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 issues concerning frame jellying, lubrication in cold weather, and ground clearance in snow.
| Identifier | ExFiles\Box 178\2\ img145 | |
| Date | 4th April 1934 | |
| -2- At high speeds the car was comfortable and held the road well, even when the front shock absorber load had been considerably reduced. (2) FRAME JELLYING. This was noticeable from the wing movement, and undoubtedly emphasized by the stiff front springs. Most of the American cars have dealt with the trouble either by stiffening their frame or by centrally mounting the front wings as well as the radiator. The Packard is a particularly good example of a solution of the trouble by the first method. (3) LUBRICATION. The oils used must be completely revised for zero conditions. The ordinary Bijur oil will not flow at all at 0°F.{Mr Friese} The steering, when filled with engine oil, becomes noticeably heavy and the gear shift uncomfortably so at this temperature. There is not the remotest chance of starting the car at temperatures of 25°F.{Mr Friese} or lower with any of the English oils such as Castrol X.L. or Mobile E.{Mr Elliott - Chief Engineer} The Americans have what they call a S.A.E. 20.W. and an S.A.E. 10.W. oil. It will be realised how thin these are when it is pointed out that Mobile Artic as sold in England is slightly heavier than the thicker of these two oils. It is common practice in severe winters such as that just terminated, to use S.A.E. 10.W. oil and add 30% of kerosine. The Bentley was run on Mobile Artic, the most noticeable disadvantage of using this oil is the increase in engine noise, particularly in the timing gears, for this reason no thinner oil was tried. (4) GROUND CLEARANCE. Running under snow conditions it is essential to have the same clearance as the average American car or one grounds on the frozen snow piled between the tracks. This could be accomplished by larger wheels and springs having slightly more initial camber. | ||