Honda ACCORD HYBRID 2005 Service Manual page 156

Cylinder Head
V a l v e S e a t R e c o n d i t i o n i n g
1. Inspect valve stem-to-guide clearance (see page
6-51). If the valve guides are w o r n , replace t h e m
(see page 6-52) before cutting the valve seats.
2. Renew the valve seats in the cylinder head using a
valve seat cutter.
3. Carefully cut a 45 ° seat, r e m o v i n g only enough
material to ensure a s m o o t h and concentric seat.
4. Bevel the upper edge of the seat w i t h the 30 ° cutter
and the lower edge of the seat w i t h the 67.5 ° cutter
(intake seat) or the 60 ° cutter (exhaust seat). Check
the w i d t h of the seat and adjust accordingly.
5. Make one more very light pass w i t h the 45 ° cutter
to remove any possible burrs caused by the other
cutters.
Valve Seat Width
Standard (New): 1.25—1.55 mm (0.049-0.061 in.)
Service Limit: 2.00 mm (0.079 in.)
6. After resurfacing the seat, inspect it for even valve
seating: A p p l y Prussian Blue c o m p o u n d (A) to the
valve face. Insert the valve in its original location in
the head, then lift it and snap it closed against the
seat several times.
i
7. The actual valve seating surface (B), as s h o w n by
the blue c o m p o u n d , should be centered on the seat.
• If it is too high (closer to the valve stem), you
must make a second cut w i t h the 67.5 ° cutter
(intake seat) or the 60 ° cutter (exhaust seat) to
move it d o w n , then one m o r e cut w i t h the 45 °
cutter to restore seat w i d t h .
• If it is too low (closer to the valve edge), y o u must
make a second cut w i t h the 30 ° cutter to move it
up, then one more cut w i t h the 45 ° cutter to
restore seat w i d t h .
NOTE: The final cut should always be made w i t h
the 45 ° cutter.
6-54