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 grade "0" 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 on rear-left side of cylinder block, and select piston of the same grade.
- If there is a corrected stamp mark on cylinder block, use it as a correct reference.
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:
- There is no piston grade "1".
- Piston is available together with piston pin as an assembly.
- The piston pin (piston pin hole) grade is provided only for the parts installed at the plant. For service parts, no grades can be selected. (Only grade "0" is available.)
How to Select Connecting Rod Bearing
When New Connecting Rod and Crankshaft Are Used
1) Apply connecting rod big end diameter grade stamped on connecting rod side face to the row in the "Connecting Rod Bearing Selection Table".
2) Apply crankshaft pin journal diameter grade stamped on crankshaft front side to the column in the "Connecting Rod Bearing Selection Table".
3) Read the symbol at the cross point of selected row and column in the "Connecting Rod Bearing Selection Table".
4) Apply the symbol obtained to the "Connecting Rod Bearing Grade Table" to select connecting rod bearing.
When Crankshaft and Connecting Rod Are Reused
5) Measure the dimensions of the connecting rod big end diameter and crankshaft pin journal diameter individually. Refer to [Engine Unit: Inspection After Disassembly] Inspection After Disassembly and [Engine Unit: Inspection After Disassembly] Inspection After Disassembly.
6) Apply the measured dimension to the "Connecting Rod Bearing Selection Table".
7) Read the symbol at the cross point of selected row and column in the "Connecting Rod Bearing Selection Table".
8) Apply the symbol obtained to the "Connecting Rod Bearing Grade Table" to select connecting rod bearing.
Connecting Rod Bearing Selection Table
Connecting Rod Bearing Grade Table
Unit: mm (in)
*: Always check with the Parts Department for the latest parts information.
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 the 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 main bearing housing grade on rear-left side of cylinder block.
- If there is a corrected stamp mark on cylinder block, use it as a correct reference.
2) Apply main journal diameter grade stamped on crankshaft front side to column in the "Main Bearing Selection Table".
3) Read the symbol at the cross point of selected row and column in the "Main Bearing Selection Table".
CAUTION:
There are two main bearing selection tables. One is for odd-numbered journals (No. 1, 3 and 5) and the other is for even-numbered journals (No. 2 and 4). Make certain to use the appropriate table. This is due to differences in the specified clearances.
4) Apply the symbol obtained to the "Main Bearing Grade Table" to select main bearing.
NOTE:
Service part is available as a set of both upper and lower.
When Cylinder Block and Crankshaft Are Reused
5) Measure the dimensions of the cylinder block main bearing housing inner diameter and crankshaft main journal diameter individually. Refer to [Engine Unit: Inspection After Disassembly] Inspection After Disassembly and [Engine Unit: Inspection After Disassembly] Inspection After Disassembly.
6) Apply the measured dimension to the "Main Bearing Selection Table".
7) Read the symbol at the cross point of selected row and column in the "Main Bearing Selection Table".
CAUTION:
There are two main bearing selection tables. One is for odd-numbered journals (No. 1, 3 and 5) and the other is for even-numbered journals (No. 2 and 4). Make certain to use the appropriate table. This is due to differences in the specified clearances.
8) Apply the symbol obtained to the "Main Bearing Grade Table" to select main bearing.
NOTE:
Service part is available as a set of both upper and lower.
Main Bearing Selection Table (No. 1, 3 and 5 journals)
Main Bearing Selection Table (No. 2 and 4 journals)
Main Bearing Grade Table (All Journals)
Unit: mm (in)
*: Always check with the Parts Department for the latest parts information.
Undersize Bearing Usage Guide
- When the specified main bearing oil clearance is not obtained with standard size main bearings, use undersize (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 fillet R [1.5 - 1.7 mm (0.059 - 0.067 in)].
Bearing undersize table
Unit: mm (in)
