SUPPORT AS 3968044 - Caterpillar

The nominal dimension is the desired dimension after the block has been machined. Each cylinder bore must be inspected at four vertical locations; two measurements, 90° apart, must be made at each location with a dial bore gauge. The gauge must be accurate to 0.0025 mm (.0001"). The machined bore must be within specification at each point measured.
It is important to chamfer the bottom of each cylinder bore after machining the bore to prevent scuffing of the piston skirt. See the article, "Check Cylinder Bores For Chamfer During Reconditioning," on page 5 of the February 14, 1983 Service Magazine.
Add this information in the appropriate Service Manuals. It will be added to the Service Manuals during their revisions.