Toyota Celica Supra 1986 Service And Repair Manual page 49

ENGINE MECHANICAL - Cylinder Heed EM -27
.
..,.
(b) C heck the valve heed morgin.
Minimum
~In : lntoko 0.6
mm
10.020 in.)
E.th..,tt 1.0 mm 10.039 ln.)
If
the val ve head margin is less then specif ied. replace the
valve.
(cl Check the surface of the valve stem tip lor weer.
Standetd
Ove< . .
lentJth:
lnteko 107.6 mm (4.232 ln.)
E.th..,tl
109.7 mm (4 •. 3191n.l
If
the valve stem tip il worn, resurface the tip with a grinder
or replace the valve.
CAUTION: Do not grind more then 0.15 mm (0.020 ln.l .
12. INSPECT AND CLEAN VALVE SEATS
(a) Using o 45° carbide cutter, resurface the valve see11.
Remove only enough metal to clean the aeets.
(b) Check the valve aeating potition.
Apply e thin coat of pruuian blue (or white lead) to
the valve l ace. Install the valve. While applying l ight
pressure to the vetve, rotate
the
valve agelnst
the
seat.
(c) Check tho val ve lace and seat for the following:
• If blue appeara 360° around the face, t he valve i s
concentric.
If
not., replace the vatve .
• If blue IPJMitS 360° around the valve seat, the
guide and seat are concentJic. If not, resurface tile
seat .
• Check that the 1011 contact is on the middle of tho
valve face w ith
the
following width:
1.2 - 1.11 mm (0 .047 - 0.0631n.l
If not correct the valve seat as follow s:
If seating It too high on the valva lace, use 30°
and
46°
cutters to conee1 the eett.
If
seating is too low on the valve face, use 60°
(IN I or 67.5° (EX I and 45° cutters to correct tho
seat.