Piston, Engine
PISTON AND PISTON PIN CLEARANCEPiston Pin Hole Diameter
^ Measure diameter of piston pin hole using suitable tool.
Standard: 21.993 - 21.999 mm (0.8659 - 0.8661 in)
Piston Pin Diameter
^ Measure diameter of piston pin using suitable tool.
Standard: 21.989 - 21.995 mm (0.8657 - 0.8659 in)
Piston and Piston Pin Clearance
(Piston pin clearance) = (Piston pin hole diameter) - (Piston pin diameter)
Standard: 0.002 - 0.006 mm (0.0001 - 0.0002 in)
^ If clearance exceeds specification, replace either or both the piston/piston pin assembly and the connecting rod assembly with reference to the specification of each part.
^ Refer to the piston selection table to replace piston/piston pin assembly.
^ Refer to the connecting rod bearing selection table to replace connecting rod.
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 EM-96, "CONNECTING ROD BUSHING OIL CLEARANCE (SMALL END)" for the values for each grade at the plant. Service Limits & General Specifications
PISTON TO CYLINDER BORE CLEARANCE
Cylinder Bore Diameter
^ Measure the cylinder bore for wear, out-of-round and taper at six different points on each cylinder ("X" and "Y" directions at "A", "B" and "C").
NOTE: When determining cylinder bore grade, measure cylinder bore at "B" position.
Standard diameter: 98.000 - 98.030 mm (3.8583 - 3.8594 in)
Wear limit: 0.20 mm (0.0079 in)
Out-of-round (Difference between "X" and "Y"):
Limit: 0.015 mm (0.0006 in)
Taper limit (Difference between "A" and "C"):
Limit: 0.010 mm (0.0004 in)
^ If measured value exceeds the repair limit, or if there are scratches and/or seizure on the cylinder inner wall, hone or bore the inner wall.
^ An oversize piston is provided. When using an oversize piston, hone the cylinder so that the clearance between the piston and cylinder satisfies the standard.
Piston oversize Grade No. 0 (Service): 0.20 mm (0.0079 in)
^ If oversize piston is used, use it for all cylinders with oversize piston rings.
Piston Skirt Diameter
^ Measure piston skirt diameter using suitable tool.
Standard: 97.980 - 98.010 mm (3.8575 - 3.8587 in)
^ Measure point "H".
Distance from the top: 39 mm (1.54 in)
Piston to Cylinder Bore Clearance
^ Calculate by using diameter of the piston skirt and the cylinder bore diameter (direction X, position B). (Clearance) = (Cylinder bore diameter) - (piston skirt diameter)
Standard: 0.010 - 0.030 mm (0.0004 - 0.0012 in)
Limit: 0.08 mm (0.0031 in)
^ If calculation 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
where,
D: Bored diameter
A: Piston diameter as measured
B: Piston - to - bore clearance (standard value)
C: Honing allowance 0.02 mm (0.0008 in)
2. Install main bearing caps, and tighten them to the specified torque. Otherwise, cylinder bores may be distorted in final assembly.
3. Cut the cylinder bores.
NOTE:
^ When any cylinder needs boring, all other cylinders must also be bored.
^ Do not cut too much out of cylinder bore at one time. Cut only 0.05 mm (0.0020 in) or so in diameter at a time.
4. Hone cylinders to obtain the 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.
PISTON, PISTON RING AND PISTON PIN
Available Piston
Piston Ring
Piston Pin