Masters Theses


Moris Bolay


"The object of this paper is to determine or rather experimentally establish the effect of a change in viscosity of a given diesel oil in regard to the ignition quality (cetane rating) of the oil.

The author did not attempt to prove why or find out how much the cetane number was affected. But, merely, tried to experimentally verify the fact that the cetane number of the fuel used underwent a change when its viscosity was decreased by preheating it.

Since his professional interests lie in the field of automotive engineering, several thesis problems were suggested to him by Dr. A. J. Miles, Chairman of the Mechanical Engineering Department, all to be investigated on the C.F.R. gasoline and diesel test engines. Originally “sensitivity” was taken as a thesis problem, for it was a fairly new subject not explored intensively. But later the facilities in the laboratory and the fact that diesel research is still a wide open field led the author to carry his experiments on the C.F.R. diesel testing engine. The author's original idea was to investigate a diesel fuel in regard to a simulation of “sensitivity” as established for the octane numbers of gasolines. He chose, as a first step in doing so, to investigate the relation the fuel viscosity would have on the cetane rating.

Up to 1930 not much research work had been carried out on diesel engines and especially on diesel fuel oils. The following decade, since the tendency toward increasing the speeds of diesel engines had caused them to become more sensitive to fuels and research on the latter had brought out the importance of ignition quality, research work was carried out to standardize a method of test by which diesel fuels could be rated. The importance of ignition quality and viscosity was first recognized by Mr. H. R. Ricardo and attempt in research in this respect was stressed by him"--Introduction, pages 1-2.


Miles, Aaron J.


Mechanical and Aerospace Engineering

Degree Name

M.S. in Mechanical Engineering


Five pages introducing sections of the thesis are not numbered.


Missouri School of Mines and Metallurgy

Publication Date



vi, 63 pages

Note about bibliography

Includes bibliographical references (pages 61-62).


© 1953 Moris Bolay, All rights reserved.

Document Type

Thesis - Open Access

File Type




Subject Headings

Cetane number
Diesel fuels -- Viscosity
Internal combustion engines -- Ignition

Thesis Number

T 1045

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