Table of contents: When a new cylinder block and…↓ When the cylinder block and…↓ The protrusion of the main bearing…↓
When a new cylinder block and crankshaft are used
1) The values in the top row of the main bearing selection table correspond to the bearing housing class (0, 1, 2 or 3), stamped on the rear 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 on the front of the crankshaft.
3) Select the main bearing class (STD 0-6) at the intersection of the horizontal row and vertical column in the main bearing selection table.
When the cylinder block and crankshaft are reused
1) Measure the inner diameter of the main bearing housing in the cylinder block.
2) Find the obtained result in the table of main bearing selection in the horizontal line "Inner diameter of the main bearing housing".
3) Measure the diameter of the crankshaft main journal.
4) Find the obtained result in the table for selecting main bearings in the vertical column "Crankshaft main journal diameter".
5) Select the main bearing class (STD 0 - 6) at the intersection of the horizontal row and vertical column in the main bearing selection table.
Main Bearing Selection Table
Unit: mm
Instructions for use of undersized main bearings
If the specified oil clearance cannot be achieved with standard size main bearings, use undersize bearings.
When using undersize bearings, measure the bearing inside diameter on the installed bearing and regrind the main journal so that the oil clearance is within specification.
Reduced oversize bearings
Caution: When regrinding main journals to accommodate undersized bearings, maintain the rounded corners on all main journals.
(Material borrowed from the website: nissanbook)
The protrusion of the main bearing above the plane of the bed joint
Install the main bearings and tighten the cap bolts to the required torque. Remove the caps. The edge of the bearing should protrude above the parting plane.
- Standard: There must be a protrusion.