How to Select Piston and Bearing

CYLINDER BLOCK


How to Select Piston and Bearing


DESCRIPTION





- 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, refer to the text.

HOW TO SELECT PISTON

When New Cylinder Block is Used
Check the cylinder bore grade ("1", "2" or "3") on the rear upper side between cylinder block banks, 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 Inspection After Disassembly.





2. Determine the bore grade by comparing the measurement with the values the "Cylinder bore inner diameter" of the "Piston Selection Table". Select piston of the same grade.

Piston Selection Table






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 diameter 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 Inspection After Disassembly.
2. Check that the connecting rod big end diameter is within the standard value.
3. Measure the crankshaft pin journal diameter. Refer to Inspection After Disassembly.
4. Determine the grade of crankshaft pin diameter 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









Under Size 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 mm (0.059 in)].











HOW TO SELECT MAIN BEARING

When New Cylinder Block and Crankshaft are Used
1. "Main Bearing Selection Table" rows correspond to main bearing housing grade on rear upper side between cylinder block banks.





2. "Main Bearing Selection Table" columns correspond to main journal diameter grade on front side of crankshaft.
3. Select main bearing grade at the point where selected row and column meat in "Main Bearing Selection Table".





CAUTION:
- Initial clearance for No. 1, 5 journal and No. 2, 3, 4 journal is different. Use two different selection table for each part.
- No. 1, 5 journal and No. 2, 3, 4 journal have the same signs but different measures. Never confuse.
4. Apply sign at crossing in above step 3 to "Main Bearing Grade Table".

NOTE:
- "Main Bearing Grade Table" applies to all journals.
- Service parts is available as a set of both upper and lower.

When Cylinder Block and Crankshaft are Reused
1. Measure the cylinder block main bearing housing inner diameter and the crankshaft main journal diameter. Refer to Inspection After Disassembly.
2. Correspond the measured dimension in "Cylinder block main bearing housing inner diameter" row of "Main Bearing Selection Table".
3. Correspond the measured dimension in "Crankshaft main journal diameter" column of "Main Bearing
Selection Table".
4. Follow step 3 and later in "When New Cylinder Block and Crankshaft are Used".

Main Bearing Selection Table (No. 1 and 5 Journal)






Main Bearing Selection Table (No. 2, 3 and 4 Journal)






Main Bearing Grade Table (All Journals)










Use 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 mm (0.059 in)].