satisfied that the engine as it stands is acceptable from this point of view. There are two other features which we consider will require very careful watching : (a) The succesful operation of the clutch stop which, as arranged at present, is not satisfactory. (b) The succesful operation of the starter motor and control, which at present functions intermittently only. We have no reason to think that any undue anxiety need be felt in respect of these two items. The modified steering wheel on this car gives the impression of looking considerably bigger in diameter, but as a matter of fact is only half an inch larger, the rim itself being reduced in section. We like this wheel quite well. We consider that the steering control on this car is not as Contd:- | ||