THE results of research concerning the problem of fuel utilization in auotmotive engines are presented. A large heavy-duty six-cylinder engine was used, and the experimental apparatus and methods employed are described in the Appendix. Charts summarizing the engine characteristics at seven-eighths full-open throttle, the important characteristics determined by exhaust-gas analysis and the actual distribution of the fuel charge to the individual cylinders are presented. The characteristics indicated by these charts are discussed in some detail and the conclusion is reached that the higher engine-speeds used not only resulted in somewhat higher air-fuel ratios for the engine but also produced a more even distribution of the fuel charge to all of the individual cylinders.
The question is asked: Why did the center cylinders receive much richer mixtures than the end cylinders at the lowest speed, yet find themselves with practically the same mixtures as the end cylinders had at the highest speed? The author then makes certain assumptions and comments upon the data obtained in an effort to answer this question.
In conclusion, the author suggests that, since the primary function of the inlet manifold is to conduct the charge from the carbureter to the cylinders, the manifold should be designed so that it executes this purpose most effectively. Second, because he considers the engine as merely a mechanical converter of chemical energy, he believes that strict attention paid to the chemical phases should result in engines of much superior fuel-utilization characteristics.