ABC's of Carburetion



	THE CARBURETOR'S JOB Continued

	FLEXIBILITY Changes in engine and air temperatures, altitude and manifold vacuum all affect the weight and volume of the fuel and air. These factors and others may affect the mixture and distribution to such an extent that combustion is erratic or does not occur at all. The carburetor must be able to anticipate and allow for such changes so that a combustible mixture reaches the cylinder.

		< MANEUVERABILITY The carburetor must satisfy the demands of a critical automobile operator, who desires smooth acceleration, quick response to rapid throttle maneuvers, quick starts and stops, proper operation on steep inclines, in all kinds of weather.

	ACCELERATION For acceleration, additional fuel is needed momentarily for the transfer to a higher speed. The principal reason for the need for more fuel is the difference in weight of the fuel and air. When the throttle is opened, acceleration of the air stream is nearly instantaneous. The fuel, however, is many times heavier than air and cannot accelerate as rapidly, so until the fuel flow "catches up" with the air flow, the mixture is excessively lean. The accelerator
		pump supplies extra fuel to offset this momentary leanness; without the extra squirt of fuel at the right time, the engine sputters or hesitates.

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