Cylinder Head Clean and Inspect
CLEANING PROCEDURE- Tools Required
- J 8089 Carbon Removing Brush
CAUTION: Wear safety glasses in order to avoid eye damage.
IMPORTANT: Mark, sort, or organize components for return to their original locations.
1. Clean the valve heads on a buffing wheel.
2. Clean the following components in solvent
- Valve stem keys (1)
- Valve spring cap (2)
- Valve spring (4)
- Valve rotators (5)
- Valve (6)
- Cylinder head
CAUTION: Wear safety glasses in order to avoid eye damage.
3. Dry the components with compressed air.
IMPORTANT: Be careful not to scuff the chamber or damage the valve seat.
4. Use the J 8089 in order to clean the carbon from the combustion chambers.
VISUAL INSPECTION PROCEDURE
Inspect the cylinder head for the following conditions:
- Damaged gasket surfaces
- Damage to threaded bolt holes
- Burnt or eroded areas in the combustion chamber
- Cracks in the exhaust ports and combustion chambers
- External cracks in the water chamber
- Restrictions in the intake or exhaust passages
- Restrictions in the cooling system passages
FLATNESS MEASUREMENT PROCEDURE
1. Measure the cylinder head for warpage with a straight edge and feeler gauge.
- A cylinder head block deck with warpage in excess of 0.076 mm (0.003 inch) within a 152.4 mm (6.0 inch) area must be repaired or replaced.
- A cylinder head exhaust manifold deck with an overall warpage in excess of 0.152 mm (0.006 inch) must be repaired or replaced.
- A cylinder head intake manifold deck with warpage in excess of 0.10 mm (0.004 inch) must be repaired or replaced.
2. A cylinder head block deck can be resurfaced up to 0.305 mm (0.012 inch) maximum removal.
IMPORTANT: Excessive cylinder head resurfacing will affect compression ratio and emission control.
3. A cylinder head that requires excessive resurfacing must be replaced.
VALVE INSPECTION PROCEDURE
1. Inspect the valves for the following conditions:
- Burnt or damaged areas (1)
- Undersized valve margin (2)
- Bent stem (3)
- Wear, scoring or other damage to the stem (4)
- Worn key groove (5)
- Worn stem tip (6)
2. Inspect the valve contact surface for the following conditions:
- Undersized margin (1)
- Pitted surface (2)
- Burnt or eroded areas (3)
- Acceptable edge (margin) (4)
IMPORTANT: Minor imperfections of the valve may be corrected during reconditioning.
3. Valves with excessive damage must be replaced.
VALVE SPRING INSPECTION AND MEASUREMENT
^ Tools Required
- J 9666 Valve Spring Tester
1. Inspect the valve springs for broken coils or coil ends.
2. Use the J 9666 in order to measure the valve spring tension.
IMPORTANT: Add a maximum of one shim up to 0.726 mm (0.030 inch) thick to increase tension.
3. If low valve spring tension is found, use a shim to increase tension.
4. Recheck the valve spring tension, a valve spring that does not meet specification must be replaced.
VALVE GUIDE MEASUREMENT PROCEDURE
^ Tools Required
- J 8001 Dial Indicator Set
IMPORTANT: Excessive valve stem-to-guide clearance may cause an excessive oil consumption and may also cause a valve to break. Insufficient clearance will result in noisy and sticky functioning of the valve and will disturb the engine assembly smoothness.
1. Measure the valve stem-to-guide clearance.
Clamp the J 8001 on the exhaust port side of the cylinder head.
IMPORTANT: The indicator stem must contract the side of the valve stem just above the valve guide.
^ Locate the indicator so that the movement of the valve stem from side to side (crosswise to the cylinder head) will cause a direct movement of the indicator stem.
^ Drop the valve head about 1.6 mm (0.064 inch) off the valve seat.
^ Use light pressure when moving the valve stem from side to side in order to obtain a clearance reading.
2. A valve guide (2) with excessive clearance must be repaired.
3. Replace the cylinder head if the valve guide cannot be repaired.