Usage:
(1) 4N5906 Spring for valves (new):
Length under test force ... 54.99 mm (2.165 in)
Test force ... 344 ± 34 N (77 ± 7.6 lb)
Use again minimum load at length under test force ... 291 N (65.4 lb)
Length of spring at valve open position ... 42.93 mm (1.690 in)
Use again minimum load at valve open position ... 817 N (183.6 lb)
Free length after test ... 62.7 mm (2.47 in)
Outside diameter ... 31.75 mm (1.250 in)
Spring must not be bent more than ... 2.18 mm (.086 in)
(2) Height to top of valve guide ... 32.3 ± 0.8 mm (1.27 ± .03 in)
(3) Diameter of valve stem (new) ... 9.441 ± 0.008 mm (.3717 ± .0003 in)
Use again minimum diameter of valve stem:
Exhaust valves ... 9.408 mm (.3704 in)
Inlet valves ... 9.408 mm (.3704 in)
Bore in valve guide with guide installed in the head (new) ... 9.487 ± 0.025 mm (.3735 ± .0010 in)
(4) Diameter of valve head:
Exhaust valve ... 41.81 ± 0.13 mm (1.646 ± .005 in)
Inlet valve ... 44.98 ± 0.13 mm (1.771 ± .005 in)
(5) Angle of inlet valve face ... 29 1/4 ± 1/4 degrees
Angle of exhaust valve face ... 44 1/4 ± 1/4 degrees
(6) Depth of bore in head for valve seat insert (new) ... 13.01 ± 0.38 mm (.512 ± .015 in)
(7) Diameter of valve seat insert for exhaust valve ... 42.850 ± 0.013 mm (1.6870 ± .0005 in)
Bore in head for valve seat insert for exhaust valve ... 42.774 ± 0.025 mm (1.6840 ± .0010 in)
(7) Diameter of valve seat insert for inlet valve ... 46.025 ± 0.013 mm (1.8120 ± .0005 in)
Bore in head for valve seat insert for inlet valve ... 45.949 ± 0.025 mm (1.8090 ± .0010 in)
(8) Angle of face of inlet valve seat insert ... 30 1/4 ± 1/2 degrees
Angle of face of exhaust valve seat insert ... 44 3/4 ± 1/2 degrees
(9) Dimension from top of closed valve to face of head:
Maximum permissible dimension for inlet and exhaust ... 1.07 mm (.042 in)
Minimum permissible dimension for inlet and exhaust ... 0.05 mm (.002 in)
(10) Outside diameter of the face of the valve seat insert:
Exhaust seat ... 40.41 ± 0.13 mm (1.591 ± .005 in)
Inlet seat ... 44.04 ± 0.13 mm (1.734 ± .005 in)
(11) "Use again" thickness of valve lip:
Inlet valves ... 2.51 mm (.099 in)
Exhaust valves ... 2.03 mm (.080 in)
Procedure to Check Inlet Valve Timing
1. Check the No. 1 inlet valve lash with the engine stopped. The valve lash must be 0.30 to 0.46 mm (.012 to .018 in). If the valve lash is not in this range, adjust the lash to 0.38 mm (.015 in).
2. Mark Top Center Position of the crankshaft on the vibration damper or pulley.
3. Use a dial indicator to measure the inlet valve movement.
4. Rotate the crankshaft in the direction of normal engine rotation. Stop when the inlet valve is 1.91 mm (.075 in) off its seat in the opening sequence. At this point the crankshaft must be 3 ± 2 degrees After Top Center.