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.