Service Limits & General Specifications
CRANKSHAFT SIDE CLEARANCE
^ Using a dial gauge, measure the clearance between the thrust bearings and the crankshaft arm when the crankshaft is moved fully forward or backward.
Standard: 0.10 - 0.26 mm (0.0039 - 0.0102 inch)
Limit: 0.30 mm (0.0118 inch)
^ If the measured value exceeds the limit, replace the thrust bearings, and measure again. If it still exceeds the limit, replace the crankshaft.
CONNECTING ROD SIDE CLEARANCE
^ Measure side clearance between connecting rod and crankshaft arm with feeler gauge.
Standard: 0.20 - 0.35 mm (0.0079 - 0.0138 inch)
Limit: 0.50 mm (0.0197 inch)
^ If the measured value exceeds the limit, replace the connecting rod bearings, and measure again. If it still exceeds the limit, replace the crankshaft also.
PISTON AND PISTON PIN CLEARANCE
Piston Pin Bore Diameter
^ Measure the piston pin bore diameter with an inside micrometer.
^ Service parts apply only to grade 0.
Piston pin bore diameter
Grade No. 0: 19.993 - 19.999 mm (0.7871 - 0.7874 inch)
Grade No.1: 19.999 - 20.005 mm (0.7874 - 0.7876 inch)
Outer Diameter of Piston Pin
^ Measure outer diameter of piston pin with a micrometer.
Piston pin outer diameter
Grade No. 0: 19.989 - 19.995 mm (0.7870 - 0.7872 inch)
Grade No.1: 19.995 - 20.001 mm (0.7872 - 0.7874 inch)
Piston to Piston Pin Clearance
(Piston to piston pin clearance) = (Piston pin bore diameter) - (Outer diameter of piston pin)
Standard: 0.002 - 0.006 mm (0.0001 - 0.0002 inch)
If clearance exceeds specification, replace either or both of piston/piston pin assembly and connecting rod assembly with reference to specification of each parts.
^ Refer to piston selection table to replace piston/piston pin assembly. Refer to HOW TO SELECT A PISTON.
^ Refer to connecting rod bearing selection table to replace connecting rod. Refer to HOW TO SELECT A CONNECTING ROD BEARING.
NOTE:
^ The connecting rod small end grade and piston pin hole (piston pin) grade are provided only for the parts installed at the plant. For service parts, no grades can be selected. Only 0 grade is available.
^ Refer to CONNECTING ROD BUSHING OIL CLEARANCE (SMALL END) for the values for each grade at the plant.
^ Regarding marks on piston head, refer to HOW TO SELECT A PISTON.
PISTON RING SIDE CLEARANCE
^ Measure side clearance of piston ring and piston ring groove with feeler gauge.
Standard
Top ring: 0.040 - 0.080 mm (0.0016 - 0.0031 inch)
2nd ring: 0.030 - 0.070 mm (0.0012 - 0.0028 inch)
Oil ring: 0.065 - 0.135 mm (0.0026 - 0.0053 inch)
Limit Top ring: 0.11 mm (0.0043 inch)
2nd ring: 0.10 mm (0.004 inch)
Oil ring: -
^ If out of specification, replace piston and/or piston ring assembly.
PISTON RING END GAP
^ Check if inner diameter of cylinder bore is within specification.
Refer to PISTON TO CYLINDER BORE CLEARANCE.
^ Insert piston ring until middle of cylinder with piston, and mea sure gap.
Standard
Top ring: 0.21 - 0.31 mm (0.0083 - 0.0122 inch)
2nd ring: 0.32 - 0.47 mm (0.0126 - 0.0185 inch)
Oil ring: 0.20 - 0.60 mm (0.0079 - 0.0236 inch)
Limit
Top ring: 0.54 mm (0.0213 inch)
2nd ring: 0.67 mm (0.0264 inch)
Oil ring: 0.95 mm (0.0374 inch)
^ If out of specification, replace piston ring. If gap still exceeds the limit even with a new ring, re-bore cylinder and use oversized piston and piston ring.
CONNECTING ROD BEND AND TORSION
^ Check with connecting rod aligner.
Bend limit: 0.15 mm (0.0059 inch) per 100 mm (3.94 inch) length
Torsion limit: 0.30 mm (0.0118 inch) per 100 mm (3.94 inch) length
^ If it exceeds the limit, replace connecting rod assembly.
CONNECTING ROD BEARING (BIG END)
^ Install the connecting rod cap without the connecting rod bearing installed. After tightening the connecting rod bolt to the specified torque, measure the connecting rod big end inner diameter using an inside micrometer.
Standard: 48.000 - 48.013 mm (1.8898 - 1.8903 inch)
CYLINDER BLOCK DISTORTION
^ Using a scraper, remove gasket on the cylinder block surface, and also remove oil, scale, carbon, or other contamination.
CAUTION: Be careful not to allow gasket debris to enter the oil or coolant passages.
^ Measure the distortion on the block upper face at some different points in 6 directions.
Limit: 0.1 mm (0.004 inch)
^ If out of the distortion limit, replace the cylinder block.
INNER DIAMETER OF MAIN BEARING HOUSING
Install the lower cylinder block with the main bearings removed and tighten the mounting bolts to the specified torque. Refer to ASSEMBLY.
^ Using a bore gauge, measure the inner diameter of the main bearing housing. Refer to CYLINDER BLOCK.
^ If out of the standard, replace the cylinder block and lower cylinder block assembly.
NOTE: These components cannot be replaced as a single unit because they were processed together.
PISTON TO CYLINDER BORE CLEARANCE
Inner Diameter of Cylinder Bore
^ Using a bore gauge, measure cylinder bore for wear, out-of-round and taper at 6 different points on each cylinder. (X and Y directions at A, B and C). The Y axis is in the longitudinal direction of the engine.
NOTE: When determining cylinder bore grade, measure cylinder bore at B position.
Cylinder bore inner diameter
Grade No.1: 89.000 - 89.010 mm (3 5039 - 3.5043 inch)
Grade No. 2: 89.010 - 89.020 mm (3 5043 - 3.5047 inch)
Grade No. 3: 89.020 - 89.030 mm (3.5047 - 3.5051 inch)
Wear limit: 0.2 mm (0.008 inch)
Out-of-round 0.015 mm (0.0006 inch) (difference between, X - Y):
Taper limit (difference 0.01 mm (0.0004 inch) between, C - A):
^ If the measured value rebore exceeds the limit, or if there are scratches and/or seizure on the cylinder inner wall, hone the inner wall.
^ An oversize piston is provided. When using an oversize piston, rebore the cylinder so that the clearance of the piston cylinder satisfies the standard.
Piston oversize (OS)
Clearance: 0.2 mm (0.008 inch)
Diameter: 89.180 - 89.210 mm (3.5110 - 3.5122 inch)
Outer Diameter of Piston
^ Measure piston skirt diameter (A).
Piston skirt diameter
Grade No.1: 88.980 - 88.990 mm (3.5031 - 3.5035 inch)
Grade No. 2: 88.990 - 89.000 mm (3.5035 - 3.5039 inch)
Grade No. 3: 89.000 - 89.010 mm (3.5039 - 3.5043 inch)
Oversize 0.20 mm (0.0079 inch) clearance
^ Measure point (a) (distance from the top): 42 mm (1.65 inch)
Piston to Cylinder Bore Clearance
^ Calculate by outer diameter of piston skirt and inner diameter of cylinder (direction X, position B). (Clearance) = (Inner diameter of cylinder) - (Outer diameter of piston skirt).
Standard: 0.010 - 0.030 mm (0.0004 - 0.0012 inch)
Limit: 0.08 mm (0.0031 inch)
^ If it exceeds the limit, replace piston/piston pin assembly.
Reboring Cylinder Bore
1. Cylinder bore size is determined by adding piston-to-bore clearance to piston diameter A.
Rebored size calculation: D = A + B - C
D: Bored diameter
A: Piston diameter as measured
B: Piston-to-bore clearance (standard value)
C: Honing allowance 0.02 mm (0.0008 inch)
2. Install main bearing caps, and tighten to the specified torque. Otherwise, cylinder bores may be distorted in final assembly.
3. Cut cylinder bores.
NOTE: When any cylinder needs boring, all other cylinders must also be bored.
CAUTION: Do not cut too much out of cylinder bore at a time. Cut only 0.05 mm (0.0020 inch) or so in diameter at a time.
4. Hone cylinders to obtain specified piston-to-bore clearance.
5. Measure finished cylinder bore for out-of-round and taper.
NOTE: Measurement should be done after cylinder bore cools down.
OIL CLEARANCE OF CONNECTING ROD BEARING
Method of Measurement
Install the connecting rod bearings to the connecting rod and the cap, and tighten the connecting rod bolts to the specified torque. Using an inside micrometer measure the inner diameter of connecting rod bearing.
(Oil clearance) = (Inner diameter of connecting rod bearing) (Outer diameter of crankshaft pin)
Standard: 0.028 - 0.045 mm (0.0011 - 0.0018 inch)
Limit: 0.10 mm (0.0039 inch)
^ If clearance cannot be adjusted within the standard, grind crankshaft pin and use undersized bearing. Refer to HOW TO SELECT A CONNECTING ROD BEARING.
Method of Using Plastigage
Remove oil and dust on the crankshaft pin and the surfaces of each bearing completely.
^ Cut the Plastigage slightly shorter than the bearing width, and place it in crankshaft axial direction, avoiding oil holes.
^ Install the connecting rod bearings to the connecting rod cap, and tighten the connecting rod bolts to the specified torque.
CAUTION: Never rotate the crankshaft.
^ Remove the connecting rod cap and bearings, and using the scale on the Plastigage bag, measure the Plastigage width.
NOTE: The procedure when the measured value exceeds the limit is same as that described in the method by calculation.
OIL CLEARANCE OF MAIN BEARING
Method of Measurement
^ Install the main bearings to the cylinder block and lower cylinder block. Measure the main bearing inner diameter with the lower cylinder block bolts tightened to the specified torque. (Oil clearance) = (Inner diameter of main bearing) - (Outer diameter of crankshaft journal)
Standard:
No. 1, 3, and 5 journals: 0.012 - 0.022 mm (0.0005 - 0.0009 inch)
No. 2 and 4 journals: 0.018 - 0.028 mm (0.0007 - 0.0011 inch)
Limit: 0.1 mm (0.004 inch)
^ If the measured value exceeds the limit, select main bearings referring to the main bearing inner diameter and crankshaft journal outer diameter, so that the oil clearance satisfies the standard. Refer to HOW TO SELECT A MAIN BEARING.
Method of Using Plastigage
Remove oil and dust on the crankshaft journal and the surfaces of each bearing completely.
^ Cut the Plastigage slightly shorter than the bearing width, and place it in crankshaft axial direction, avoiding oil holes. Tighten the main bearing bolts to the specified torque.
CAUTION: Never rotate the crankshaft.
^ Remove the bearing cap and bearings, and using the scale on the Plastigage bag, measure the Plastigage width.
NOTE: The procedure when the measured value exceeds the limit is same as that described in the Method by Calculation.
CRUSH HEIGHT OF MAIN BEARING
When the bearing cap is removed after being tightened to the specified torque with main bearings installed, the tip end of bearing must protrude.
Standard: There must be crush height.
^ If the standard is not met, replace main bearings.
OUTER DIAMETER OF LOWER CYLINDER BLOCK MOUNTING BOLT
^ Perform only with M10 (0.39 inch) bolts.
^ Measure outer diameters (d1, d2) at two positions as shown.
^ Measure d2 at a point within block A.
^ When the value of d1 - d2 exceeds the limit (a large difference in dimensions), replace the bolt with a new one.
Limit: 0.13 mm (0.0051 inch) or more
OUTER DIAMETER OF CONNECTING ROD BOLT
^ Measure outer diameter (d) at position shown. When d exceeds the limit (when it becomes thinner), replace the bolt with a new one.
Limit: 7.75 mm (0.3051 inch) or less
Part 1:
Part 2:
CYLINDER BLOCK