309-01136-0 Nissan NIPPLE, M8-6.8

(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)Intake 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)Intake valve ... 44.98 0.13 mm (1.771 .005 in)(5) Angle of intake valve face ... 29 1/4 1/4 degreesAngle 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 intake valve ... 46.025 0.013 mm (1.8120 .0005 in) Bore in head for valve seat insert for intake valve ... 45.949 0.025 mm (1.8090 .0010 in)(8) Angle of face of intake valve seat insert ... 30 1/4 1/2 degreesAngle 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 intake and exhaust ... 1.07 mm (.042 in)Minimum permissible dimension for intake 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)Intake seat ... 44.04 0.13 mm (1.734 .005 in)(11) "Use again" thickness of valve lip: Intake valves ... 2.51 mm (.099 in)Exhaust valves ... 2.03 mm (.080 in) Procedure to Check Intake Valve Lash Timing1. Check the No. 1 intake valve clearance with the engine stopped. The valve clearance must be 0.30 to 0.46 mm (.012 to .018 in). If the valve clearance is not in this range, adjust the clearance 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 intake valve movement.4. Rotate the crankshaft in the direction of normal engine rotation. Stop when the intake 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.