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1.2L REVOTRON ENGINE
62
E. Cylinder Head Valve Seats :
Valve Seat Specification
(REVOTRON 1.2L)
Dimension
Intake Valve
Exhaust Valve
Valve Seat Diameter
29.1 ± 0.05 mm
24.1 ± 0.05 mm
Maximum Runout of Valve Seat with
Respect to Valve Guide Axis
0.030 mm
0.030 mm
Valve Seat Insert Thickness
5.14 -0.1 mm
4.8 -0.1mm
Valve Seat Insert I.D.
27.6 ± 0.1 mm
21.7 ± 0.1 mm
Valve Seat Bore I.D.(in cylinder head)
Normal : 32.39/32.416
Normal : 27.37/27.400
Valve Seat Insert O.D.
Normal : 32.42
(+0.105/+0.080)
Normal 1 : 32.92
(+0.105/+0.080)
Normal : 27.42
(+0.085/+0.064)
Normal 1 : 27.92
(+0.085/+0.064)
Valve Seat Insert Bore Angle
15
0
from vertical alignment with cylinder head mating surface
1. Check the height of each valve seat insert
with respect to the cylinder head mating
surface. Replace the valve seat if worn
beyond the specified limit.
2. Measure the runout of the valve seat with
respect to the valve guide axis. Maximum
runout is 0.030 mm. Replace or resurface the
valve seat(s) as necessary.
Cylinder Head Vale Seat Resurfacing-:
NOTE
The valve seat must be free from chatter
marks, scratches and other specifications.
1. Lap the valves and valve seats to a smooth
and even finish using lapping paste and a
hand pump grinder or by inserting the valve
into the cylinder head and rotating to achieve
the proper finish.
2. Coat the valve seat with carbon blue
I
Prussian blue dye and insert the appropriate
valve into the cylinder head.
3. Rotate the valve under axial pressure several
times and remove from the cylinder head.
4. Inspect the area of contact created by the
axial rotation of the valve.
The contact pattern should be equal and
unbroken around the circumference of the
seat.
The distance from the narrow diameter of
the valve seat face to the contact line
should be 0.5 mm.