Cylinder Head Assembly: Testing and Inspection

3UR-FBE ENGINE MECHANICAL: CYLINDER HEAD: INSPECTION

1. INSPECT CAMSHAFT OIL CLEARANCE

(a) Clean the bearing caps, camshaft housing and camshaft journals.

(b) Place the camshafts on the camshaft housing.

(c) Lay a strip of Plastigage across each of the camshaft journals.

(d) Install the camshaft bearing caps Installation.

NOTICE:
Do not turn the camshaft.

(e) Install the camshaft housing Installation.

NOTICE:
Do not turn the camshaft.

(f) Remove the camshaft bearing caps Removal.

(g) Measure the Plastigage at its widest point.

Standard Oil Clearance:

Maximum Oil Clearance:

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

2. INSPECT CAMSHAFT THRUST CLEARANCE

(a) Install the camshafts.

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

Standard thrust clearance:

0.08 to 0.135 mm (0.00315 to 0.00531 in.)

Maximum thrust clearance:

0.15 mm (0.00591 in.)

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

3. INSPECT COMPRESSION SPRING

(a) Using a vernier caliper, measure the free length of the inner compression spring.

Standard free length:

49.39 mm (1.94 in.)

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

(b) Using a steel square, measure the deviation of the inner compression spring.

Maximum deviation:

1.0 mm (0.0394 in.)

Maximum angle (reference):

2°

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

4. INSPECT INTAKE VALVE

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

Standard valve stem diameter:

5.470 to 5.485 mm (0.215 to 0.216 in.)

If the diameter is not as specified, replace the valve and guide bush.

(b) Using a vernier caliper, measure the valve head margin thickness.

Standard margin thickness:

1.10 to 1.40 mm (0.0433 to 0.0551 in.)

Minimum margin thickness:

0.50 mm (0.0197 in.)

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

(c) Using a vernier caliper, measure the valve's overall length.

Standard overall length:

105.85 mm (4.17 in.)

Minimum overall length:

105.35 mm (4.15 in.)

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

5. INSPECT EXHAUST VALVE

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

Standard valve stem diameter:

5.465 to 5.480 mm (0.215 to 0.216 in.)

If the diameter is not as specified, replace the valve and guide bush.

(b) Using a vernier caliper, measure the valve head margin thickness.

Standard margin thickness:

1.25 to 1.55 mm (0.0492 to 0.0610 in.)

Minimum margin thickness:

0.50 mm (0.0197 in.)

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

(c) Using a vernier caliper, measure the valve's overall length.

Standard overall length:

110.40 mm (4.35 in.)

Minimum overall length:

109.90 mm (4.33 in.)

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

6. INSPECT VALVE GUIDE BUSH OIL CLEARANCE

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

Standard bush inside diameter:

5.51 to 5.53 mm (0.217 to 0.218 in.)

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

Standard Oil Clearance:

Maximum Oil Clearance:

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

7. INSPECT INTAKE VALVE SEAT

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

(b) Lightly press the valve face against the valve seat.

HINT
Do not rotate the valve while pressing the valve.

(c) Check the valve face and valve seat.

(1) 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 1.1 to 1.5 mm (0.0433 to 0.0591 in.).

If not, correct the valve seat.

(2) 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.

8. INSPECT EXHAUST VALVE SEAT

(a) Using a precision straightedge and feeler gauge, measure the warpage of the surfaces where the cylinder head contacts the cylinder block and manifold.

Standard Warpage:

Maximum warpage:

0.10 mm (0.00394 in.)

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

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

If cracked, replace the cylinder head.