Warning.
- It is necessary to bore all four cylinders by one common size, the value of which is greater than the maximum diameter obtained by measuring the cylinders of the examined block, and corresponds to the diameter of the piston of the repair (enlarged) size.
- Replaced piston rings must match the piston diameter of the repair (enlarged) size.
1. Values of diameters of pistons increased (repair) sizes.
For Y-series engines, overhaul pistons are available in the following sizes:
- + 0.50 mm - 86.415 - 86.445 mm
- + 0.75 mm - 86.665 - 86.695 mm
- + 1.00 mm - 86.915 - 86.945 mm
2. Determine the size of the cylinders to be bored.
A) Using a micrometer, measure the piston diameter at right angles to the piston pin axis (in a plane passing through the center of the piston and perpendicular to the axis of the piston pin) at a distance of 28 mm or 24 mm from the piston crown.
b) Calculate the size of each cylinder.
Boring size = P+S-N
P is the piston diameter.
C is the gap between the piston and the cylinder.
C \u003d 0.075 - 0.095 mm for U series engines.
H - tolerance for honing.
H = 0.02 mm or less.
3. Rebore and honing the cylinders to the required dimensions.
The amount of hone feed in one pass is 0.02 mm.
Warning: Excessive honing will increase the ovality of the cylinder bore.