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).
Carburettor, radiator and fan performance, detailing issues and modifications during hot weather testing.
| Identifier | ExFiles\Box 5a\3\ 03-page313 | |
| Date | 20th June 1933 guessed | |
| - 3 - due to expansion during the excessive hot weather. This was cured by lapping in the piston. The float chamber needle was inclined to make the carburetter flood owing to a ridge having worn on the taper. RADIATOR & FITTINGS Marston Mark.lll. type Matrix - 3.250 thick fitted using shutters & controls ex. radiator removed. The efficiency of the radiator was fully tested during two weeks of hot weather, the air temp. rising above 30°C. The highest water temperature reached was 94°C. During the period of hot weather the car was run without the fan, the result being no increase in water temperature, but an increase in oil temperature. We found that no difference was made with the bonnet shutters open or shut. It would rather point to the fact that the matrix size was not sufficiently large to allow the passing of any more air through it, and at speed the fan is doing very little actual work. The radiator has remained very steady, the anchorage has given no trouble. A thermostat made by the Packless Gland Co. was fitted and has run 7000 miles. It has operated quite as satisfactory as the standard one taken out. There has been no difference in the working temperatures. FAN LOP.XB.189. Complete to LOP. Peregrine type fan. Speed of fan reduced to same ratio as Peregrine. With this fan, the water came up to boiling point when the car was stationary and engine speed approximately 400 revs. per Min. On the road there was no trouble and it did not produce any noticeable roar. The standard 25 H.P. fan and drive was fitted. The trouble at low engine speed was overcome, but there was an objectionable roar at 50 miles per hour and over, comparing it with the Peregrine fan. We have during the mileage had two Dunlop fan belts break. They have not as previously suggested undergone any severe strain in being fitted too tight in the first place. The fracture appears to be due to the centre core being weak. | ||