Express 3/4 Ton Van V8-5.7L VIN R (1998)
Valve: Specifications
Valve Face Angle .............................................................................................................................................................................................. 45 degrees
Valve Head Edge Margin ........................................................................................................................ 0.79 mm (Minimum) (10.031 inch (Minimum))
Valve Lash ...................................................................................... Rotate the Valve Rocker Arm Nut Clockwise 360 degrees (1 Turn) from Zero Lash
Valve Lifter ............................................................................................................................................................................................. Hydraulic Roller
Valve Rocker ............................................................................................................................................................................................ Arm Ratio 1.5:1
Valve Seat Angle .............................................................................................................................................................................................. 46 degrees
Valve Seat Runout ................................................................................................................................... 0.05 mm (Maximum) (0.002 inch (Maximum))
Valve Seat Width (Exhaust-Heavy Duty) .................................................................................................................. 1.50 - 2.56 mm (0.059 - 0.101 inch)
Valve Seat Width (Exhaust-Light Duty) ................................................................................................................... 1.65 - 2.49 mm (0.065 - 0.098 inch)
Valve Seat Width (Intake) ......................................................................................................................................... 1.02 - 1.65 mm (0.040 - 0.065 inch)
Valve Spring Free Length .................................................................................................................................................................. 51.3 mm (2.02 inch)
Valve Spring Installed Height ................................................................................................................... (Exhaust) 42.92 - 43.43 mm (1.67 - 1.70 inch)
Valve Spring Installed Height ...................................................................................................................... (Intake) 42.92 - 43.43 mm (1.67 - 1.70 inch)
Valve Spring Pressure (Closed) ......................................................................................................................... 338 - 374 N at 43.2 (76 - 84 lbs. at 1.70)
Valve Spring Pressure (Open) ....................................................................................................................... 832 - 903 N at 32.3 (187 - 203 lbs. at 1.27)
Valve Stem Clearance (Exhaust-Production) .................................................................................................... 0.025 - 0.069 mm (0.0010 - 0.0027 inch)
Valve Stem Clearance (Intake-Production) ....................................................................................................... 0.025 - 0.069 mm (0.0010 - 0.0027 inch)
Valve Stem Clearance (Exhaust-Service) ......................................................................................................... 0.025 - 0.094 mm (0.00 10 - 0.0037 inch)
Valve Stem Clearance (Intake-Service) ............................................................................................................ 0.025 - 0.094 mm (0.0010 - 0.0037 inch)
Valve Stem Diameter ........................................................................................................................................ 8.661 - 8.679 mm (0.3410 - 0.3416 inch)
Valve Stem Oil Seal Installed Height (Measured from the Top of Large Valve Guide Bevel to the Bottom of the Valve Stem Oil Seal) ................ 1 - 2
mm (0.03937 - 0.07874 inch)
