When a new cylinder block and crankshaft is used
1) The values in the top row of the main bearing selection table correspond to the class of the bearing housing (0, 1, 2 or 3), stamped on the back of the cylinder block.
2) The values in the left column in the main bearing selection table correspond to the diameter class of the crankshaft main journals (0, 1, 2 or 3), stamped in front of the crankshaft.
3) Choose your main bearing class (STD 0-6) at the intersection of a horizontal line and a vertical column in the main bearing selection table.
When the cylinder block and crankshaft are reused
1) Measure the inside diameter of the main bearing housing in the cylinder block.
2) Find the result in the main bearing selection table in the horizontal line «Main bearing housing inner diameter».
3) Measure the diameter of the crankshaft main journal.
4) Find the result in the main bearing selection table in the vertical column «Crankshaft journal diameter».
5) Choose your main bearing class (STD 0 - 6) at the intersection of a horizontal line and a vertical column in the main bearing selection table.
Selection table for main bearings
Unit: mm
Guidelines for the use of undersized main bearings
If the specified oil clearance cannot be achieved with standard size main bearings, use undersized bearings.
When using undersized bearings, measure the inside diameter of the bearing on the installed bearing and regrind the main journal so that the oil clearance is correct.
Reduced oversize bearings
Attention: When regrinding the main journals for undersized bearings, keep the rounded corners on all main journals.
Protrusion of the main bearing above the bed parting plane
Install the main bearings and tighten the cap bolts to the correct torque. Remove covers. The edge of the bearing must protrude above the parting plane.
- Standard: Must have a ledge.