Piston, Engine
PISTON AND PISTON PIN CLEARANCEInner Diameter of Piston Pin Hole
^ Measure the inner diameter of piston pin hole "dp".
Standard diameter "dp"
Grade No. 0: 21.989 - 21.995 mm (0.8657 - 0.8659 in)
Grade No. 1: 21.995 - 22.001 mm (0.8659 - 0.8662 in)
Outer Diameter of Piston Pin
^ Measure outer diameter of piston pin "Dp".
Standard diameter "Dp"
Grade No. 0: 21.989 - 21.995 mm (0.8657 - 0.8659 in)
Grade No. 1: 21.995 - 22.001 mm (0.8659 - 0.8662 in)
Piston and Piston Pin Interference Fit
Standard Interference Fit = "Dp" - "dp"
Standard: 0.002 mm (0.0001 in) - 0.006 mm (0.0002 in) = - 0.0004 mm (-0.0001 in)
^ If clearance is exceeds specification, replace either or both of piston/piston pin assembly and connecting rod assembly with reference to specification of each part.
PISTON-TO-CYLINDER BORE CLEARANCE
1. Using a bore gauge, measure cylinder bore for wear, out-of-round and taper. The X axis is in the longitudinal direction of the engine.
Cylinder bore inner diameter:
If it exceeds the limit, rebore all cylinders. Replace cylinder block if necessary.
Out-of-round (Difference between X and Y): limit 0.015 mm (0.0006 in)
Taper (Difference between A and C): limit 0.015 mm (0.0006 in)
2. Check for scratches and seizure. If seizure is found, hone it.
^ If both cylinder block and piston are replaced with new ones, select piston of the same grade number punched on cylinder block rear position. These numbers are punched in either Arabic or Roman numerals.
3. Measure piston skirt diameter.
Measuring point "a" (Distance from the top): 41.0 mm (1.614 in)
4. Check that piston-to-bore clearance is within specification.
Piston-to-bore: 0.010 - 0.030 mm (0.0004 - 0.0012 in) clearance at "B"
^ The piston-to-bore clearance is measured at the "B" level in the cylinder as shown.
5. Determine piston oversize according to amount of cylinder wear.
Oversize pistons are available for service.
6. 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
C: Honing allowance 0.02 mm (0.0008 in)
7. Install main bearing caps, and tighten to the specified torque. Otherwise, cylinder bores may be distorted after boring.
8. 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 in) or so in diameter at a time.
9. Hone cylinders to obtain specified piston-to-bore clearance.
10. 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