Valve, Valve Guide Inspection
VALVE, VALVE GUIDE INSPECTION
1. Measure the valve head margin thickness using a vernier caliper.
- If it is less than the standard specification, replace the valve.
Standard valve head margin thickness
IN: 1.75-1.95 mm {0.0689-0.0767 in}
EX: 1.95-2.15 mm {0.0768-0.0846 in}
2. Measure the length of the each valve using a vernier caliper.
- If it is less than the minimum specification, replace the valve.
Standard valve length
IN: 106.55-107.15 mm {4.1949-4.2185 in}
EX: 116.55-117.15 mm {4.5886-4.6122 in}
Minimum valve length
IN: 106.33 mm {4.1862 in}
EX: 116.33 mm {4.5799 in}
3. Measure the valve stem diameter of each valve using the micrometer. Measurement positions total six and are in the X and Y directions, at three points (A, B, and C) as shown in the figure.
- If it is less than the minimum specification, replace the valve.
Standard valve stem diameter
IN: 5.470-5.485 mm {0.2154-0.2159 in}
EX: 5.465-5.480 mm {0.2152-0.2157 in}
Minimum valve stem diameter
IN: 5.424 mm {0.2135 in}
EX: 5.419 mm {0.2133 in}
4. Measure the inner diameter of each valve guide using the caliper gauge. Measurement positions total six and are in the X and Y directions, at three points (A, B, and C) as shown in the figure.
- If it is not within the specification, replace the valve guide.
Standard valve guide inner diameter
IN: 5.510-5.530 mm {0.2170-0.2177 in}
EX: 5.510-5.530 mm {0.2170-0.2177 in}
5. Calculate the clearance between the valve stem and the valve guide by subtracting the inner diameter of the valve guide from the outer diameter of the corresponding valve stem.
- If it exceeds the maximum specification, replace the valve or valve guide.
Standard clearance between valve stem and guide
IN: 0.025-0.060 mm {0.0010-0.0023 in}
EX: 0.030-0.065 mm {0.0012-0.0025 in}
Maximum clearance between valve stem and guide 0.10 mm {0.0039 in}
6. Measure the projection height (dimension A) of each valve guide using the vernier caliper.
- If it is not within the specification, replace the valve guide.
Standard valve guide projection height
IN: 16.4-17.0 mm {0.646-0.669 in}
EX: 16.4-17.0 mm {0.646-0.669 in}