This plastic gauge method is recommended as a simplest way of measuring the crankshaft oil clearance.
Measure the crankshaft oil clearance using a plastic gauge as follows:

1. Wipe off oil from the crankshaft journal surface and the crankshaft bearing inner surface.

2. Install the crankshaft.

3. Cut a piece of plastic gauge whose length is equivalent to the width of the bearing and place it on the crankshaft journal in parallel with its axis.

4. Install the crankshaft bearing cap carefully and tighten the bolts to the specified torque.

5. Remove the bolts, then remove the crankshaft bearing cap carefully.

6. Measure the largest width of the crushed plastic gauge using the ruler printed on the bag of the plastic gauge.
Standard value: 0.02 - 0.04 mm

Limit: 0.1 mm

1. Visually check the cylinder block for scratches, rust, and any other corrosion. Also check it for cracks using a flaw detecting penetrant. If any defect is evident, replace the cylinder block.

2. Use a straightedge and thickness gauge to check the cylinder block top surface for warp. Make sure that the surface is free from remaining gasket material and other foreign matter.
Standard value: 0.05 mm

Limit: 0.1 mm

3. Check cylinder walls for scratches and seizure. If defects are evident, rebore to an oversize or replace the cylinder block.

4. Use a cylinder gauge to measure the cylinder bore diameter and taper. If the cylinder is worn badly, rebore it to an oversize and replace the piston and piston rings with ones that match with the new bore size.
Standard value:
4G63 85.00 mm
4G64 86.50 mm

Cylindricity 0.01 mm

1. Select an oversize of the pistons to be used based on the largest of the cylinder bores.

2. Oversize pistons are available in two oversizes: 0.50 mm and 1.00 mm. Bore each cylinder to a size that provides the standard clearance when combined with the selected piston. The reference position for piston diameter measurement is as shown in the drawing.

3. Based on the piston diameter measurement, calculate the boring finish dimension.
• Boring finish dimension =[Piston diameter]+[0.02 - 0.04 (clearance between piston and cylinder)]-[0.02 mm (honing margin)]

 CAUTION
To prevent deformation of cylinder block that would result from the heat generated by boring, bore the cylinders in the following sequence: No. 2 → No. 4 → No. 1 → No. 3.

4. Bore all the cylinders to the calculated boring finish dimension.

5. Hone the bored cylinders to the final finish dimension (piston diameter + clearance between piston and cylinder).

6. Check the clearance between the piston and cylinder.
Standard value: 0.02 - 0.04 mm