Elements of Aviation Engines (Paperback)

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1918 edition. Excerpt: ... CHAPTER V CARBURETION In Order that gasoline may be mixed with the right amount of air to form an explosive mixture within the cylinders, it is necessary to make use of a device known as a carburetor. A great deal of attention has been devoted to the designing of carburetors, for it can be readily seen that the fuel consumption of an engine will be governed largely by the performance of the carburetor. Also of late much attention has been given to the carburetion of lower grade fuels, so the subject of carburetors is becoming a broad field. A suitable mixture for an aviation engine is one pound of gasoline to fifteen pounds of air. A richer mixture would be one having more gasoline, while one having more air would be a leaner mixture. It has been found that the most practical way to obtain this mixture is to spray the gasoline into the air, and this is best accomplished by making use of a jet attached to a reservoir and lessening the atmospheric pressure about the jet. If the level of gasoline in the reservoir is slightly lower than the tip of the jet and the jet is located in an air-supplied chamber having a connection with the inlet valves, the downward motion of the pistons will result in less pressure being exerted upon the gasoline in the jet than that in the reservoir, where atmospheric pressure is exerted. Gasoline in this way will be made to flow from the jet, and since considerable air is being drawn past the jet it will tend to form a spray of the gasoline that is being delivered. To restrict the amount of gasoline that is supplied to the float chamber which in turn has a great deal to do with the gasoline delivered by the jet, the float with which the float chamber is supplied, actuates a pin that opens and closes the main...