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).
The cooling system performance and boiling issues of the Phantom III experimental car 32-EX.
Identifier | ExFiles\Box 131\1\ scan0293 | |
Date | 17th August 1937 | |
CHATEAUROUX. Rm{William Robotham - Chief Engineer}/IMW{Ivan M. Waller - Head of Chateauroux}/3/JAB.17.8.37. To. Rm.{William Robotham - Chief Engineer} c. Rm{William Robotham - Chief Engineer}/Std. c. Rm{William Robotham - Chief Engineer}/GWH.{George W. Hancock - Head Chateauroux} 1114 hobin Rm{William Robotham - Chief Engineer}/SD? 32-EX, PHANTOM III. Cooling System. Replying to your memo Rm{William Robotham - Chief Engineer}/Std.4/AP.10.8.37, re boiling, our answers are as follows:- a) We have not yet been able to carry out comparative tests with a clean radiator to verify the extent to which the insects have reduced the cooling. b) Yes, the steam valve has opened when the radiator has boiled and considerable quantities of water lost. On the Pic du Midi, the initial section consists of a rise of 4,700 feet in 11 miles from Luz to the Col du Tourmelet. The air temperature was 32° to 26°c. Boiling started almost at once and it was necessary to add 2 gallons of water at the Col, to fill to the normal running level. On the remaining 1,500 feet in 3.1/2 miles to the top, a further gallon was lost and the steam valve was making a noise like a ship's siren. The air temperature in the final section was 26°c. The climb was made in a normal manner, second gear being required most of the way up. The high speed fan drive was in use. On the Col de L'Iseran with Rm.{William Robotham - Chief Engineer} and Mx.{John H Maddocks - Chief Proving Officer} the air temperature was 24° at the start of the climb, 21° near the top, and 13° on the summit. No boiling was apparent but the thermometer frequently registered 100°c and at the end of the day's running which also included another difficult pass, three pints of water were required to bring the level up to normal. This can be regarded as satisfactory from an owner's point of view, but the performance on the Pic du Midi with high air temperatures was not satisfactory c) The higher speed fan drive was fitted on August 1st. and has been in use since which includes these tests. We have boiled and lost water by sustained speed on the level with air temperature at 33°c using overdrive gear. The ultimate water temperature reached with sustained speed in overdrive when checked after 13,500 miles was 93°c with air at 24°c The boiling experienced produced subsequent leaks from the rubber hose connections which were overcome by tight-ening up the jubilee clips. RM{William Robotham - Chief Engineer}/IMW.{Ivan M. Waller - Head of Chateauroux} | ||