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Four different vegetable oils, degummed soybean, once refined cottonseed, peanut and sunflower oils, were injected into a high-pressure, high-temperature environment of nitrogen. The environment was controlled to resemble, thermodynamically, conditions present in a diesel engine at the time of fuel injection. Samples were removed from the sprays of these oils while they were being injected. A sonic, water-cooled probe and a cold trap were used to collect the samples. Chemical analyses of the samples indicated that significant chemical changes occur in the oils during the injection process. The major change is the formation of low-molecular weight compounds from the C18:2 and C18:3 fatty acids.

It is now a fairly well established fact that excessive ring and cylinder bore wear can result from the operation of an S. I. engine on neat methanol. The mechanism leading to the excessive wear were investigated using both engine and bench tests. Engine tests using prevaporized superheated methanol indicated that the wear results from reactions between the combustion products and the cast iron cylinder liner, where the presence of liquid methanol in the combustion chamber appears to be an important part of the mechanism. These reactions were investigated using a spinning disc combustor. The spinning disc combustor was used to provide a source of burning methanol droplets which were subsequently quenched on a water-cooled cast iron surface. The condensate formed on the cast iron surface was collected and analyzed for chemical composition. Infrared analysis indicated the presence of large quantities of iron formate, a reaction product of iron and formic acid.

As a part of an overall project to improve the techniques for rating the ignition quality of diesel engine fuels, the experiments described in this paper involve examination of the relationship between cetane number and both the physical and chemical ignition delay times. The ignition delay times have been determined from accurate pressure histories obtained during the injection and ignition of a variety of test fuels in a constant volume combustion bomb using a quiescent, high-temperature, high-pressure air environment. The test fuels have included blends of the primary reference fuels as well as other fuels selected because of specific physical properties or chemical composition. The correlation between the cetane numbers of the fuels and various ignition delay times are examined.