893692A01 Mercury COVER ASSEMBLY, Exhaust

Illustration 1 g03331363
Table 1
Specifications for the Valve Spring
Callout Quantity Type of Engine Specification Description
1 - Naturally aspirated engines Length of the valve springs under test force 33.5 mm (1.318 inch)
Test force of the valve springs 254 N (57.1 lb)
1 - Turbocharged engines Length of the valve springs under test force 34.5 mm (1.358 inch)
Test force of the valve springs 229 N (51.4 lb)
2 - - Valve spring recess
Table 2
Specifications for the Valve Guides
Note When new valve guides are installed, new valves and new valve seat inserts must be installed. The valve guides and the valve seat inserts are supplied as partially finished parts. The unfinished valve guides and unfinished valve seat inserts are installed in the cylinder head. Then, the guides and inserts are cut and reamed in one operation with special tooling. This procedure ensures the concentricity of the valve seat to the valve guide in order to create a seal that is tight. Refer to the Disassembly and Assembly Manual for removal and installation procedures.
Callout Quantity Type of Engine Specification Description
3 - - Inside diameter of valve guide
9.000 to 9.022 mm (0.3543 to 0.3552 inch)
3 - - Outside diameter of the exhaust valve guide
13.034 to 13.047 mm (0.5131 to 0.5137 inch)
3 - - Outside diameter of the inlet valve guide
13.034 to 13.047 mm (0.5131 to 0.5137 inch)
3 - - Interference fit of valve guide in cylinder head
0.007 to 0.047 mm (0.0003 to 0.0019 inch)
3 - - Length of Valve guide
51.00 to 51.50 mm (2.018 to 2.027 inch)
3 - - Projection of the valve guide above the valve spring recess (2)
12.35 to 12.65 mm (0.486 to 0.498 inch)
Table 3
Specifications for the Exhaust Valve
Callout Quantity Type of Engine Specification Description
4 - - Diameter of the exhaust valve stem
8.938 to 8.960 mm (0.3519 to 0.3528 inch)
4 - - Clearance of valve in valve guide
0.040 to 0.840 mm (0.0016 to 0.033 inch)
4 - - Overall length of the exhaust valve
128.92 to 129.37 mm (5.075 to 5.093 inch)
The face of the exhaust valve is recessed below the cylinder head by the following amount.
4 - Naturally aspirated engines 0.53 to 0.81 mm (0.021 to 0.032 inch)
4 - - Service limit
1.06 mm (0.042 inch)
4 - Turbocharged engines 1.53 to 1.81 mm (0.060 to 0.071 inch)
4 - - Service limit
2.06 mm (0.0811 inch)
Table 4
Specifications for the Inlet valve
Callout Quantity Type of Engine Specification Description
5 - - Diameter of the inlet valve stem
8.953 to 8.975 mm (0.3525 to 0.3533 inch)
5 - - Clearance of valve in valve guide
0.025 to 0.069 mm (0.001 to 0.0027 inch)
5 - - Overall length of the inlet valve
128.92 to 129.37 mm (5.075 to 5.093 inch)
The face of the inlet valve is recessed below the cylinder head by the following amount.
5 - Naturally aspirated engines 0.58 to 0.84 mm (0.023 to 0.033 inch)
5 - - Service limit
1.09 mm (0.043 inch)
5 - Turbocharged engines 1.58 to 1.84 mm (0.062 to 0.072 inch)
5 - - Service limit
2.09 mm (0.0823 inch)
Table 5
Specifications for the Exhaust Valve Face Angle (from the Vertical Axis)
Callout Quantity Type of Engine Specification Description
A - - Valve face angle
30 degrees
A - - Valve seat angle
30 degrees
Table 6
Specifications for the Diameter of the Exhaust Valve Head
Callout Quantity Type of Engine Specification Description
B - - 41.51 to 41.75