Orlando

Cylinder Head Cleaning and Inspection

Warning: Refer to Safety Glasses and Compressed Air Warning in the Preface section.

1. Inspect the cylinder head for the following:

•	Cracks, damage or pitting in the combustion chambers.

•	Debris in the oil galleries. Continue to clean the galleries until all debris is removed.

•	Coolant leaks or damage to the deck face sealing surface.

•	Damage to any gasket surfaces.

•	Damage to any threaded bolt holes.

•	Burnt or eroded areas in the combustion chamber.

•	Cracks in the exhaust ports and combustion chambers.

•	External cracks in the water passages.

•	Restrictions in the inlet or exhaust passages.

•	Restrictions in the cooling system passages.

•	Rusted, damaged or leaking core plugs.

2. If the cylinder head is cracked or damaged, it must be replaced. No welding or patching of the cylinder head is recommended.



3. Measure the clearance between the straight-edge and the cylinder head deck face, using a feeler gauge (1) at four points along the straight-edge.
4. Check the sealing surfaces for deformation and warpage. The cylinder head sealing surfaces must be flat within 0.05 mm (0.002 in) maximum.



5. Measure the height H of the cylinder head from sealing surface to sealing surface. The cylinder head height should be 129.9 to 130.1 mm (5.1142 to 5.1220 in).
6. If the cylinder head height is out of specifications, replace the cylinder head.

Valve Inspection

1. Inspect the valve for damage from the head to tip for the following conditions.

•	Inspect the valve faces for burning and cracking (1). If pieces are broken, replace the valve and inspect the corresponding piston and cylinder head area for damage.

•	Inspect the valve for straightness and distortion (2).

•	Inspect the valve stem for wear (3).

•	Inspect the valve key grooves for chipping and wear (4) and (5).

2. Replace the valve if any of these conditions exist.
3. Inspect the valve springs. If the valve spring ends are not parallel, replace the valve spring.
4. Inspect the valve spring seating surface of the valve rotators for wear or gouges. Replace as required.