Related Photo Galleries
Once the main bearings have been installed, the main caps must be torqued down before checking bearing clearance. Using a dial bore gauge to measure the bearing inside diameter, then comparing it to the diameter of the main journals measured with a micrometer will give a good indication of the bearing clearance. As long as a block is in good shape, or has been align-honed, variations from cap to cap should be minimal, and can be adjusted if necessary with undersized bearings. For street engines, 0.0025- to 0.0035-inch clearance is typical, while race motors may have 0.0035 to 0.0040 inch of clearance.