Kia Cerato 2009 Service Manual page 57

Valve stem outer diameter
Intake : 5.455 ~ 5.470mm (0.2148 ~ 0.2154in)
Exhaust : 5.435 ~ 5.450mm (0.2140 ~ 0.2146in)
(3) Subtract the valve stem outer diameter measurement from the valve guide inner diameter
measurement.
Valve stem- to-guide clearance
Intake : 0.030 ~ 0.057mm (0.0012 ~ 0.0022in)
Exhaust : 0.050 ~ 0.077mm (0.0020 ~ 0.0030in)
If the clearance is greater than specification, replace the valve and valve guide.
2. Inspect the valves.
(1) Check the valve is ground to the correct valve face angle.
(2) Check that the surface of valve for wear.
If the valve face is worn, replace the valve.
(3) Check the valve head margin thickness. If the margin thickness is less than specification, replace the
valve.
Margin
Intake : 1.1mm (0.0433in)
Exhaust : 1.2mm (0.0472in)