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 detailing vehicle cooling system performance, fuel consumption, and temperature readings during extensive road tests.
Identifier | ExFiles\Box 78\1\ scan0135 | |
Date | 11th August 1931 | |
tight. All the following temperature readings were taken on my ether thermometer, which I have not checked though I think it is pretty accurate. With the bellows carrying plate, i.e. this thing, screwed right home, the thermostat operates on a hunt of 90°-87°C. In order to ensure a real tight closing of the valve I have usually had this plate unscrewed about 1 1/2 turns which slightly raises the temperature. And all the following records were taken with it in that state. I have run 5000 miles with it, Land's End to John o' Groats on top gear & following hills:- Porlock, Lynmouth, Lyn, Cairn o' Mount, Glen Coe, Rest & be Thankful, Amulree, to Glen Lyon, Killhope, Hartside, Honister (from Buttermere side), Newlands, Kirkstone, Hawley Head, Wharfdale, Greenhow etc etc in fact all the hills I could find. She only boiled twice & on both occasions the fan belt had broken. The temperature hunted always from 91 1/2° to 88 1/2°C, about 3 hunts per minute. The petrol consumption on the 3000 mile trip which included all the above was 14.2 mpg. with both lock pinion & car weight of 50 cwt. After my talk with you & Mr. Hives recently I carried out the following test. I climbed Hindhead from the East, a rise of nearly 500 ft in 2.9 miles, with the mixture full strong, the ignition fully retarded, and the governor right up with the brakes on so as to reduce the speed to just below 30 m.p.h. The thermometer hunted from 95° to 92°C, three hunts per minute. There was a light 5-7 mph. following East breeze. I then repeated the test exactly but braked to below 20 m.p.h. The thermometer hunted from 93° to 91°C not quite three hunts per minute. 95° & 93° respectively were the maximum temperatures reached. I have the high speed fan, no blanking plates & no compression plates. These results are interesting in that they show that the increased cooling obtained at 30 mph. is insufficient to counteract the greater dissipation of heat necessary with the | ||