Valve Seats - Honda Civic Service Manual

Valve Seats
Reconditioning
1. Renew the valve seats in the cylinder
valve seat cutter.
N O T E : l f a n y g u i d e s a r e w o r n ( s e e
r e p l a c e t h e m ( s e e p a g e 6 - 8 0 ) b e f o r e
valve seats,
head with a
p a g e 6 - 7 9 ) ,
c u t t i n g t h e
Carefully cut a 45o seat, removing only enough mate-
rial to ensure a smooth and concentric seat.
Bevel the upper edge of the seat with the 30" cutter
and the lower edge of the seat with the 60. cutter.
Check width of seat and adjust accordingly,
Make one more very light pass with the 45" cutter to
remove any possible burrs caused bv the other cut-
ters.
Valve Seat Width:
Standard (Newl: 1.25 - 1.55 mm {0.0't9 - 0.061 in)
Service Limii: 2.0 mm 10,08 inl
Sear Widrh
6-78
5. After resufacing the seat. inspect for even valve
s e a t i n g : A p p l y P r u s s i a n B l u e C o m p o u n d t o t h e
valve face, and insert the valve in its original loca-
t i o n i n t h e h e a d . t h e n l i f t i t a n d s n a p i t c l o s e d
against the seat several times.
PRUSSIAN BLUE COMPOUND
The actual valve seating surface, as shown by the
blue compound, should be centered on the seat.
. lf it is too high (closer to the valve stem), you must
make a second cut with the 60. cutter to move it
down, then one more cut with the 45. cutter to
restore seat width.
. lf it is too low (closer to the valve edge), you must
make a second cut with the 30. cutter to move it
up. then one more cut with the 45. cutter to restore
seat width.
NOTE: The final cut should always be made with
the 45" cutter,
7. Insen the intake and exhaust valves in the head and
measure valve stem installed heioht.
Intaka Valve Stem Installed Height:
Standsrd lNaw): 37.465 - 37.935 mm
(1./P50 - r.4935 inl
Sorvice Limit:
38.185 mm 0.5033 in)
Exhau3t Valv€ Stem Installed Height:
Standard (New): 37.165 - 37.6i|5 mm
(1.46:t2 - 1.i1817 inl
Servico Limit
37.885 (1.4915 inl
lf valve stem installed height is over the service limit,
replace the valve and recheck. lf it is still over the ser-
vice limit, replace the cylinder head; the valve seat in
the h6ad is too deep.
(