Ls1 Engine Build Main Bearing Bore

Next, we measure the diameter of the main bearing bores. Since our block was not align-honed, we're not actually checking machine work here; just making sure these main bearing bores are within GM's specification for size and roundness. After torquing the main cap bolts to the proper spec in the GM service manual, our dial bore indicator tool is used to measure each bore in succession in both the vertical and horizontal planes. All measurements yield identical readings of 2.761 inches. While GM specifies production main bearing bore diameters of 2.750-2.751 inches, the discrepancy probably is due to limits of the measuring tool; the fact that all the measurements are the same is all that really matters. Plus, we'll be checking bearing clearances using Plastigage momentarily.

LS1 Engine Build - My First Stroker

Next, we measure the diameter of the main bearing bores. Since our block was not align-honed, we're not actually checking machine work here; just making sure these main bearing bores are within GM's specification for size and roundness. After torquing the main cap bolts to the proper spec in the GM service manual, our dial bore indicator tool is used to measure each bore in succession in both the vertical and horizontal planes. All measurements yield identical readings of 2.761 inches. While GM specifies production main bearing bore diameters of 2.750-2.751 inches, the discrepancy probably is due to limits of the measuring tool; the fact that all the measurements are the same is all that really matters. Plus, we'll be checking bearing clearances using Plastigage momentarily. View Related Article

Ls1 Engine Build Main Bearing Bore

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