How to Select Piston and Bearing

How to Select Piston and Bearing

Description





*: For the service parts, the grade for fitting cannot be selected between piston pin and connecting rod. (Only (0) grade is available.) The information at the shipment from the plant is described as a reference.

- The identification grade stamped on each part is the grade for the dimension measured in new condition. This grade cannot apply to reused parts.
- For reused or repaired parts, measure the dimension accurately. Determine the grade by comparing the measurement with the values of each selection table.
- For details of the measurement method of each part, the reuse standards and the selection method of the selective fitting parts, follow the applicable procedures.

How to Select Piston

When New Cylinder Block is Used

Check the cylinder bore grade [(1), (2), or (3)] on rear side of cylinder block, and select piston of the same grade.





NOTE:

Piston is available with piston pin as a set for the service part. (Only (0) grade piston pin is available.)

When Cylinder Block is Reused

1) Measure the cylinder bore inner diameter. Refer to [Engine Unit: Inspection After Disassembly] Inspection After Disassembly.
2) Determine the bore grade by comparing the measurement with the values under the cylinder bore inner diameter of the "Piston Selection Table".





3) Select piston of the same grade.

Piston Selection Table

Unit: mm (in)






NOTE:

- Piston is available together with piston pin as assembly.
- Piston pin (piston pin hole) grade is provided only for the parts installed at the plant. For service parts, no piston pin grades can be selected. (Only (0) grade is available.)
- No second grade mark is available on piston.

How to Select Connecting Rod Bearing

When New Connecting Rod and Crankshaft are Used

Check pin journal grade [(0), (1), or (2)] on front of crankshaft, and select connecting rod bearing of the same grade.





NOTE:

There is no grading for connecting rod big end diameter.

When Crankshaft and Connecting Rod are Reused

1) Measure the connecting rod big end diameter. Refer to [Engine Unit: Inspection After Disassembly] Inspection After Disassembly.
2) Make sure that the connecting rod big end diameter is within the standard value.
3) Measure the crankshaft pin journal diameter. Refer to [Engine Unit: Inspection After Disassembly] Inspection After Disassembly.
4) Determine the grade of crankshaft pin journal grade by corresponding to the measured dimension in "Crankshaft pin journal diameter" column of "Connecting Rod Bearing Selection Table".
5) Select connecting rod bearing of the same grade.

Connecting Rod Bearing Selection Table

Unit: mm (in)






Unit: mm (in)






Undersize Bearings Usage Guide

- When the specified connecting rod bearing oil clearance is not obtained with standard size connecting rod bearings, use undersize (US) bearings.
- When using undersize (US) bearing, measure the connecting rod bearing inner diameter with bearing installed, and grind crankshaft pin so that the connecting rod bearing oil clearance satisfies the standard.

CAUTION:
In grinding crankshaft pin to use undersize bearings, keep the fillet R [1.5 - 1.7 mm (0.059 - 0.067 in)].





Bearing undersize table

Unit: mm (in)






How to Select Main Bearing

When New Cylinder Block and Crankshaft are Used

1) "Main Bearing Selection Table" rows correspond to bearing housing grade on rear left side of cylinder block.





2) "Main Bearing Selection Table" columns correspond to journal diameter grade on front side of crankshaft.





3) Select main bearing grade at the point where selected row and column meet in "Main Bearing Selection Table".

When Cylinder Block and Crankshaft are Reused

4) Measure cylinder block main bearing housing inner diameter and crankshaft main journal diameter. Refer to [Engine Unit: Inspection After Disassembly] Inspection After Disassembly and [Engine Unit: Inspection After Disassembly] Inspection After Disassembly.
5) Correspond the measured dimension in "Cylinder block main bearing housing inner diameter" row of "Main Bearing Selection Table".
6) Correspond the measured dimension in "Crankshaft main journal diameter" column of "Main Bearing Selection Table".
7) Select main bearing grade at the point where selected row and column meet in following selection table.

Main Bearing Selection Table





Main Bearing Grade Table (All Journals)






Undersize Bearing Usage Guide

- When the specified main bearing oil clearance is not obtained with standard size main bearings, use underside (US) bearing.
- When using undersize (US) bearing, measure the main bearing inner diameter with bearing installed, and grind main journal so that the main bearing oil clearance satisfies the standard.

CAUTION:
In grinding crankshaft main journal to use undersize bearings, keep the fillet R [1.5 - 1.7 mm (0.059 - 0.067 in)].





Bearing undersize table

Unit: mm (in)