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 on a 5-passenger closed sedan, detailing issues with cooling and piston failure.
| Identifier | ExFiles\Box 29\3\ Scan239 | |
| Date | 23th July 1930 guessed | |
| MARMON 8. 78. 5. Pass. Closed Sedan. COOLING. - This car had done about 375 miles when taken over. As will be observed from the attached details of the cooling system the radiator has a large frontal area and is very shallow. Every facility is made for getting air away from under the bonnet, the louvres being of generous dimensions and the undershield a mere skeleton. It is difficult to understand how the engine is kept clean. The cooling tests were not of much value as the only continuous running we did was at 52 M.P.H. From these it does not compare favourably with a Phantom II having a ventilated bonnet. After 410 miles we attempted to get a speed figure over the mile and while travelling at about 64 M.P.H. the top came off No.1 piston and fortunately wedged at the top of the bore without causing further damage. We had previously allowed the car to stand for half an hour to cool and had only covered 3/4 of a mile after this pause when the incident occurred so that there was little justification for the failure. SPEEDOMETER. - The speedometer figures are typical of many American cars we have tried. We estimate the maximum lap speed of the car would be about 57 M.P.H. ACCELERATION. - The acceleration of the car was very good up to 50 M.P.H., being quite equal to that of Phantom II. This we should expect with its low axle ratio and fair sized engine giving a displacement/ton mile of 4480 Litres. Clearly from this we cannot expect the 20 H.P. to compete with it for | ||