Simple Measuring Method of Air and Fuel Quantities Distributed to Each Cylinder of Multi-Cylinder Engine 785099

To evaluate and optimize multi-cylinder engine performance (output, fuel economy, exhaust gas emission, vibration, etc.), it is necessary to clarify the quantities of air and fuel distributed to each cylinder according to the engine speed and the carburetor throttle opening, and to clarify the correlation between the above characteristics and the engine performance.

From this point of view, some "survey" fuel with a known quantity was supplied to the position just in front of the intake valve of each cylinder of a provided test engine to obtain the distributed quantities in each cylinder from the changes of air-fuel ratio at that time, and the accuracy of this method was studied accordingly.

As the result, it was clarified that (1) the mixture distribution (that of the carburetor or the fuel injection engine) under steady state operation can be measured accurately by employing an ordinary automotive gas analyzer (CO, CO₂ and HC), and that (2) some possibilities exist as to measure the mixture distribution under transient state operation.