Crankshaft journal surfaces should be ground and polished to a surface finish of 15 micro inches roughness average Ra or better. Journals on highly loaded crankshafts such as diesel engines or high performance racing engines require a finish of 10 micro inches Ra or better.
To prevent rapid, premature wear of the crankshaft bearings and to aid in the formation of an oil film, journal surfaces must be ground opposite to engine rotation and polished in the direction of rotation.
https://www.mahle-aftermarket.com/na/en/support/installation-tips/crank-grinding-and-polishing.jsp
CRANKSHAFT GRINDING SPECIFICATIONS
Bearing Size Crankshaft Main Journal OD Crankshaft Rod Journal OD
Standard 79.324--79.350 mm (3.1229--3.1240 in.) 77.800--77.826 mm (3.0629--3.0640 in.)
0.25 mm (0.010 in.) Undersize 79.074--79.100 mm (3.1131--3.1141 in.) 77.550--77.576 mm (3.0531--3.0541 in.)
Main and Connecting Rod Journal Surface Finish (AA) .....................Lap 0.20 um (8 AA)
Thrust Surface Finish (AA) ..................................................................Lap 0.40 um (16 AA)
Thrust Bearing Journal Width ..............................................................38.952--39.028 mm (1.5335--1.5365 in.)
Direction of Crankshaft Rotation (viewed from flywheel end):
Grinding ...............................................................................................clockwise
Lapping ................................................................................................counterclockwise
Engine Stroke ......................................................................................127 mm (5.00 i
http://constructionexcavators.tpub.com/TM-5-3805-280-24-2/TM-5-3805-280-24-200248.html
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