Warning.
- It is necessary to bore all four cylinders to one overall size, the value of which is greater than the maximum diameter obtained by measuring the cylinders of the block being inspected, and corresponds to the diameter of the piston of the repair (enlarged) size.
- Replacement piston rings must match the diameter of the repair piston (enlarged) size.
1. Values of piston diameters of increased (repair) sizes.
For Y series engines, the following sizes of repair pistons are used:
- + 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 bottom.
b) Calculate the size of each cylinder.
Size for boring = P+C-H
P - piston diameter.
C - clearance between piston and cylinder.
C = 0.075 - 0.095 mm for U series engines.
H - honing tolerance.
H = 0.02 mm or less.
3. Bore and hone the cylinders to the required dimensions.
The material is republished from an online website Toyotaman.ru
The feed rate of the hone per pass is 0.02 mm.
Warning: Over-honing will increase cylinder bore out-of-roundness.