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 development and testing of a hot spot induction system for use with low-grade gasoline.
| Identifier | ExFiles\Box 50\3\ Scan127 | |
| Date | 12th July 1921 | |
| X .4305 Extract from RB{R. Bowen}/G12.7.21. U.S.A. COMPLAINTS. X.3719. Hot Spot Induction System etc. Regarding the heated induction system for the low grade gasoline, there is not the slightest doubt that it would be waste of time to fit anything but an equipment which is proved to be a distinct advance on what we are at present fitting. Your arrangement on our tests shews no distinct improvement, and as we cannot adopt everything we must have some thing better. It is probable with your limited means of testing that you were at a disadvantage owing to some slight temperature difference in the water heated throttle, or profile of the pipes. Personally, I think you are doing quite wrong in abandoning the thermostat control of the circulating water, because this ensures the highest temperature possible around the carburetter and throttle (which our tests shew definitely beneficial) that can be obtained with water. Any slight increase of temperature around the throttle is of the utmost importance to the distribution of the gasoline. Exhats heated throttle and exhaust choke. We have at present on the road two or three modifications of heating the throttle by the exhaust gases, and one of the combinations of butterfly valve in the rear exhaust pipe and-one-of as shewn on the complete drawing sent herewith, which is undoubtedly the best thing we have done, the temperature of the throttle being distinctly higher than with water, and the effect on the distribution most marked. R.{Sir Henry Royce} | ||