Piston: Specifications
PISTON TO PISTON PIN OIL CLEARANCEPiston Pin Hole Diameter
Measure the inner diameter of piston pin hole with inside micrometer.
Standard: 21.993 - 22.005 mm (0.8659 - 0.8663 inch)
Piston Pin Outer Diameter
Measure the outer diameter of piston pin with micrometer.
Standard: 21.989 - 22.001 mm (0.8657 - 0.8662 inch)
Piston to Piston Pin Oil Clearance
(Piston to piston pin oil clearance) = (Piston pin hole diameter) - (Piston pin outer diameter)
Standard: 0.002 - 0.006 mm (0.0001 - 0.0002 inch)
^ If the calculated value is out of the standard, replace piston and piston pin assembly.
^ When replacing piston and piston pin assembly, refer to HOW TO SELECT PISTON. How to Select Piston and Bearing
NOTE:
^ Piston is available together with piston pin as assembly
^ Piston pin (piston pin hole) grade is provided only for the parts installed at the plant. For service parts, no piston pin grades can be selected. (Only 0 grade is available.)
PISTON TO CYLINDER BORE CLEARANCE
Cylinder Bore Inner Diameter
Using bore gauge, measure 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) (X is in longitudinal direction of engine)
Standard inner diameter: 93.000 - 93.030 mm (3.6614 - 3.6626 inch)
Wear limit: 0.2 mm (0.008 inch)
Out-of-round (Difference between X and Y): 0.015 mm (0.0006 inch)
Taper limit (Difference between A and C): 0.01 mm (0.0004 inch)
^ If the measured value exceeds the limit, or if there are scratches and/or seizure on the cylinder inner wall, hone or re-bore the inner wall.
^ Oversize piston is provided. When using oversize piston, rebore cylinder so that the clearance of the piston-to-cylinder bore satisfies the standard.
CAUTION: When using oversize piston, use oversize pistons for all cylinders with oversize piston rings.
Oversize (OS): 0.2 mm (0.008 inch)
Piston Skirt Diameter
^ Measure the outer diameter of piston skirt with micrometer.
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 piston skirt diameter and cylinder bore inner diameter (direction Y position B). (Clearance) = (Cylinder bore inner diameter) - (Piston skirt diameter).
Standard: 0.010 - 0.030 mm (0.0004 - 0.0012 inch)
Limit: 0.08 mm (0.0031 inch)
^ If the calculated value exceeds the limit, replace piston and piston pin assembly.
Re-boring Cylinder Bore
1. Cylinder bore size is determined by adding piston to cylinder bore clearance to piston skirt diameter.
^ Re-bored size calculation: D = A + B - C where, D: Bored diameter A: Piston skirt diameter as measured B: Piston to cylinder bore clearance (standard value) C:
Honing allowance: 0.02 mm (0.0008 inch)
2. Install main bearing caps and main bearing, 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.
^ 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 the specified piston to cylinder bore clearance.
5. Measure finished cylinder bore for the out-of-round and taper.
NOTE: Measurement should be done after cylinder bore cools down.
PISTON, PISTON RING AND PISTON PIN
Available Piston:
Available Piston
Piston Ring:
Piston Ring
Piston Pin:
Piston Pin