Part 2
Cylinder Block ContinuedASSEMBLY
1. Apply oil to the surfaces of the connecting rod bearings. Install the connecting rod bearings on connecting rods and connecting rod caps.
2. Install the connecting rod on crankshaft.
NOTE: Position each connecting rod with the marking side facing forward.
3. Install the connecting rod cap. Make sure the arrow mark on connecting rod cap facing front during installation.
CAUTION:
^ Each connecting rod has its own mating cap. Make sure that they are assembled correctly by checking their matching number.
^ When tightening the connecting rod bolts, apply oil on the threads and flange end.
4. Install the oil ring spacer, upper rail and lower rail in this order by hand. Install the second ring and top ring using piston ring expander.
INSPECTION
CYLINDER BLOCK
1. Visually check for cracks and damage. Especially, inspect the important parts using liquid penetrant tester.
2. Check the oil passages for clogging.
3. Inspect the crankcase surface that mates with cylinder head for warping by using a straight edge.
Standard height of cylinder block: 202 mm (7.95 inch)
CYLINDER AND PISTON
1. The cylinder bore size is stamped on the front upper face of the cylinder block.
NOTE:
^ Measurement should be performed at a temperature of 20°C (68°F).
^ Standard sized pistons are classified into two grades, A and B. These grades should be used as guide lines in selecting a standard piston.
2. How to measure the inner diameter of each cylinder: Measure the inner diameter of each cylinder in both the thrust and piston pin directions at the heights as shown in the figure, using a cylinder bore gauge.
NOTE: Measurement should be performed at a temperature of 20°C (68°F).
3. When the piston is to be replaced due to general or cylinder wear, determine a suitable sized piston by measuring the piston clearance.
4. How to measure the outer diameter of each piston: Measure the outer diameter of each piston at the height as shown in the figure. (Thrust direction)
NOTE: Measurement should be performed at a temperature of 20°C (68°F).
5. Calculate the clearance between cylinder and piston.
NOTE: Measurement should be performed at a temperature of 20°C (68°F).
20 Cylinder to piston clearance at 20°C (68°F):
Standard -0.010 - 0.010 mm (-0.00039 - 0.00039 inch)
6. Boring and honing:
a. If the value of cylindricality, out-of-roundness, or cylinder-to-piston clearance measured is out of standard or if there is any damage on the cylinder wall, rebore it to use an oversize piston.
CAUTION: When any of the cylinders needs reboring, all other cylinders must be bored at the same time, and use oversize pistons. Do not perform boring on one cylinder only. Nor use an oversize piston for one cylinder only.
b. If the cylinder inner diameter exceeds 89.715 mm (3.5321 inch) after boring and honing, replace the crankcase.
NOTE: Immediately after reboring, the cylinder diameter may differ from its real diameter due to temperature rise. Thus, pay attention to this when measuring the cylinder diameter.
PISTON AND PISTON PIN
1. Check the pistons and piston pins for damage, cracks and wear, and the piston ring grooves for wear and damage. Replace if faulty.
2. Measure the piston-to-cylinder clearance at each cylinder. If any of the clearances is not within standard, replace the piston or bore the cylinder to use an oversize piston.
3. Make sure that the piston pin can be inserted into the piston pin hole with a thumb at 20°C (68°F). Replace if faulty.
Standard clearance between piston pin and hole in piston:
4. Check the snap ring installation groove (A) on the piston for burr. If necessary, remove burr from the groove so that the piston pin can lightly move.
5. Check the piston pin snap ring for distortion, cracks and wear.
PISTON RING
1. If the piston ring is broken, damaged or worn, or if its tension is insufficient, or when the piston is replaced, replace the piston ring with a new one of the same size as piston.
CAUTION:
^ Marks are displayed on the end of top and second rings. When installing the ring to piston, face this mark upward.
^ Oil ring consists of the upper rail, expander and lower rail. When installing on the piston, be careful of the direction of each rail
2. Squarely place the piston ring and oil ring in cylinder, and measure the piston ring gap with a thickness gauge.
3. Measure the clearance between piston ring and piston ring groove with a thickness gauge.
NOTE: Before measuring the clearance, clean the piston ring groove and piston ring.
CONNECTING ROD
1. Replace the connecting rod, if the large or small end thrust surface is damaged.
2. Check for bend or twist using a connecting rod aligner. Replace the connecting rod if it has the bend or twist.
3. Install the connecting rod fitted with bearing to crankshaft and measure the thrust clearance. If the clearance exceeds the standard or offset wear occurs, replace the connecting rod.
4. Inspect the connecting rod bearing for scar, peeling, seizure, melting, wear, etc.
5. Measure the oil clearance on each connecting rod bearing using plastigauge. If any oil clearance is not within the standard, replace the defective bearing with a new one of standard size or undersize as necessary. (See the table below.)
6. Inspect the bushing at connecting rod small end, and replace if worn or damaged. Also measure the piston pin clearance at connecting rod small end.
7. Replacement procedure is as follows.
a. Remove the bushing from connecting rod with ST and press.
b. Press the bushing with ST after applying oil on the periphery of bushing.
ST 18350AA000 CONNECTING ROD BUSHING REMOVER & INSTALLER
c. Make two 3 mm (0.12 inch) holes in bushing. Ream the inside of bushing.
d. After completion of reaming, clean the bushing to remove chips.
CRANKSHAFT AND CRANKSHAFT BEARING
1. Clean the crankshaft completely, and check it for cracks using liquid penetrant tester. Replace if defective.
2. Check the crankshaft for bend, and repair or replace if needed. Repair or replace if bended.
NOTE: If a suitable V-block is not available, install #1 and #5 crankshaft bearing on cylinder block, position the crankshaft on these bearings, and then check the crankshaft bend using a dial gauge.
3. Inspect the crank journal and crank pin for wear. If they are not within the specification, replace the bearing with a suitable (undersize) one, and replace or readjust crankshaft as necessary. When grinding the crank journal or crank pin, finish them to the specified dimensions according to the undersize bearing to be used.
4. Measure the thrust clearance of crankshaft at center bearing. If clearance exceeds the standard, replace the bearing.
5. Inspect individual crankshaft bearings for signs of flaking, seizure, melting and wear.
6. Measure the oil clearance on each crankshaft bearing using plastigauge. If the measured value is out of standard, replace the defective bearing with an undersize one, and replace or recondition the crankshaft as necessary.
Crankshaft oil clearance:
Standard 0.010 - 0.030 mm (0.0004 - 0.0012 inch)