Inspection

Inspection

Cylinder Head
1. Inspect for flatness.
Using a precision straight edge and feeler gauge, measure the surface contacting cylinder block and the manifolds for warpage.

Flatness of cylinder head gasket surface
Standard : Less than 0.05mm(0.002in)
[Less than 0.02mm(0.0008in)/100x100]
Flatness of manifold gasket surface
Standard : Less than 0.1mm(0.004in)
[Less than 0.03mm(0.0012in)/110x110]





2. Inspect for cracks.
Check the combustion chamber, intake ports, exhaust ports and cylinder block surface for cracks. If cracked, replace the cylinder head.

Valve And Valve Spring
1. Inspect valve stems and valve guides.
(1) Using a caliper gauge, measure the inside diameter of the valve guide.

Valve guide I.D.
Intake / Exhaust :
6.000 - 6.012mm (0.2362 - 0.2367in)





(2) Using a micrometer, measure the diameter of the valve stem.

Valve stem O.D.
Intake : 5.965 - 5.980mm (0.2348 - 0.2354in)
Exhaust : 5.958 - 5.970mm (0.2346 - 0.2350in)





(3) Subtract the valve stem diameter measurement from the valve guide inside diameter measurement.

Valve stem-to-guide clearance
Intake : 0.020 - 0.047mm (0.0008 - 0.0018in)
Exhaust : 0.030 - 0.054mm (0.0012 - 0.0021in)


2. Inspect valves.
(1) Check the valve is ground to the correct valve face angle.

Valve face angle :
Intake/Exhaust : 45.25°~ 45.75°


(2) Check that the surface of the 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 minimum, replace the valve.

Margin
Intake : 1.2mm (0.0472in)
Exhaust : 1.2mm (0.0472in)





(4) Check the valve length.

Length
Intake : 107.77mm (4.2429in)
Exhaust : 107.75mm (4.2421in)


(5) Check the surface of the valve stem tip for wear.If the valve stem tip is worn, replace the valve.
3. Inspect valve seats.
(1) Check the valve seat for evidence of overheating and improper contact with the valve face.
If the valve seat is worn, replace cylinder head.
(2) Before reconditioning the seat, check the valve guide for wear. If the valve guide is worn, replace cylinder head.
(3) Recondition the valve seat with a valve seat grinder or cutter. The valve seat contact width should be within specifications and centered on the valve face.

Valve seat contact width :
Intake : 1.15 - 1.45mm (0.0453 - 0.0571in)
Exhaust : 1.35 - 1.65mm (0.0531 - 0.0650in)
Valve seat angle :
Intake/Exhaust : 44.75°~ 45.10°


4. Inspect valve springs.
(1) Using a steel square, measure the out-of-square of the valve spring.
(2) Using vernier calipers, measure the free length of the valve spring.

Valve spring
Free height : 47.8mm (1.8819in)
Out-of-square : 1.5°






Camshaft
1. Inspect cam lobes.
Using a micrometer, measure the cam lobe height.

Cam height
Intake : 41.6mm (16.4in)
Exhaust : 41.5mm (16.3in)





If the cam lobe height is less than standard, replace the camshaft.
2. Inspect the camshaft journal clearance.
(1) Clean the bearing caps and camshaft journals.
(2) Place the camshafts on the cylinder head.
(3) Lay a strip of plastigage across each of the camshaft journals.