Valve Seat Reconditioning - Honda Accord 2008 Manual

07/11/02 09:25:48 61TA0000_060_0094
Cylinder Head

Valve Seat Reconditioning

1. Inspect the valve stem-to-guide clearance
(see page 6-91). If the valve guides are worn,
replace them (see page 6-92) before cutting the
valve seats.
2. Renew the valve seats in the cylinder head using a
valve seat cutter.
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3. Carefully cut a 45 ° seat, removing only enough
material to ensure a smooth and concentric seat.
4. Bevel the upper and lower edges at the angles
shown in the illustration.
Check the width of the seat and adjust accordingly.
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6-94
5. Make one more very light pass with the 45 ° cutter
6. After resurfacing the seat, inspect for even valve
7. The actual valve seating surface (B), as shown by
INTAKE: 35 °
EXHAUST: 30 °
45 °
67.5 °
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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.)
seating. Apply Prussian Blue compound (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.
B
A
the shaded area, should be centered on the seat.
• If it is too high (closer to the valve stem), you
must make a second cut with the 67.5 ° cutter to
move it down, then one more cut with the 45 °
cutter to restore seat width.
• If it is too low (close to the valve edge), you must
make a second cut with the 35 ° cutter (intake
side) or the 30 ° cutter (exhaust side) to move it
up, then make one more cut with the 45 ° cutter
to restore seat width.
NOTE: The final cut should always be made with
the 45 ° cutter.
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