Piston, Engine
PISTON AND PISTON PIN CLEARANCEInner Diameter of Piston Pin
Measure the inner diameter of piston pin bore with an inside micrometer.
Standard: 21.993 - 22.005 mm (0.8659 - 0.8663 inch)
Outer Diameter of Piston Pin
Measure outer diameter of piston pin with a micrometer.
Standard: 21.989 - 22.001 mm (0.8657 - 0.8662 inch)
Piston and Piston Pin Clearance
(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 is 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 PISTON".
^ Refer to connecting rod bearing selection table to replace connecting rod. Refer to "HOW TO SELECT 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.
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)
NOTE: When determining cylinder bore grade, measure cylinder bore at B position.
Standard inner diameter: 93.000 - 93.030 mm (3.6614 - 3.6626 inch)
Wear limit: 0.20 mm (0.0079 inch)
Out-of-round (Difference between X and Y): Less than 0.015 mm (0.0006 inch)
Taper limit (Difference between A and C): Less than 0.010 mm (0.0004 inch)
^ If the 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.
Oversize (OS): 0.2 mm (0.008 inch)
^ If oversize piston is used, use it for all cylinders with oversize piston rings.
Outer Diameter of Piston
^ Measure piston skirt diameter.
Standard: 92.980 - 93.010 mm (3.6606 - 3.6618 inch)
^ Measure point "H"(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
where,
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.
^ When any cylinder needs boring, all other cylinders must also be bored.
^ 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.
^ Measurement should be done after cylinder bore cools down.
PISTON, PISTON RING AND PISTON PIN
Available Piston
Piston Ring
Piston Pin