Description
Correspondence | Selectable Component | Selection criterion | Selection method |
Between cylinder block and crankshaft | main bearing | Main bearing class (bearing thickness) | Determined by matching the class of the main bearing housing in the cylinder block (body inner diameter) and class of the crankshaft main journal (neck outside diameter) |
Between crankshaft and connecting rod | Connecting rod bearing | Connecting rod bearing class (bearing thickness) | The selection of the connecting rod bearing is determined by a combination of repair classes of the inner diameter of the large head of the connecting rod and the outer diameter of the connecting rod journal. |
- The class marking embossed on each part represents the dimensional class measured on the new part. This class does not apply to reusable parts.
- Perform precise geometric measurements on reused or repaired parts. Determine the class by comparing the measurement results with the values presented in the individual component selection tables.
- For more details on how to measure each part, recycling rates and how to select components on site, see the text.
Connecting rod bearing selection procedure
When new connecting rod and crankshaft are used
1 Find the diameter class of the big end of the connecting rod (WITH), embossed on the side of the connecting rod, in a horizontal line «Conrod bearing selection tables».
A. Main journal diameter class
B. Crankpin Diameter Class
D. Transfer mark
2. Find the crankpin diameter class (IN), embossed on the front of the crankshaft, in a vertical column «Conrod bearing selection tables».
A. Oil hole
B. Cylinder number
3. Read the character at the intersection of the horizontal line and vertical column in «Conrod bearing selection table».
4. Select the connecting rod bearing by matching the resulting symbol with the values in «Connecting rod bearing grade table».
When the old crankshaft and connecting rod are reused
1. Measure the inner diameter of the big end of the connecting rod and the outer diameter of the connecting rod journal. See relevant sections.
2. Find the resulting value in «Conrod bearing selection table».
3. Read the character at the intersection of the horizontal line and vertical column in «Conrod bearing selection table».
4. Select the connecting rod bearing by matching the resulting symbol with the values in «Connecting rod bearing class table».
Conrod bearing selection table
Connecting rod bearing grade table
Unit: mm
Guidelines for the use of undersized bearings
If the specified oil clearance cannot be achieved with standard size connecting rod bearings, use undersized bearings.
When using an undersized bearing, measure the inner diameter of the connecting rod bearing on the installed bearing and regrind the crankpin so that the oil clearance is correct.
Attention: When regrinding the connecting rod journals for bearings of a reduced repair size, keep the rounded corners R (A) (0.8-1.2mm).
Table of reduced oversize bearings
Unit: mm
Size | Thickness |
Repair size reduced by 0.25 | 1,623-1,631 |
The procedure for selecting main bearings
When a new cylinder block and crankshaft are used
1. Horizontal lines in «Selection table for main bearings» correspond to the class of the main bearing housing stamped on the left side of the cylinder block.
A. Basic marking
If a correction mark is embossed on the cylinder block (IN), use it as standard.
2. Find the journal diameter class (A), embossed on the front of the crankshaft, in a vertical column «Selection tables for main bearings».
A. Main journal diameter class (№№1-5 from the left in order)
B. Crankpin Diameter Class (№№1-4 from the left in order)
3. Read the character at the intersection of the horizontal line and vertical column in «Selection table for main bearings».
4. Select the main bearing by matching the resulting symbol with the values in «Main bearing class table».
Selection table for main bearings
Main bearing class table
Intent unit: mm
Guidelines for the use of undersized bearings
If the specified oil clearance cannot be achieved with standard size main bearings, use undersized bearings.
When using an undersized bearing, measure the inside diameter of the main bearing with the bearing installed and regrind the main journal so that the oil clearance is correct.
Attention: When regrinding the main journals for undersized bearings, keep the rounded corners R (A) (0.8-1.2mm).
Table of reduced oversize bearings
Unit: mm
Size | Thickness |
Repair size reduced by 0.25 | 2,126-1,134 |