Cylinder Block

Using feeler gauge and straightedge, check cylinder block head surface warpage. If warpage exceeds specification, replace cylinder block. Ensure cylinder block height is not less than minimum specification. See CYLINDER BLOCK table under ENGINE SPECIFICATIONS.
Check diameter of cylinder bore. Different cylinder bore sizes are used and can be identified by size marks on deck surface of cylinder block. See Fig 1 . Ensure diameter of cylinder bore is within specification. See CYLINDER BLOCK table under ENGINE SPECIFICATIONS.
If diameter of cylinder bore exceeds 3.1571" (80.190 mm), bore cylinder block for oversize pistons. Oversize pistons are available in 2 sizes. See OVERSIZE PISTON SPECIFICATIONS table.

OVERSIZE PISTON SPECIFICATIONS

Oversize Piston In. (mm)

Oversize Piston Diameter In. (mm)

Cylinder Bore Diameter In. (mm)

.020 (.05)

3.1671-3.1679 (80.444-80.464)

⁽¹⁾ 3.1693-3.1701 (80.500-80.521)

.040 (1.00)

3.1868-3.1876 (80.944-80.962)

⁽²⁾ 3.1890-3.1898 (81.000-81.021)

⁽¹⁾	Maximum cylinder bore diameter is 3.1768" (80.690 mm).

⁽²⁾	Maximum cylinder bore diameter is 3.1966" (81.194 mm).

Fig 1: Identifying Cylinder Bore Diameter

Courtesy of ISUZU MOTOR CO.