How to Select Piston And Bearing

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 a piston pin and a 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 procedure.

HOW TO SELECT PISTON

Piston Selective Fitting When New Cylinder Block is Used:





- Check the cylinder bore grade on the bottom face of the cylinder block, and select the piston of the same grade.






When Cylinder Block is Reused
1. Measure cylinder block bore diameter.
2. Determine the bore grade by comparing the measurement with the values under the "Cylinder bore diameter" of the piston selection table.

Piston Selection Table






NOTE:
- The piston is available together with piston pin as an assembly.
- The piston pin (piston pin bore) grade is provided only for the parts installed at the plant. For service parts, no grades can be selected (only 0 grade is available).

HOW TO SELECT CONNECTING ROD BEARING

When New Connecting Rod and Crankshaft are Used





1. Apply the big end inside diameter grade stamped on the connecting rod side face to the row in the "Connecting Rod Bearing
Selection Table".





2. Apply the pin diameter grade stamped on the crankshaft front side to the column in the "Connecting Rod Bearing Selection
Table".
3. Read the symbol at the cross point of the 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.

When Crankshaft and Connecting Rod are Reused
1. Measure dimensions of the big end inside diameter of the connecting rod and diameter of the crankshaft pin individually.
2. Apply the measured dimension to the "Connecting Rod Bearing Selection Table".
3. The following steps are the same as in "When New Connecting Rod and Crankshaft are Used".

Connecting Rod Bearing Selection Table






Connecting Rod Bearing Grade Table.






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





Bearing undersize table






CAUTION:
In grinding the crankshaft pin to use undersize bearings, keep the fillet R (All crankshaft pins).

Fillet R : 1.5 - 1.7 mm (0.059 - 0.067 in)


HOW TO SELECT MAIN BEARING

When New Cylinder Block and Crankshaft are Used





1. Apply the main bearing housing grade on the bottom face of the cylinder block to the row in "Main Bearings Selection Table".





2. Apply the journal diameter grade on the crankshaft front to the column in "Main Bearings Selection Table".
3. Read the symbol at the cross point of the selected row and column in the "Main Bearings Selection Table".

CAUTION:
- Initial clearance for No. 1, 5 journal and No. 2, 3, 4 journal is different. Use two different selection lists for each part.
- No. 1, 5 journal and No. 2, 3, 4 journal have the same signs but different measures. Do not confuse them.
4. Apply the symbol to the "Main Bearings Grade Table" to select.

NOTE:
- Grade list applies to all journals.
- Service parts are available as a set of both upper and lower.

When Cylinder Block and Crankshaft are Reused
1. Measure the inside diameter of the cylinder block main bearings housing and the outside diameter of the crankshaft journal.
2. Apply measurement in above step 1 to "Main Bearings Selection Table".
3. The following steps are same as in "When New Cylinder Block and Crankshaft are Used".

Main Bearings Selection Table (No. 1 and No. 5 journal)






Main Bearings Selection Table (No. 2, 3 and 4 journal)






Main Bearings Grade Table (All Journals)






Use Undersize Bearing Usage Guide
- Use undersize (US) bearing when the oil clearance with standard size main bearing is not within specification.
- When using undersize (US) bearing, measure the inside diameter of the bearing installed and grind the journal until the oil clearance falls within specification.





Bearing undersize table






CAUTION:
Do not damage fillet R when grinding crankshaft journal in order to use undersized bearing (All journals).

Fillet R : 1.5 - 1.7 mm (0.059 - 0.067 in)