Engine Block Disassembly, Inspection & Repair: Inspection

1. Visually check the cylinder block for scores, rust and corrosion, rust and corrosion.

   Also check for cracks or any other defects using a proper tool. Repair or replace the block if defective.

2. Measure the cylinder bore with a cylinder gauge at the three levels indicated in the directions of A and B.

   Level 1: No. 1 piston ring position with piston at TDC.

   Level 2: Center of cylinder.

   Level 3: Bottom of cylinder.

   Fig 1: Measuring Cylinder Bore With A Cylinder Gauge

   Courtesy of KIA MOTORS AMERICA, INC.
3. If the cylinder bores show more than the specified out-of round or taper, or if the cylinder walls are badly scuffed or scored, the cylinder block should be rebored and honed. New oversize pistons and rings should be installed.

   Standard value:

   Cylinder bore: 93.00-93.03 mm.

   (3.66-3.663 in)

   Deviation of concentricity and taper of cylinder bore:

   0.02 mm (0.00079 in) or less.

4. If a ridge exists at the top of the cylinder, cut it way with a ridge reamer.
5. Oversize pistons are available in two sizes.

   Oversize piston size:

   0.25 O.S.: 0.25 mm (0.01 in)

   0.50 O.S.: 0.50 mm (0.02 in)

6. To rebore the cylinder to oversize, keep the specified clearance between the oversize piston and the bore, and make sure that all pistons used are of the same oversize. When measuring the piston outside diameter measure the section of the thrust surface at 10 mm (0.39 in) above the bottom of the piston skirt.

   Clearance between piston and cylinder wall:

   0.03-0.05 mm (0.001-0.002 in)

7. Check the flatness of the upper surface. If the top surface exceeds limits, grind it to a minimum limit value or replace. (Measuring method is same as that of cylinder head flatness.)

Fig 2: Checking Flatness Of Upper Surface

Courtesy of KIA MOTORS AMERICA, INC.

Standard value

Flatness of the gasket mating surface:

Less than 0.05 mm (0.002 in)

Limit Flatness of the gasket mating surface:

0.1 mm (0.0039 in)