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).
Technical memo discussing carburettor modifications, alternative fuels, and methods to prevent engine boiling.
| Identifier | ExFiles\Box 75\2\ scan0257 | |
| Date | 8th September 1921 guessed | |
| Oy3 - C 8921 Sheet #3. because it increases the compression pressure for a given brake horsepower, because the air is lighter and the cylinder has to fill up more for a given power output. He says that an exactly comparable scheme is used by the oil companies for cracking fuel oil for gasoline. It is found far more effective to blow air heated to 1000°F.{Mr Friese} or so in this case across a fine spray of crude oil than to crack the oil in a retort. On his Paige, which is a model which has always suffered from boiling when driven hard, he has taken off the fan, when fitting his carburetter, and the car does not boil under any conditions of running even in this warm weather, when several of our own cars, driven by our best drivers and without blanking plates, have given trouble from boiling whenever they are driven hard. He is going to fit an improved type of his own carburetter (on the left hand side of course) to his Rolls-Royce, and is going to show us what he can do! He thinks he can show us decreased consumption, increased power, and no boiling even when the radiator is blanked off to half its area in hot weather. We shall see. The parts are well on in production in a local shop. Meanwhile his explanation is that liquid fuel slopped in gives "after-burning", which heats the water and overheats the engine while producing practically no power. But if blown in in a fine spray, the same fuel will do useful work with a minimum of waste heat. Whatever the explanation, the Paige is a living proof that much can be done to avoid overheating. He also is a great believer in drains, but favors "re-blowing" the liquid fuel with a low air pressure and spraying nozzle rather than boiling it. He says he has been able to run his Paige perfectly economically on commercial kerosene without dilution or carbon deposit and without any other source of heat than the air supply, and by using an air jet blowing across the fuel jet he can start from cold on kerosene. (Incidentally do you recall that, at J.{Mr Johnson W.M.} C. Royce's suggestion, we strongly recommended an adequate hot air stove with seasonal adjustment, way back in December 1918?) Prof. Anderson ran his Rolls-Royce accidentally for 80 miles with standard carburetter and heated through pipe, quite successfully (though with what dilution or carbon formation we do not know) on a mixture of 1 gallon of "light" (.68 - .70) gasoline and 6 gallons commercial kerosene the other day, through an error in a filling station. | ||