ГОЛОВКА БЛОКА ЦИЛИНДРОВ ПРОВЕРКА

INSPECT CYLINDER HEAD FOR FLATNESS

1. Using a precision straightedge and feeler gauge, measure the warpage of the contact surfaces where the cylinder head contacts the cylinder block and manifolds.

   

   Maximum Warpage
   Item Specified Condition Cylinder block side 0.05 mm (0.00197 in.) Intake manifold side 0.10 mm (0.00394 in.) Exhaust manifold side 0.10 mm (0.00394 in.)

   If the warpage is more than the maximum, replace the cylinder head.

INSPECT CYLINDER HEAD FOR CRACKS

1. Using a dye penetrant, check the intake ports, exhaust ports and cylinder surface for cracks.

   

   If cracked, replace the cylinder head.

INSPECT VALVE SEATS

1. Apply a light coat of Prussian blue to the valve face.

   

2. Lightly press the valve face against the valve seat.

   Tech Tips

   Do not rotate the valve while pressing the valve.

3. Check the valve face and valve seat.

   1. Intake Side:

      Check that the contact surfaces of the valve seat and valve face are in the middle area of their respective surfaces, with the width between 1.0 and 1.4 mm (0.0394 and 0.0551 in.).

      If not, correct the valve seat.

   2. Exhaust Side:

      Check that the contact surfaces of the valve seat and valve face are in the middle area of their respective surfaces, with the width between 1.0 and 1.4 mm (0.0394 and 0.0551 in.).

      If not, correct the valve seat.

   3. Check that the contact surfaces of the valve seat and valve face are even around the entire valve seat.

      If not, correct the valve seat.

INSPECT CAMSHAFT THRUST CLEARANCE

1. Install the camshaft Click here.

   Tech Tips

   Do not use seal packing when installing the camshaft housing, as the installation is temporary.

2. Using a dial indicator, measure the thrust clearance while moving the camshaft back and forth.

   

   Standard thrust clearance
   0.06 to 0.155 mm (0.00236 to 0.00610 in.)

   Maximum thrust clearance
   0.17 mm (0.00669 in.)

   If the thrust clearance is more than the maximum, replace the camshaft housing sub-assembly. If the thrust surface is damaged, replace the camshaft.

INSPECT CAMSHAFT OIL CLEARANCE

1. Clean the bearing caps and camshaft journals.

2. Place the camshafts on the camshaft housing.

   Tech Tips

   Do not use seal packing when installing the camshaft housing, as the installation is temporary.

3. Lay a strip of Plastigage across each of the camshaft journals.

   

   Text in Illustration

   *1	Plastigage

4. Install the bearing caps Click here.

   Note

   Do not turn the camshaft.

5. Remove the bearing caps Click here.

6. Measure the Plastigage at its widest point.

   

   Text in Illustration

   *1	Plastigage

   Standard Oil Clearance
   Item Specified Condition Camshaft No. 1 Journal 0.030 to 0.063 mm (0.00118 to 0.00248 in.) Camshaft Other Journals 0.035 to 0.072 mm (0.00138 to 0.00283 in.)

   Maximum Oil Clearance
   Item Specified Condition Camshaft No. 1 Journal 0.085 mm (0.00335 in.) Camshaft Other Journals 0.09 mm (0.00354 in.)

   Note

   Completely remove the Plastigage after the inspection.

   If the oil clearance is more than the maximum, replace the camshaft. If necessary, replace the cylinder head.

INSPECT COMPRESSION SPRING

1. Using a vernier caliper, measure the free length of the compression spring.

   

   Standard free length
   53.36 mm (2.10 in.)

   If the free length is not as specified, replace the compression spring.

2. Using a steel square, measure the deviation of the compression spring.

   

   Maximum deviation
   1.0 mm (0.0394 in.)

   If the deviation is more than the maximum, replace the compression spring.

INSPECT INTAKE VALVE

1. Using a vernier caliper, measure the overall length of the valve.

   

   Standard overall length
   109.34 mm (4.30 in.)

   Minimum overall length
   108.84 mm (4.29 in.)

   If the overall length is less than the minimum, replace the valve.

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

   

   Valve stem diameter
   5.470 to 5.485 mm (0.215 to 0.216 in.)

   If the valve stem diameter is not as specified, check the oil clearance.

3. Using a vernier caliper, measure the valve head margin thickness.

   

   Standard margin thickness
   1.0 mm (0.0394 in.)

   Minimum margin thickness
   0.5 mm (0.0197 in.)

   If the margin thickness is less than the minimum, replace the valve.

INSPECT EXHAUST VALVE

1. Using a vernier caliper, measure the overall length of the valve.

   

   Standard overall length
   108.25 mm (4.26 in.)

   Minimum overall length
   107.75 mm (4.24 in.)

   If the overall length is less than the minimum, replace the valve.

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

   

   Valve stem diameter
   5.465 to 5.480 mm (0.215 to 0.216 in.)

   If the valve stem diameter is not as specified, check the oil clearance.

3. Using a vernier caliper, measure the valve head margin thickness.

   

   Standard margin thickness
   1.0 mm (0.0394 in.)

   Minimum margin thickness
   0.5 mm (0.0197 in.)

   If the margin thickness is less than the minimum, replace the valve.

INSPECT VALVE GUIDE BUSH OIL CLEARANCE

1. Using a caliper gauge, measure the inside diameter of the guide bush.

   

   Standard bushing inside diameter
   5.510 to 5.530 mm (0.217 to 0.218 in.)

2. Subtract the valve stem diameter measurement from the guide bush inside diameter measurement.

   Standard Oil Clearance
   Item Specified Condition Intake 0.025 to 0.060 mm (0.000984 to 0.00236 in.) Exhaust 0.030 to 0.065 mm (0.00118 to 0.00256 in.)

   Maximum Oil Clearance
   Item Specified Condition Intake 0.080 mm (0.00315 in.) Exhaust 0.085 mm (0.00335 in.)

   If the clearance is more than the maximum, replace the valve and guide bush.