MG MG6 Series 2011 Service Manual page 191

Engine Mechanical-1.8 VCT
15. Remove valve spring, cap and valve.
16. Remove valve stem seal usingT10006.
Refit
1. Remove carbon from valve guide, valve, valve seat
insert and combustion area. Remove all loose particles
of carbon on completion.
2. Check existing valve stem diameter. Check valve guide
clearance using new valve (Refer to specification).
3. Check condition of valve seat and valve, if to be reused.
4. Re-cut valve seat and use pilot and the following cutters:
a. 15° MS76-120 - To cut first angle
b. 45° MS76-122 - To make final cut and remove any
burrs
Version 2.0
c. 60° MS76-111- To narrow valve seats and obtain seat
widths
5. Cut valve face angle and valve seat to the following:
• Valve seat:
Angle = 45°
Width A:
Inlet = 1.2 mm;
Exhaust = 1.6 mm
• Valve face angle B:
Inlet = 45°
Exhaust = 45°
6. Lap valve to seat using fine grinding paste.
7. Apply Prussian Blue to valve seat, insert valve and press
into position without rotating. Remove and check for
even and central seating. Seating position shown by
blue should be in centre of valve face.
8. Lap and re-check valve seating.
9. Check valve stem fitted height (Refer to specification).
10. If it still over limit renew cylinder head and camshaft
carrier assembly.
Intake and Exhaust Valve Seat Repair Dimensions
Intake
A=15°
B=45°
C=60°
D=0.4 mm radius
E=29.560 to 29.573mm
F=1.2mm
G=26.43mm
H=29.475 to 29.500mm
J=5.95 to 6.00mm
K=6.16 to 6.32mm
Engine
Exhaust
A=15°
B=45°
C=60°
D=0.4 mm radius
E=25.960 to 25.973mm
F=1.6mm
G=22.83mm
H=25.913 to 25.888mm
J=5.45 to 5.80mm
K=5.70 to 5.86mm
175