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).
Vehicle performance tests under extreme temperature and high altitude conditions, detailing engine starting and boiling issues.
| Identifier | ExFiles\Box 149\4\ scan0392 | |
| Date | 20th August 1937 guessed | |
| ( 3 ) When analysed these results show that the critical temperature at which an owner would be aware of vapour trouble is 37°c with this system against 32°c with the parallel pump scheme originally fitted to the car. The figures given are the result of earnest endeavour to produce a failure which in the ordinary way would not occur below the critical temperatures mentioned. At these temperatures, the failure is bad enough to inconvenience an owner considerably, but a complete failure of the petrol supply as experienced with the low pressure dashboard and three pump scheme has not been produced even by the very extreme tests to which the system has been submitted. A Works' scheme, similar in principals to the Châteauroux scheme and regarded as more suitable for production is now being incorporated to obtain comparative figures of merit. During these tests, starting the engine usually required three to four attempts with air temperatures at 33°c and over. On the ascent of the Pic du Midi at 7,000 feet with air at 26°c, the engine started at the 3rd attempt, but two gallons of cold water had been added to the radiator and the bonnet left open for this purpose. At 8,500 feet after a 3/4 hour halt with the car standing on the level, the air temperature was 24°c U.B. 68°c Water 90°c Oil 72°c. The car had been boiling violently on arrival and losing water. The engine would not start. It was necessary to leave it standing for a further 3 minutes with the bonnet open. It then started after several further attempts and considerable quantities of black smoke were blown out. After this it idled perfectly with no signs of over-richness and was stopped and started again with no further difficulty. The only other trouble experienced under these very extreme conditions was boiling with consequent loss of water from the radiator. This is dealt with in a seperate report. ------------------ Rm{William Robotham - Chief Engineer}/IMW.{Ivan M. Waller - Head of Chateauroux} | ||