Toyota 3R-B 1969, Repair Manual

Page: 37 / 193

3-10 E N G I N E - Major S e r v i c e
cylinder head r e a r plate.
F i g . 3-7 Cut-in of Water V4670
P ip e
Install the w a te r pipe so that the
mark provided at the end of the
w a te r pipe fa ces tow a rd s the valve
seat side.
2. Check the va lve seat fo r damage
and w e a r .
If n e c e s s a r y to r e fa c e , first check
the valve guide bushing fo r w e a r ,
and re p la ce the bushing if it is
w o r n , and then re fa c e the valve
seat with a valve seat grin d er o r
other cutters.
If the v a lv e cutter is used, three
different cutters of 15 , 45 and
75 a r e re q u ire d .
If these cutters a r e used, first,
using the 15 cutter, cut the seat
surface roughly. N e xt, use the
75
cutter, and cut the seat su r­
fa ce to approximate s iz e . Finally,
use the 45 cutter, and cut to
c o r r e c t s iz e .
Cut lightly to leave allowance fo r
F i g . 3-8 V a lv e S eat A n g le G1623
lapping the seat to obtain p r o p e r
width of 1.4 mm ( 0 . 0 5 5 " ) .
6. T h e valve seat angle is 4 5 °, and
the width is 1.4 mm ( 0 . 0 5 5 " ) . If
the width exceed s
1.4 mm o r
( 0 . 0 5 5 " ) , cut the bottom with the
■ M O Q
15 cutter and the upper with 75
cutter to obtain p r o p e r width.
7. A f t e r cutting, the valve should
contact the valve seat exactly at
the cen ter. T o check, apply a
thin coat of red lead on the seat,
and insert the v a lv e . Apply a light
p r e s s u r e on the valve to check
the contact. If the seating is too
high, use the 15
cutter and 45
cutter, and if too lo w , use the
75 cutter and 45 cutter.
8. L a p the valve and the seat with
a lapping compound to match the
seat. A f t e r lapping, clean the
v a lv e s and the valve seats tho­
roughly .
V a lv e Guide Bushing
1. Check the clearan ce between the
v a lve stem and the valve guide
bushing.
If the clea ran ce e x ceed s 0.1 mm
( 0 . 0 0 4 " ) , replace the valve and
the valve guide bushing with the
V a lv e Guide Bushing R e m o v e r &
R e p la c e r 09201-40010.
T h e specified clea ra n c es a re as
f o llo w s .
Intake s id e ’. 0.025 ~ 0.052 mm
( 0 . 0 0 1 0 - 0 . 0 0 2 0 ")
Exhaust side: 0.040 - 0 . 0 7 0 mm
(0.0016 ~ 0 .0 0 2 8 ")
T o check the clearan ce easily,
insert the valve into the guide bush­
ing , and move the valve stem to­
w a r d s the left and right.
If the movement at the valve stem
end e x c e ed s 0.25 mm ( 0 . 0 1 " ) ,
the clea ran ce may exceed 0 .1 mm
( 0 . 0 0 4 " ) .
2. Install the guide bushing into the
cylinder head so that the protrusion
of the guide bushing will be 23 mm