Balancing Power-Output in Multi-Cylinder Engines 290014

AN INVESTIGATION of the problems of fuel-mixture distribution in the cylinders of internal-combustion engines recently initiated at Purdue University is outlined by the author, who states his belief that the material submitted in his paper demonstrates that it is necessary to “get inside” an engine cylinder to obtain satisfactory data. He therefore presents and comments upon indicator diagrams from tests made on the road and in the laboratory.

The effects of pulsations in the manifold of an engine having a rather complicated manifold system are studied by means of lower-loop light-spring diagrams, and diagrams obtained from six cylinders of an engine operating at about 0.7 load at 1400 r.p.m. are analyzed.

The effects of changing the mixture delivered to one cylinder of an automobile engine are also illustrated and analyzed.

Phases emphasized in the discussion include statements of one of the means of measuring mixture-distribution whereby the gas is passed through a cell equipped with a heated platinum filament, the catalyzing action of the platinum completes the combustion and the effect is recorded on an indicating instrument; experimental work in measuring the detonating characteristics of fuels; changes in manifold design which resulted from one company's experimental work; reasons why procedure on the premise that a true mixture is received at the manifold is unwarranted; a suggestion of the possibility that quartz windows can be installed in the combustion-chamber of each cylinder and spectrographs used to study actual conditions; and comments on straightening out the airstream and diffusing the fuel in this airstream, with mention of a device for recording distributon results during road tests.