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).
Report discussing the radiator grille, ground clearance, and tyre sizes, comparing them to Cadillac and Bentley models.
| Identifier | ExFiles\Box 4\1\ 01-page129 | |
| Date | 9th October 1934 | |
| -5- Hs{Lord Ernest Hives - Chair}/Rs{Sir Henry Royce's Secretary};11/KW.9.10.34. Radiator Grille. There are two points in connection with the radiator grille, (1) in its present form it presents a definite obstruction to air flow, reducing the radiator efficiency by about 12%. (2) with the water heated hot-spots we find that the carburation is sensitive to the air temperature under the bonnet. Experiments on the Bentley have shown that with radiator shutters the temperature under the bonnet is higher than with the grille, particularly in cold weather. If we run the Bentley with a grille we find that the pick-up is affected. We are experimenting with a scheme of thermostatically controlled air intake from the exhaust pipe to get over this trouble. Ground Clearance. As previously pointed out, we are 3" lower on the silencer than the Cadillac, and 2½" lower on the crankcase. It is proposed to fit the SpectreCodename for Phantom III size wheel and tyre which will raise the car 1/2". There is therefore still about 1½" increase in ground clearance which we may expect to have to obtain by altering the normal running positions of the suspension. We should like to see a layout showing exactly what this means on the car, as it means altering the angle of the front arms. Tyre Sizes. We are in favour of using a smaller section tyre size on the SpectreCodename for Phantom III than is fitted to the Cadillac. Our experience of these very large section tyres at present in fashion on American cars is that they are not on the whole suitable for English conditions. When run at the inflation pressure which admits the increased comfort for which they are designed they do not appear to be stable on corners. We wore out a set of Cadillac rear tyres in 3,000 miles. Clearly our experience in the matter is very limited, but we are not opposed to the adoption of the SpectreCodename for Phantom III size of tyre for the time being at any rate. | ||