Cylinder Head

Cylinder Head





Unit: mm (inch)
Head surface distortion
Standard Less than 0.03 (0.0012)
Limit 0.1 (0.004)

VALVE





Unit: mm (inch)
Valve head diameter "D"
Intake 37.0 - 37.3 (1.4567 - 1.4685)
Exhaust 31.2 - 31.5 (1.228 - 1.240)
Valve length "L"
Intake 96.12 - 96.62 (3.7842 - 3.8039)
Exhaust 93.65 - 94.15 (3.6870 - 3.7067)
Valve stem diameter "d"
Intake 5.965 - 5.980 (0.2348 - 0.2354)
Exhaust 5.955 - 5.970 (0.2344 - 0.2350)
Valve seat angle "a"
Intake 45 degrees 15 ft. - 45 degrees 45 ft.
Exhaust 45 degrees 15 ft. - 45 degrees 45 ft.
Valve margin "T"
Intake 1.15 - 1.45 (0.0453 - 0.0571)
Exhaust 1.45 - 1.75 (0.0571 - 0.0689)
Valve margin "T" limit More than 0.5 (0.020)
Valve stem end surface grinding limit Less than 0.2 (0.008)

VALVE CLEARANCE
Unit: mm (inch)
Intake
Cold 0.26 - 0.34 (0.010 - 0.013)
Hot* (reference data) 0.304 - 0.416 (0.012 - 0.016)
Exhaust
Cold 0.29 - 0.37 (0.011 - 0.015)
Hot* (reference data) 0.308 - 0.432 (0.012 - 0.017)
*: Approximately 80 degrees C (176 degrees F)

VALVE SPRING
Free height mm (inch) 45.62 (1.7961)
Pressure N (kg, lbs.) at height mm (inch)
Standard 196 (20.0, 44.1) at 37.0 (1.457)
Limit 433 (44.2, 97.3) at 27.8 (1.094)
Out-of-square mm (inch) Less than 2.0 (0.079)

VALVE LIFTER
Unit: mm (inch)
Valve lifter outer diameter 133.977 - 33.987 (1.3377 - 1.3381)
Lifter guide inner diameter 34.000 - 34.016 (1.3386 - 1.3392)
Clearance between lifter and lifter guide 0.013 - 0.039 (0.0005 - 0.0015)

Identification mark Thickness mm (inch)





788C 7.88 (0.3102)
790C 7.90 (0.3110)
792C 7.92 (0.3118)
794C 7.94 (0.3126)
796C 7.96 (0.3134)
798C 7.98 (0.3142)
800C 8.00 (0.3150)
802C 8.02 (0.3157)
804C 8.04 (0.3165)
806C 8.06 (0.3173)
808C 8.08 (0.3181)
810C 8.10 (0.3189)
812C 8.12 (0.3197)
814C 8.14 (0.3205)
816C 8.16 (0.3213)
818C 8.18 (0.3220)
820C 8.20 (0.3228)
822C 8.22 (0.3236)
824C 8.24 (0.3244)
826C 8.26 (0.3252)
828C 8.28 (0.3260)
830C 8.30 (0.3268)
832C 8.32 (0.3276)
834C 8.34 (0.3283)
836C 8.36 (0.3291)

VALVE GUIDE





Unit: mm (inch)
Outer diameter
Standard 10.023 - 10.034 (0.3946 - 0.3950)
Service 10.223 - 10.234 (0.4025 - 0.4029)
Inner diameter (Finished size) 6.000 - 6.018 (0.2362 - 0.2369)
Cylinder head valve guide hole diameter
Standard 9.975 - 9.996 (0.3927 - 0.3935)
Outer diameter 10.175 - 10.196 (0.4006 - 0.4014)
Interference fit of valve guide 0.027 - 0.059 (0.0011 - 0.0023)
Stem to guide clearance
Intake
Standard 0.020 - 0.053 (0.0008 - 0.0021)
Max. tolerance 0.08 (0.0031)
Exhaust
Standard 0.030 - 0.063 (0.0012 - 0.0025)
Max. tolerance 0.09 (0.0035)
Valve deflection limit
Intake
Max. tolerance 0.24 (0.0094)
Exhaust
Max. tolerance 0.28 (0.0110)
Projection length "L" 12.6 - 12.8 (0.496 - 0.504)

Valve Seat





Unit: mm (inch)
Cylinder head seat recess diameter (D)
Intake
Standard 38.000 - 38.016 (1.4961 - 1.4967)
Service 38.500 - 38.516 (1.5157 - 1.5164)
Exhaust
Standard 32.200 - 32.216 (1.2677 - 1.2683)
Service 32.700 - 32.716 (1.2874 - 1.2880)
Valve seat interference fit
Intake 0.081 - 0.113 (0.0032 - 0.0044)
Exhaust 0.064 - 0.096 (0.0025 - 0.0038)
Valve seat outer diameter (d)
Intake
Standard 38.097 - 38.113 (1.4999 - 1.5005)
Service 38.597 - 38.613 (1.5196 - 1.5202)
Exhaust
Standard 32.280 - 32.296 (1.2709 - 1.2715)
Service 32.780 - 32.796 (1.2905 - 1.2912)
Height (h)
Intake
Standard 5.9 - 6.0 (0.232 - 0.236)
Service 5.05 - 5.15 (0.1988 - 0.2028)
Exhaust
Standard 5.9 - 6.0 (0.232 - 0.236)
Service 4.95 - 5.05 (0.1949 - 0.1988)
Depth (H) 5.9 - 6.1 (0.232 - 0.240)
Depth (L)
Intake 41.07 - 41.67 (1.6169 - 1.6405)
Exhaust 41.00 - 41.60 (1.6142 - 1.6378)

Camshaft and Camshaft Bearing
Unit: mm (inch)
Camshaft journal to bearing clearance
Standard
No. 1 0.045 - 0.086 (0.0018 - 0.0034)
No. 2, 3, 4 0.035 - 0.076 (0.0014 - 0.0030)
Limit 0.15 (0.0059)
Inner diameter of camshaft bearing
Standard
No. 1 26.000 - 26.021 (1.0236 - 1.0244)
No. 2, 3, 4 23.500 - 23.521 (0.9252 - 0.9260)
Outer diameter of camshaft journal
Standard
No. 1 25.935 - 25.955 (1.0211 - 1.0218)
No. 2, 3, 4 23.445 - 23.465 (0.9230 - 0.9238)
Camshaft runout [TIR*]
Standard Less than 0.02 (0.0008)
Limit 0.05 (0.0020)
Camshaft sprocket runout [TIR*]
Standard Less than 0.15 (0.0059)
Camshaft end play
Standard 0.115 - 0.188 (0.0045 - 0.0074)
Limit 0.24 (0.0094)
* Total indicator reading





Cam height "A"
Intake and Exhaust 44.865 - 45.055 (1.7663 - 1.7738)
Wear limit of cam height 0.2 (0.008)
Valve timing





Intake valve timing control - OFF
a 240°
b 238°
c -6°
d 64°
e 8°
f 52°