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).
Letter discussing difficulties with cold starting, comparing performance to American cars and detailing experimental solutions.
| Identifier | ExFiles\Box 50\3\ Scan028 | |
| Date | 3rd March 1921 | |
| OY1/G3.3.21. X4305 March 3rd. 1921. Mr. Claude Johnson Managing Director Rolls-Royce Ltd., London, England. Attention Messrs. Royce and Hives. Dear Sir, X3764 X.4305 RE EASE OF STARTING. As remarked by yourself in New York, the matter of ease of starting is a thing in which we suffer by comparison with the average American Car. Practically every owner of a Rolls-Royce car complains of difficulty in starting in wintertime, and we therefore wish to urge most strongly that a device for easy starting should be incorporated as soon as possible on cars sent to this country, and instructed for our production. On American cars, practically without exception, a "choker" is fitted, which is to say that the air inlet to the carburetter is almost closed so that the suction is violent enough to break up the petrol drawn from the carburetter jets and the vacuum sufficient to vaporize a portion of it even at low temperatures, so that a firing mixture is obtained in the cylinder. We are all very pleased to notice that this matter is receiving Mr. Royce's attention, and think it will be interesting to him to learn of such results as we have been able to obtain. In the first place, the heated induction pipes which we have tried, do not help the starting difficulty, because the pipe takes a minute or two to heat up, although any application of heat does help to get the engine running steadily sooner after starting. However, we have fitted experimentally on 4.EX a device coupled to the priming cock which, when the cock is opened, also opens an air cock over the extra air valve, and closes a slide over the low speed air intake. The slide allows a slight leakage of air, and a little air is also drawn in past the disc on the extra air valve and through the pin hole of the extra air valve. The priming cock being open, a quantity of petrol must be drawn through as well as through the low speed jet. In this condition, 4.EX may be started easily by hand or self-starter on the coldest morning, but will not run Contd. RC. {R. Childs} 20-1-19.10M.W&S (E5203) | ||