47257 Mercury GASKET, POWERHEAD TO EXHAUST EXTENSION PLATE

Illustration 1 g00526366
(1) Spring Length under test force ... 43.0 mm (1.69 inch) Test force ... 177 to 196 N (39.8 to 44.1 lb) Free length after test ... 48.85 mm (1.923 inch) Maximum bend in spring ... 1.5 degrees (2) Valve stem seal (3) Height to top of valve guide ... 14.00 0.10 mm (0.551 0.004 inch) (4) Diameter of valve stem Exhaust valve stem ... 7.920 to 7.940 mm (0.3118 to 0.3126 inch) Minimum allowable diameter for exhaust valve stem ... 7.85 mm (0.309 inch) Clearance for exhaust valve stem in valve guide ... 0.070 to 0.105 mm (0.0028 to 0.0041 inch) Maximum allowable clearance for guide for exhaust valve ... 0.20 mm (0.008 inch) Inlet valve stem ... 7.940 to 7.955 mm (0.3126 to 0.3132 inch) Minimum allowable diameter for inlet valve stem ... 7.90 mm (0.311 inch) Clearance for inlet valve stem in valve guide ... 0.055 to 0.085 mm (0.0022 to 0.0033 inch) Maximum allowable clearance for guide for inlet valve ... 0.150 mm (0.0059 inch) (5) Outside diameter of valve guide Outside diameter of guide for exhaust valve ... 12.033 to 12.044 mm (0.4737 to 0.4742 inch) Inside diameter of guide for new exhaust valve ... 8.020 to 8.035 mm (0.3157 to 0.3163 inch) Outside diameter of guide for inlet valve ... 12.033 to 12.044 mm (0.4737 to 0.4742 inch) Inside diameter of guide for new inlet valve ... 8.020 to 8.035 mm (0.3157 to 0.3163 inch) Inside diameter of new valve guide for exhaust valves and inlet valves ... 7.600 0.100 mm (0.2992 0.0039 inch) Enlarge the inside diameter for newly installed valve guides to the following dimensions. ... 8.000 to 8.015 mm (0.3150 to 0.3156 inch) (6) Thickness of lip Valve lip thickness for inlet and exhaust valves ... 2.13 mm (0.084 inch) Minimum allowable valve lip thickness for inlet and exhaust valves ... 1.83 mm (0.072 inch) (7) Angle of valve face ... 30 degrees
Illustration 2 g00526884
(8) Depth of bore in head for valve seat insert ... 8.0 0.1 mm (0.315 0.004 inch) (9) Chamfer of the inlet valve Angle of chamfer of the inlet valve ... 45 degrees The depth of the chamfer of the inlet valve from the face of the cylinder head ... 2.0 0.1 mm (0.08 0.004 inch) (10) Chamfer of exhaust valve Angle of chamfer of the inlet valve ... 45 degrees The depth of the chamfer of the exhaust valve from the face of the cylinder head ... 2.0 0.1 mm (0.08 0.004 inch) (11) Valve seat bore for inlet valve ... 46.000 to 46.025 mm (1.8110 to 1.8120 inch) (12) Valve seat bore for exhaust valve ... 37.000 to 37.025 mm (1.4567 to 1.4577 inch)
Illustration 3 g00527479
(13) Dimension of the valve seat Width of valve seat ... 1.40 0.14 mm (0.055 0.006 inch) The maximum permissible width of the valve seat ... 1.80 mm (0.071 inch) (14) Valve seat angle ... 30 degrees (15) Dimension from top of closed valve to face of head Exhaust valve ... 0.50 0.20 mm (0.020 0.008 inch) Inlet valve ... 0.4 0.2 mm (0.016 0.008 inch) The maximum permissible depth before replacement of the valve seat ... 1.0 mm (0.04 inch)
Illustration 4 g00527490
(16) Pushrod Use a dial indicator in order to check all pushrods for runout. Replace the pushrod if the runout exceeds the following value. ... 0.30 mm (0.012 inch)