Coastal fishing vessels use high speed diesel engines on board. A lot of problems regarding cold start are reported, for example, white smoke emission in winter when low ignition quality fuel is used. We conducted cold start tests for a small size direct injection diesel engine under the conditions of the fuels with a variety of cetane index and evaporability. White smoke emission become worse when the fuel with low cetane index was used, or the fuel with higher 50% distillate temperature was used. The effect of increasing the 50% distillate temperature with 30 °C was equivalent to decreasing cetane index with five. We also observed high CO emissions of cold start when low cetane index fuels were used.

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In the present study, the sliding wear process of white metal lined bearing was studied under a several static loadings with various rotational speeds of the shaft. And effects of both the shaft revolution speed and compressive contact stresses on the damage evolution and cut-off fatigue lives of the bearing were investigated. The experimental results were considered and discussed on the basis of the frictional stress between the shaft and the bearing. As a result, it was clarified that the cut-off fatigue lives of the bearing under various testing conditions involving contact stresses as well as shaft speeds were determined only by the amount of the frictional stress between shaft and the bearing. Also there is the endurance limit τ_w (= 0.2MPa) for the present bearing, below which no damages initiate on the sliding surface of the bearing.

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