Service Specifications

CYLINDER HEAD
Valve Seat Type Powdered Metal Inserts
Valve Seat Run-Out (Maximum) 0.760 mm (0.003 in.)
Intake Valve Seat Angle 45 - 45 1/2°
Seat Width (Finished) 1.75 - 2.25 mm
(0.069 - 0.088 in.)
Exhaust Valve Seat Angle 45 - 45 1/2°
Seat Width (Finished) 1.50 - 2.00 mm
(0.057 - 0.078 in.)
Cylinder Head Gasket (Thickness Compressed) 1.78 mm (0.070 in.)

VALVE GUIDES
Type Powdered Metal Inserts
Guide Bore Diameter 7.795 - 8.000 mm
(0.313 - 0.3149 in.)

VALVES (INTAKE)
Head Diameter 45.5 mm (1.79 in.)
Length Overall (New) 125.385 - 126.025 mm
(4.936 - 4.961 in.)
Stem Diameter (Standard) 7.935 - 7.953 mm
(0.312 - 0.313 in.)
Stem to Guide Clearance 0.025 - 0.095 mm
(0.001 - 0.003 in.)
Maximum Allowable (By Rocking Method) 0.247 mm (0.010 in.)
Face Angle 44 1/2°
Valve Margin 0.794 mm (0.031 in.)
Valves for Service Standard
0.015 mm (0.005 in.)
0.40 mm (0.015 in.)
0.80 mm (0.030 in.)
Lift (Zero Lash) 10.16 mm (0.400 in.)
Minimum Valve Length After Grinding Tip 124.892 mm (4.916 in.)
Valve Tip Height
(From Cylinder Head Surface) 49.541 - 51.271 mm
(1.950 - 2.018 in.)

VALVES (EXHAUST)
Head Diameter 37.5 mm (1.476 in.)
Length Overall (New) 126.095 - 126.645 mm
(4.964 - 4.986 in.)
Stem Diameter (Standard) 7.906 - 7.924 mm
(0.3112 - 0.3119 in.)
Stem to Guide Clearance 0.051 - 0.175 mm
(0.002 - 0.006 in.)
Maximum Allowable by Rocking Method 0.414 mm (0.016 in.)
Face Angle 44 1/2°
Valve Margin 1.191 mm (0.0469 in.)
Valves for Service Standard
0.015 mm (0.005 in.)
0.40 mm (0.015 in.)
0.80 mm (0.030 in.)
Lift (Zero Lash) 10.16 mm (0.400 in.)
Minimum Valve Length After Grinding Tip 125.512 mm (4.941 in.)
Valve Tip Height
(From Cylinder Head Surface) 49.541 - 51.271 mm
(1.950 - 2.018 in.)

VALVE SPRINGS.
Number 12
Free Length (Approx.) 48.5 mm (1.909 in.)
Wire Diameter 4.75 mm (0.187 in.)
Number of Coils 6.8
Load When Compressed
Valve Closed 58 - 63 lbs. @ 1.570 in.
Valve Open 136 - 145 lbs. @ 1.14 in.
Valve Spring Installed Height
Spring Seat to Retainer 39.1 - 40.6 mm
(1 17/32 - 1 19/32 in.)