Piston and Piston Pin Interference Fit
Standard Interference Fit = (Dp) - (dp)
Standard : 0.002 - 0.010 mm (0.0001 - 0.0004 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.
Install the connecting rod cap without the connecting rod bearing installed. After tightening the connecting rod nut to the specified torque, measure the connecting rod bearing housing big end inner diameter using an inside micrometer.
Standard : 55.000 - 55.013 mm (2.1654 - 2.1659 in)
Connecting Rod Bushing Oil Clearance (Small End)
(Connecting rod small end oil clearance) = (Inner diameter of connecting rod small end) - (Outer diameter of piston pin)
If the measured value exceeds the standard, replace the connecting rod assembly and/or piston and piston pin assembly.
If replacing the piston and piston pin assembly, use the Table for Selective Fitting for Piston to select the piston corresponding to the applicable bore grade of the cylinder block to be used. Follow the
"PISTON-TO-CYLINDER BORE CLEARANCE" procedure. Factory installed parts grading:
Pin Grade No. (F) Service parts apply only to grade 0.
CYLINDER BLOCK DISTORTION
Using a scraper, remove any old gasket material on the cylinder block surface, and remove any oil, scale, carbon, or other contamination.
CAUTION: Be careful not to allow gasket flakes to enter the oil or coolant passages.
Measure the distortion on the block upper face at different points in six directions.
Distortion limit : 0.10 mm (0.0039 in)
If out of specification, resurface the cylinder block. The allowable amount of resurfacing is dependent on the amount of any cylinder head resurfacing. The resurfacing limit is [amount of cylinder head resurfacing] + [amount of cylinder head resurfacing] = 0.2 mm (0.008 in) .
Using a bore gauge, measure cylinder bore for wear, out-of-round and taper at (A), (B) and (C). The X axis is in the longitudinal direction of the engine.
If it exceeds the limit, rebore all cylinders. Replace cylinder block if necessary.
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.
Measure piston skirt diameter.
Check that piston-to-bore clearance is within specification.
Piston-to-bore clearance at (B) : 0.010 - 0.030 mm (0.0004 - 0.0012 in)
The piston-to-bore clearance is measured at the (B) level in the cylinder as shown.
Cylinder bore size is determined by adding piston-to-bore clearance to piston diameter (A).
Install main bearing caps, and tighten to the specified torque. Otherwise, cylinder bores may be distorted after boring.
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.
Hone cylinders to obtain specified piston-to-bore clearance.
Measure finished cylinder bore for out-of-round and taper.
Measurement should be done after cylinder bore cools down.
Place a V-block on a precise flat table to support the journals on the both ends of the crankshaft.
Place a dial gauge straight up on the No. 3 journal.
While rotating the crankshaft, read the movement of the pointer on the dial gauge.
Runout limit (total indicator reading) : 0.10 mm (0.0039 in)
BEARING CLEARANCE
Use either of the following two methods, however method (A) gives more reliable results and so is the preferred method.
Method A (Using Bore Gauge and Micrometer) Main Bearing
Set the main bearings in their proper positions on the cylinder block and the main bearing cap.
Install the main bearing caps and bearing beam to the cylinder block. Tighten all bolts in the numerical order as specified. Refer to See: Disassembly And Assembly.
Measure the inner diameters (A) of each main bearing as shown.
Measure the outer diameters (Dm) of each crankshaft main journal as shown.
Calculate the main bearing clearance.
Main bearing clearance = (A) - (Dm)
If it exceeds the limit, replace the bearing.
If clearance cannot be adjusted using any standard bearing grade, grind crankshaft journal and use an undersized bearing.
When grinding the crankshaft journal, confirm that the (L) dimension in the fillet role is more than the specified limit.
(L) : 0.10 mm (0.0039 in)
If the crankshaft or the cylinder block is replaced with a new one, select thickness of the main bearings as follows:
The grade number of each cylinder block main journal is punched on the respective cylinder block. These numbers are punched in either Arabic or Roman numerals. If measured diameter is out of the grade punched, decide suitable grade from available main bearings.
The grade number of each crankshaft main journal is punched on the crankshaft end. These numbers are punched in either Arabic or Roman numerals. If measured diameter is out of grade punched, decide the suitable grade from available main bearings.
Select the main bearing suitable thickness according to the following table:
