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Mechanical Engineering students at Texas Tech participated in the 1989 SAE Methanol Marathon in which a 1988 Chevrolet Corsica was converted to run on M85, a blend of 85% methanol and 15%hydrocarbon fuel. This report describes modifications to the Corsica accomplished in preparation for the continuation of this program, the 1990 SAE Methanol Challenge. The modified Corsica place second overall. In response to the 1990 program requirements, the Corsica was modified to enhance engine, transmission, and suspension performance. Engine modifications include improving cylinder head flow efficiency, changing cam profiles, modifying the engine bore and stroke, using lighter weight pistons with modified rings, using roller-tip rocker arms, enlarging the exhaust runner ports, and installing a specially developed catalytic converter system. The transmission was modified with a lower ratio fifth gear and the suspension was strengthened.

A single-cylinder, 4-stroke, spark-ignition engine was used to evaluate the effect of oxygen enriched air on engine performance and exhaust emissions. Evaluations were made with both gasoline and natural gas. The oxygen content of the intake air was varied between 20.9% (ambient air) and 25%. The effects of oxygen enrichment were evaluated in terms of power output, specific fuel consumption, fuel conversion efficiency, exhaust gas temperature, and exhaust emissions (carbon monoxide and hydrocarbons). Test results indicate that the use of oxygen enriched air produces a significant increase in power output, improved fuel conversion efficiency, lower specific fuel consumption, higher exhaust gas temperature and a substantial reduction in carbon monoxide and hydrocarbon emissions when the engine is fueled with either gasoline or natural gas.

A literature search to identify deleterious effects of using re-refined oil did not disclose any validated occurrences. Significant engine testing using re-refined lubricating oil is reported and no cases were discovered in which engine operation was affected negatively by the use of re-refined oil. The American Petroleum Institute (API) allows the use of re-refined base stock oils in the blending of end use lubricants. Based on oil sample testing performed in this research as well as other authoritative sources, it was determined that no significant chemical or physical differences exist between re-refined and virgin oils. Differences noted in this research were related to higher levels of poly-nuclear aromatics (PNA's) in the re-refined oil. PNA's are formed due to the extreme conditions of temperature and pressure during operation of an internal combustion engine.