Examination of usability of vegetable oils as lubricants oil in gasoline engines

Today, the fast-increasing environmental problems, the concerns on the termination of fossil-based fuels, and the struggles for decreasing the dependency on foreign sources brought with them new searches in the field of energy. One of them is the search for using plant-based lubricating oils, which pollute the environment less, instead of the petroleum-based mineral oils in engines. In this study, 1 liter plant-based oil or 1 liter mineral-based lubrication oil were added to 25 liter gasoline in a 1 cylinder and 2-stroke engine to perform the experiments. The effects of using mineral engine oil and plant-based oils (canola and sunflower oil) on the running of the engine, the soot formation and the tribological performance of the engine were assessed in the study. In addition, the SEM photographs of the segments were taken and the effects of the different oils used in the study on micro structure were investigated. For this purpose, the segments of the 2-stroke engine were operated with mineral engine oil without coating. Then, the segments of the engine were coated with boron by using PVD (Physical Vapor Deposition) method and the engine was operated again. In the experiment in which th plant-based oils were used, the experiment was performed with the segments that were coated. The engine used in the experiments was operated under real working conditions with loads for 100 hours for each experiment. The engine was removed each time, and the soot formation, the pistons and segments were examined in terms of corrosion, and the results were compared. When plant-based oil was used as lubrication oil instead of mineral-based engine oil, it was determined that more corrosion occurred on the surfaces of the pistons and segments. In addition, it was also observed that there was more soot formation on the pistons and segments. As a conclusion, it may be claimed that the use of plant-based oils in two-stroke engine as lubricant does not yield good results.