Toyota 4Y 2006 Manual page 54

Inspection:
Inspect the valves.
1.
Measure the wall thickness of the valve head.
Standard
IN: I .0 to 1.4 mm (0.039 to 0.055 in.)
EX: 1.3 to 1.7 mm (0.051 to 0.067 in.)
Limit
IN: 0.5 mm (0.020 in.)
EX: 0.8 mm (0.031 in.)
2.
Measure the total length of the valves.
Standard
IN: 108.2 mm (4.260 in.)
EX: 108.5 mm (4.272 in.)
Limit
IN: 107.7 mm (4.240 in.)
EX: 108.0 mm (4.252 in.)
Inspection:
lnspect the valve seat
1. Apply red lead primer thinly to the valve face.
2.
Insert the valve into the valve guide bushing, and press the
valve onto the valve seat. Do not rotate the valve while it is
pressed onto the valve seat.
3. lnspect the width of the contact surface to see whether it is
within the standard along the entire circumference.
Standard
Contact width: 1.2 to 1.6 mm (0.047 to 0.063 in.)
If the width is not within the standard, replace the valve or
correct the valve seat.
4. Correct the valve seat.
Caution:
Use a carbide tip cutter for the EX side.
Cutting should be performed while constantly checking
the contact point and contact width of the valve.
In order not to create steps, gradually reduce the force
towards the end of cutting.
Make corrections after inspecting the valve guide
bushing.