Cleaning and Inspection
INSPECTIONCrankshaft Journal Oil Clearance
The crankshaft oil clearance can be measured easily by using a Plastigage, as follows.
1. Remove oil and grease and any other foreign material from the crankshaft journal and bearing inner surface.
2. Install the crankshaft.
3. Cut the Plastigage to the same length as the width of the bearing and place it on the journal in parallel with its axis.
4. Gently place the crankshaft bearing cap over it and tighten the bolts to the specified torque.
5. Remove the bolts and gently remove the crankshaft bearing cap.
6. Measure the width of the smashed Plastigage at its widest section by using a scale printed on the Plastigage bag.
Standard value: 0.02-0.04 mm (0.0008-0.0016 inch)
Limit: 0.1 mm (0.004 inch)
Cylinder Block
1. Visually check for scratches, rust and corrosion. Use also a flaw detecting agent for the check. If defects are evident, correct, or replace.
2. Using a straight edge and feeler gauge, check the block top surface for warpage. Make sure that the surface is free from gasket chips and other foreign matter.
Standard value: 0.05 mm (0.0020 inch)
Limit: 0.1 mm (0.004 inch)
3. If the distortion is excessive, correct within the allowable limit or replace.
Grinding limit: 0.2 mm (0.008 inch)
The total thickness of the stock allowed to be removed from cylinder block and mating cylinder head is 0.2 mm (0.008 inch) at maximum.
4. Check cylinder walls for scratches and seizure. If defects are evident, correct (bored to oversize) or replace.
5. Using cylinder gauge, measure the cylinder bore and cylindricity. If worn badly, correct cylinder to an oversize and replace piston and piston rings. Measure at the points shown in illustration.
Standard value: Cylinder I.D. 83.50-83.53 mm (3.2874-3.2886 inch) Cylindricity: 0.01 mm (0.0004 inch)
Cylinder Boring
1. Determine the oversize piston on the basis of the largest bore cylinder.
2. Two types of oversize pistons (0.50 mm and 1.00 mm) are available. The standard measuring points for the piston outside diameter are at the positions shown in the illustration.
3. Based on the measured piston outside diameter, calculate the boring finish dimension. [Boring finish dimension] = [Piston outside diameter] + [0.02-0.04 mm (0.0008-0.0016 inch) clearance to cylinder]-[0.02 mm (0.0008 inch) honing margin]
4. Bore each cylinder to the calculated boring finish dimension.
5. Hone to the final finish dimension (piston outside diameter + clearance between piston outside diameter and cylinder).
6. Check the piston to cylinder clearance.
Standard value: 0.02-0.04 mm (0.0008-0.0016 inch)