Big end bore size


The big end bore is machine-manufactured with the connecting rod and bearing cap. Due to unevenness in machine manufacturing precision, differences in big end bore size can occur. For that reason, there are several standard big end bore sizes. The size code of each bore is inscribed on a bearing cap. Use this code when selecting bearings to improve the connecting rod oil clearance precision in order to prevent abnormal noise and seizing and to maintain good fuel economy. As the size code increases, the big end bore size increases in micron units. Number of standard sizes and size coding differ according to the engine models.

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