- Engine:
- 3600 Diesel
Oversized valve seat inserts are available for use in 3600 series diesel engines. The new inserts provide increased serviceability of the cylinder head. Caterpillar Reman cylinder heads may contain these valve seat inserts. See Table 1 and Table 2 for the available configurations of valve seat inserts.
| Specifications Of Non-Water Cooled Valve Seat Inserts | |||||
| Part Number | Valve Seat Angle (degrees) | Oversized Dimension (mm) | Usage | Installed Concentricity (TIR) | Replaced Part |
| 183-5075 | 30.75 | 1.00 | Intake | 0.07 mm | 160-5769 |
| 183-5076 | 30.75 | 0.50 | Intake | 0.07 mm | 160-5769 |
| 183-5077 | 30.75 | 1.00 | Exhaust | 0.07 mm | 160-5770 |
| 183-5078 | 30.75 | 0.50 | Exhaust | 0.07 mm | 160-5770 |
| 203-9568 | 20.5 | 1.00 | Intake | 0.07 mm | 171-3992 |
| 203-9566 | 20.5 | 0.50 | Intake | 0.07 mm | 171-3992 |
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| Illustration 1 | g00884755 |
Non-water cooled valve seat insert | |
| Specifications Of Water Cooled Valve Seat Inserts | |||||
| Part Number | Valve Seat Angle (degrees) | Oversized Dimension (mm) | Usage | Installed Concentricity (TIR) | Replaced Part |
| 183-5079 | 30.75 | 1.00 | Exhaust | 0.08 mm | 160-5771 |
| 183-5080 | 30.75 | 0.50 | Exhaust | 0.80 mm | 160-5771 |
| 183-5081 | 45 | 1.00 | Exhaust | 0.08 mm | 173-8386 |
| 183-5082 | 45 | 0.50 | Exhaust | 0.80 mm | 173-8386 |
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| Illustration 2 | g00884756 |
Water cooled valve seat insert | |
Oversized machining of the bore for the valve seat insert in the cylinder head is required. Since the valve guides act as pilots for the tool that machines the bores,Caterpillar recommends installing new valve guides in the head before machining the bore for the insert. The bores for the valve seat inserts need to be machined to the dimensions that are listed in Table 3 and Table 4.
| Machining Specifications For Non-Water Cooled Inserts | ||
| Part Number | Dimension A (mm) | TIR A (mm) |
| 183-5075 | 98.00 ± 0.025 | 0.04 |
| 183-5076 | 97.50 ± 0.025 | 0.04 |
| 183-5077 | 98.00 ± 0.025 | 0.04 |
| 183-5078 | 97.50 ± 0.025 | 0.04 |
| 203-9566 | 97.50 ± 0.025 | 0.04 |
| 203-9568 | 98.00 ± 0.025 | 0.04 |
Note: TIR A is the total indicator reading of the bore (A) for the insert, which is measured off the valve guides.
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| Illustration 3 | g00884757 |
| Machining Specifications For Water Cooled Inserts | ||||
| Part Number | Dimension B (mm) | TIR B (mm) | Dimension C (mm) | TIR C (mm) |
| 183-5079 | 94.50 ± 0.025 | 0.03 | 109.50 ± 0.025 | 0.04 |
| 183-5080 | 94.00 ± 0.025 | 0.03 | 109.00 ± 0.025 | 0.04 |
| 183-5081 | 94.50 ± 0.025 | 0.03 | 109.50 ± 0.025 | 0.04 |
| 183-5082 | 94.00 ± 0.025 | 0.03 | 109.00 ± 0.025 | 0.04 |
Note: TIR B is the total indicator reading of the bore (B) for the insert. To measure TIR B, first measure TIR C and record TIR C. Then measure TIR B and record TIR B without moving the valve guide pilot. The difference of TIR C to TIR B at any given location must be less than 0.03 mm (0.0012 inch).
Note: TIR C is the total indicator reading of bore (C) for the insert, which is measured off the valve guide.
 | |
| Illustration 4 | g00884759 |
The valve seat inserts have premachined valve seat faces. If the inserts are installed correctly, and if the bore in the cylinder head has been machined properly, the inserts do not require grinding, machining, or lapping after installation.
The interface between the valve and the valve seat insert must always be checked after a cylinder head has been rebuilt. The valve should contact the valve seat insert around the entire circumference of the valve face. The valve should contact the valve seat insert at the outer diameter of the valve face. The interface can be verified with 9U-6076 Prussian Blue or with the FT-1741 Vacuum Test Group. If the valve does not seal properly with the valve seat insert, the valve can be damaged during operation. A poor seal can result if the insert bore or the sealing face of the valve seat insert is not concentric with the valve guide, or if the valve is bent.