Engine Block

REMOVAL
Remove the cylinder head, timing belt train, front case, flywheel, piston and crankshaft.

INSPECTION
Cylinder Block
1. Visually check the cylinder block for scores, rust and corrosion. Also check for cracks or any other defects. Correct or replace the block if defective.





2. Measure cylinder bore with a cylinder gauge at three levels in 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.
3. If cylinder bores show more than specified out-of-round or taper, or if cylinder walls are badly scuffed or scored, cylinder block should be rebored and honed, and new oversize piston and rings are fitted.
Standard value:
Cylinder bore: 85.00-85.03 mm (3.3465-3.3476 inch)
Out-of-roundness and taper of cylinder bore: Max. 0.01 mm (0.0004 inch)
4. If cylinder top ridge is worn in stages, cut away with ridge reamer.
5. Oversize pistons are available in four sizes.
Piston service
Size - mm (inch) I.D. Mark
0.25 (0.010) O.S. 0.25
0.50 (0.020) O.S. 0.50
0.75 (0.030) O.S. 0.75
1.00 (0.039) O.S. 1.00

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. The standard measurement of the piston outside diameter is taken at a level 2 mm (0.08 inch) above the bottom of the piston skirt and across the thrust faces.
Piston-to-cylinder wall clearance: 0.02-0.04 mm (0.0008-0.0012 inch)
7. Check for damage and cracks.





8. Check top surface for flatness. If excessive flatness is evident, grind to minimum limit or replace.
Standard value:
Flatness of gasket surface: Max. 0.05 mm (0.0020 inch)
Cylinder block (New) height: 284 mm (11.18 inch)
Service limit:
Flatness of gasket surface: 0.1 mm (0.0039 inch)
Overall height: -0.2 mm (-0.0079 inch)

NOTE: The cylinder block gasket surface should be ground to within -0.2 mm (-0.0079 inch) even with the grind of cylinder head gasket surface.

Boring Cylinder
1. Oversize pistons to be used should be determined on the basic of the largest bore cylinder.

NOTE: Size mark is stamped on top of piston.

2. Measure outside diameter of piston to be used.





3. Based on measured piston O.D., calculate boring finish dimension.
Boring finish dimension = Piston O.D + 0.02-0.04 mm (0.0008-0.0016 inch) (clearance between O.D and cylinder)-0.02 mm (0.008 inch) (honing margin)
4. Bore each of the cylinders to the calculated size.

NOTE: To prevent distortion that may result room temperature rise during honing, bore cylinders, working from No.2 to No.4 to No.1 to No.3.

5. Hone the cylinders, finishing them to the proper dimension (piston outside diameter + gap with cylinder).
6. Check clearance between piston and cylinder.

NOTE: When boring cylinders, finish all of four cylinders to same oversize. Do not bore only one cylinder to an oversize.

REASSEMBLY
1. Install the following parts by referring to the respective procedures.
1. Crankshaft
2. Flywheel
3. Piston
4. Cylinder head
5. Timing belt train
6. Front case