How to Apply Induction System to Actual Automotive Multi-Cylinder Engine under Considering Improvement of Volumetric Efficiency

Abstract

It is known that volumetric efficiency at a given speed under full open throttle varies with the induction system attached to the carburetor. Then constant diameter of different length was used as simple added induction system. The relationship between the engine speed showing maximum volumetric efficiency and the length of these pipes was analysed in order to find out the equivalent acoustic characteristics applicable to the induction system from the carburetor to the piston. The equivalent acoustic system of engine having the same characteristic as above could be found, which consists of one chamber with certain amount of volume, one pipe and one venturi located between the two. In order to obtain improved volumetric efficiency under normal engine speed range, some experimental added induction systems were designed by simulating the equivalent acoustic system of the engine on an electric circuit, and the test results conformed to the practicability of the above analysis.