| Energy and environmental concerns have created a major thrust in the United States towards utilizing alternative fuels for internal combustion engines. One of the problems in utilizing alternative fuels such as alcohols is the effect it has on the engine and its lubrication system. Lubrication studies for alcohol fueled engines are usually conducted using fleet or actual full scale engine tests. The main contribution of this research is the development of a simple, rapid and inexpensive bench scale test protocol to help evaluate the influence of alcohol fuels on the lubricity and oxidative stability of lubricants under conditions simulating engine performance. The test protocol was developed using methanol as the primary alternative fuel, however modifications as required, were made in order to evaluate lubricants for use with M85 (methanol + 15% gasoline) and ethanol as potential alternative fuels. This test protocol helps understand the problems in lubrication of alcohol fueled engines from a fundamental point of view.; In the case of alcohol fuels, small amounts of alcohol in the crankcase causes phase separation of components of the lubricant basestock and additive package, leading to excessive wear and/or lubricant degradation. In contrast, in the fuel injection system, small quantities of the lubricant are exposed to large quantities of the alcohol fuel which can lead to extract (fuel soluble) and raffinate (fuel insoluble) phases which can cause injector plugging and/or excessive injector wear. Various lubricants and lubricant fractions generated have been tested using the designed bench scale procedure and their results help understand, and demonstrate potential problems for lubricants used for alcohol fueled engines. Preliminary work on modeling the oxidation kinetics of deposit forming tendency of lubricants has also been incorporated into this study.; This bench scale test can serve as an excellent precursory evaluation technique to screen lubricants for use with alternative fuels before expensive engine tests are performed and is a very useful tool to both researchers and industry. |
