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).
Comparing an exhaust heated throttle with a vaporiser scheme for cold weather performance and making recommendations for American cars.
| Identifier | ExFiles\Box 31\3\ Scan068 | |
| Date | 1st November 1921 guessed | |
| -3- experience with the device to believe that we can achieve an improvement in running in every case. The expense of the exhaust heated throttle is we believe greater than the vaporiser scheme because it involves actuating a mechanism, large diameter pipe work and a new throttle casting, scrapping our existing castings, 160 of which have been final-machined. (f) From Mr. Hives' experimental results in England, we understand that the exhaust heated throttle causes an appreciable drop in horsepower. (g) We do not claim that the vaporiser scheme without the heated throttle is the ultimate perfect device, but we believe that in its latest development, as tried out under cold weather conditions on our experimental car, it is a sufficiently definite improvement to give satisfaction to users of our cars under winter conditions, and is a distinct advance on the standard English pipe and on the heater pipe which we fitted on cars last winter and which gave satisfaction to many Rolls-Royce owners. Our recommendation would be that for this winter we adopt on American cars for production and for necessary service work - (1) Vaporiser induction pipe scheme. (2) Pilot jet with moving choke, and (3) Recommend the use of Winterfront radiator shutters. An owner who has these three fittings on his car will be able to run it successfully under cold weather conditions with any commercial gasoline of standard quality at present supplied. Experimental development work for future improvements is still necessary and should be undertaken vigorously this winter both at Derby and Springfield. In doing this we shall only be doing what every automobile manufacturer in the country is forced to do by the constantly deteriorating quality of the gasoline and the growing demands of the users for perfect operation. It is felt by us and by most American manufacturers at the present time that the ultimate development along those lines will render it possible to use straight kerosene as fuel as a necessary measure towards conservation of fuel. We propose replying to Mr. Royce's cable along the following lines:- | ||