Cylinder Block

Check the cylinder block for scores, rust and corrosion. Also check for cracks or any other defects. Replace the block if defective.
Measure the cylinder bore with a cylinder gauge at the three levels indicated, in the directions A and B.
1. Level 1: No. 1 piston ring position at TDC
2. Level 2: Center of cylinder
3. Level 3: Bottom of cylinder
  
  Fig 1: Measuring Cylinder Bore
  Courtesy of HYUNDAI MOTOR CO.
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 re-bored and honed. New oversize pistons and rings should be installed.
Standard value

Cylinder bore: 93 ~ 93.03 mm (3.661 ~ 3.6625 in.)

Out-of-round and taper of cylinder bore:

Max. 0.02 mm (0.0008 in.)
If a ridge exists at the top of the cylinder, cut it off with a ridge reamer.
Oversize pistons are available in four sizes.
Piston service size and mark mm (in.)

0.25 (0.010) O.S.: 0.25

0.50 (0.020) O.S.: 0.50
To re-bore the cylinder bore to the oversize, maintain the specified clearance between the oversize piston and the bore and make sure that all used pistons are the same oversize. The standard measurement of the piston outside diameter is taken at a level of 12 mm (0.47 in.) above the bottom of the piston skirt and across the thrust faces.
Piston - to - cylinder clearance:

0.03 ~ 0.05 mm (0.0012 ~ 0.0020 in.)

Fig 2: Identifying Piston Measuring Location
Courtesy of HYUNDAI MOTOR CO.
Check for damage or cracks in the cylinders.
Check the top surface of the cylinder block for flatness. If the top surface exceeds the limit, grind to the minimum limit or replace.
Standard value

Flatness of gasket surface:

Max. 0.03 mm (0.0012 in.)

Service limit

Flatness of gasket surface: 0.05 mm (0.0020 in.)

CAUTION: When the cylinder head is assembled, grinding less than 0.2 mm (0.008 in.) is permissible.

Fig 3: Checking Cylinder Block Top Surface Flatness
Courtesy of HYUNDAI MOTOR CO.