Engine Unit, Inspection

ENGINE UNIT

COMPONENTS:

INSPECTION

1. INSPECT OIL PUMP DRIVE SPROCKET
a. Wrap the chain around the drive gear.
b. Using a vernier caliper, measure the sprocket diameter with the chain.
Minimum sprocket diameter (w/chain): 48.2 mm (1.898 inch)

NOTICE: The vernier caliper must contact the chain rollers for the measurement. If the diameter is less than the minimum, replace the chain and sprocket.

2. INSPECT OIL PUMP DRIVEN SPROCKET
a. Wrap the chain around the drive shaft gear.
b. Using a vernier caliper, measure the sprocket diameter with the chain.
Minimum gear diameter (w/chain): 48.2 mm (1.898 inch)

NOTICE: The vernier caliper must contact the chain rollers for the measurement. If the diameter is less than the minimum, replace the chain and sprocket.

3. INSPECT CRANKSHAFT TIMING GEAR OR SPROCKET
a. Wrap the chain around the timing gear.
b. Using a vernier caliper, measure the timing gear diameter with the chain.
Minimum gear diameter (w/chain): 51.6 mm (2.031 inch)

NOTICE: The vernier caliper must contact the chain rollers for the measurement. If the diameter is less than the minimum, replace the chain and timing gear.

4. INSPECT CHAIN TENSIONER SLIPPER
a. Measure the tensioner slipper wear.
Maximum wear: 1.0 mm (0.039 inch)
If the wear is greater than the maximum, replace the tensioner slipper.

5. INSPECT CHAIN VIBRATION DAMPER NO. 1
a. Measure the vibration damper wear.
Maximum wear: 1.0 mm (0.039 inch)
If the wear is greater than the maximum, replace the vibration damper.

6. INSPECT CYLINDER HEAD SET BOLT
a. Using a vernier caliper, measure the length of the head bolts from the seat to the end.
Standard bolt length: 161.3 to 162.7 mm (6.3503 to 6.4055 inch)
Maximum bolt length: 164.2 mm (6.4646 inch)
If the length is greater than the maximum, replace the bolt.

7. INSPECT CHAIN TENSIONER ASSEMBLY NO. 1
a. Check that the plunger moves smoothly when the ratchet pawl is raised.
b. Release the ratchet pawl and check that the plunger is locked in place by the ratchet pawl and does not move when pushed with your finger.

8. INSPECT CHAIN SUB-ASSEMBLY
a. Using a vernier caliper, measure the length of 15 links with the chain fully stretched.
Maximum chain elongation: 115.4 mm (4.543 inch)

NOTICE: Make the same measurements pulling at 3 or more places selected at random. Average the measurements. If the elongation is greater than the maximum, replace the chain.

9. INSPECT CAMSHAFT TIMING GEAR OR SPROCKET
a. Wrap the chain around the timing sprocket.
b. Using a vernier caliper, measure the timing sprocket diameter with the chain.
Minimum sprocket diameter (w/chain): 97.3 mm (3.831 inch)

NOTICE: The vernier caliper must contact the chain rollers for the measurement. If the diameter is less than the minimum, replace the chain and timing gear.

10. INSPECT CAMSHAFT
a. Check the camshaft for runout.
(1) Place the camshaft on V-blocks.
(2) Using a dial indicator, measure the circle runout at the center journal.
Maximum circle runout: 0.03 mm (0.0012 inch)
If the circle runout is greater than the maximum, replace the camshaft.

b. Using a micrometer, measure the cam lobe height.
Standard cam lobe height: 46.495 to 46.595 mm (1.8305 to 1.8344 inch)
Maximum cam lobe height: 46.385 mm (1.8262 inch)
If the cam lobe height is less than the minimum, replace the camshaft.

c. Using a micrometer, measure the journal diameter.
No. 1 journal diameter: 35.971 to 35.985 mm (1.4162 to 1.4167 inch)
Other journal diameter: 22.959 to 22.975 mm (0.9039 to 0.9045 inch)
If the journal diameter is not as specified, check the oil clearance.

11. INSPECT NO. 2 CAMSHAFT
a. Check the camshaft for runout.
(1) Place the camshaft on V-blocks.
(2) Using a dial indicator, measure the circle runout at the center journal.
Maximum circle runout: 0.03 mm (0.0012 inch)
If the circle runout is greater than the maximum, replace the camshaft.

b. Using a micrometer, measure the cam lobe height.
Standard cam lobe height: 45.983 to 46.083 mm (1.8104 to 1.8143 inch)
Minimum cam lobe height: 45.873 mm (1.8060 inch)
If the cam lobe height is less than the minimum, replace the camshaft.

12. INSPECT CRANKSHAFT THRUST CLEARANCE
a. Using a dial indicator, measure the thrust clearance while prying the crankshaft back and forth with a screwdriver.
Standard thrust clearance: 0.040 to 0.240 mm (0.0016 to 0.0094 inch)
Maximum thrust clearance: 0.30 mm (0.0118 inch)
If the thrust clearance is greater than the maximum, replace the thrust washers as a set.
Thrust washer thickness: 1.930 to 1.980 mm (0.0760 to 0.0780 inch)

13. INSPECT CRANKSHAFT OIL CLEARANCE
a. Uniformly loosen and remove the 10 main bearing cap bolts, in the sequence shown in the illustration (Procedure "A").

b. Use 2 removed main bearing cap bolts to remove the 5 main bearing caps and 5 lower bearings (Procedure "B").

NOTICE: Insert the bolts into one of the caps. Ease the cap out by gently pulling up and applying force toward the front and back side of the cylinder block, as shown in the illustration. Take care not to damage the contact surfaces of the cap and cylinder block.

HINT:
^ Keep the lower bearing and main bearing cap together.
^ Arrange the main bearing caps in correct order.

c. Lift out the crankshaft.

HINT: Keep the upper bearings together with the cylinder block.

d. Clean each main journal and bearing.
e. Check each main journal and bearing for pitting and scratches.
If the journal or bearing is damaged, replace the bearings. If necessary, replace the crankshaft.

f. Place the crankshaft on the cylinder block.
g. Lay a strip of Plastigage across each journal.
h. Install the main bearing caps.

NOTICE: Do not turn the crankshaft.

i. Remove the main bearing cap (Procedure "A" to "B").

j. Measure the Plastigage at its widest point.
Standard oil clearance: 0.024 to 0.048 mm (0.00094 to 0.00189 inch)
If the oil clearance is greater than the maximum, replace the bearings. If necessary, replace the crankshaft.

k. If using a standard bearing, replace it with one having the same number. If the number of the bearing cannot be determined, select the correct bearing by adding together the numbers imprinted on the cylinder block and crankshaft, and then select the bearing according to the chart. There are 4 sizes of standard bearings: 1, 2, 3, and 4.

HINT:
EXAMPLE Cylinder block 4 (A) + Crankshaft 3 (B) = Total number 7 (Use bearing 3)

Reference:

l. Completely remove the Plastigage.
14. REMOVE CRANKSHAFT
a. Lift out the crankshaft.
b. Remove the 5 upper main bearings and 2 thrust washers from the cylinder block.

HINT: Arrange the main bearings and thrust washers in the correct order.

15. REMOVE CRANKSHAFT THRUST WASHER UPPER
16. REMOVE CRANKSHAFT BEARING

HINT: Arrange the bearings in the correct order.

17. REMOVE CRANKSHAFT BEARING NO. 2

HINT: Arrange the main bearings and thrust washers in the correct order.

18. REMOVE STUD BOLT
19. CLEAN CYLINDER BLOCK

NOTICE: If the cylinder is washed at high temperatures, the cylinder liner sticks out beyond the cylinder block. Always wash the cylinder block at a temperature of 45°C (113°F) or less.

20. INSPECT CYLINDER BLOCK FOR FLATNESS
a. Using a precision straight edge and feeler gauge, measure the surface contacting the cylinder head gasket for warpage.
Maximum warpage: 0.05 mm (0.0020 inch)
If the warpage is greater than the maximum, replace the cylinder block.

21. INSPECT CYLINDER BORE
a. Using a cylinder gauge, measure the cylinder bore diameter at positions A and B in the thrust and axial directions.
Standard diameter: 88.500 to 88.513 mm (3.4842 to 3.4848 inch)
Maximum diameter: 88.633 mm (3.4895 inch)
If the measured diameters is greater than the standard, replace the cylinder block.

22. INSPECT PISTON DIAMETER
a. Using a micrometer, measure the piston diameter at right angles to the piston pin center line, 30.3 mm (1.193 inch)from the piston head.
Piston diameter: 88.439 to 88.449 mm (3.4818 to 3.4822 inch)
23. INSPECT PISTON CLEARANCE
a. Subtract the piston diameter measurement from the cylinder bore diameter measurement.
Specified oil clearance: 0.051 to 0.100 mm (0.0020 to 0.0039 inch)
If the clearance is greater than the maximum, replace all the 4 pistons. If necessary, replace the cylinder block.

24. INSPECT RING GROOVE CLEARANCE
a. Using a feeler gauge, measure the clearance between the piston ring and the wall of the ring groove.
Ring groove clearance: 0.030 to 0.070 mm (0.0012 to 0.0028 inch)
If the clearance is not as specified, replace the piston.

25. INSPECT PISTON RING END GAP
a. Using a piston, push the piston ring a little beyond the bottom of the ring travel, 110 mm (4.33 inch)from the top of the cylinder block.

b. Using a feeler gauge, measure the end gap.
Standard end gap:
No. 1 0.22 to 0.32 mm (0.0087 to 0.0126 inch)
No. 2 0.50 to 0.60 mm (0.0197 to 0.0236 inch)
Oil (side rail) 0.10 to 0.35 mm (0.0039 to 0.0138 inch)
Maximum end gap:
No. 1 0.89 mm (0.0350 inch)
No. 2 1.35 mm (0.0531 inch)
Oil (side rail) 0.73 mm (0.0287 inch)
If the end gap is greater than the maximum, replace the piston ring. If the end gap is greater than the maximum even with a new piston ring, replace the cylinder block.

26. INSPECT PISTON PIN OIL CLEARANCE
a. Using a caliper gauge, measure the inside diameter of the piston bushing.
Pin hole bush diameter: 22.001 to 22.010 mm (0.8662 to 0.8665 inch)

Pin Hole Bush Diameter (Reference):

b. Using a micrometer, measure the piston pin diameter.
Piston pin diameter: 21.997 to 22.009 mm (0.8660 to 0.8665 inch)

Piston Pin Diameter (Reference):

c. Using a caliper gauge, measure the inside diameter of the connecting rod bush.
Bush inside diameter: 22.005 to 22.014 mm (0.8663 to 0.8667 inch)

Bush Inside Diameter:

d. Subtract the piston pin diameter measurement from the piton pin bush hole diameter measurement.
Standard oil clearance: 0.001 to 0.007 mm (0.00004 to 0.00028 inch)
Maximum oil clearance: 0.010 mm (0.0020 inch)
If the oil clearance is greater than maximum, replace the connecting rod. If necessary, replace the piston and piston pin as a set.

e. Subtract the piston pin diameter measurement from the bushing inside diameter measurement.
Standard oil clearance: 0.005 to 0.011 mm (0.0002 to 0.0004 inch)
Maximum oil clearance: 0.010 mm (0.0020 inch)
If the oil clearance is greater than the maximum, replace the connecting rod. If necessary, replace the connecting rod and piston pin as a set.

27. INSPECT CONNECTING ROD SUB-ASSEMBLY
a. Using a rod aligner and feeler gauge, check the connecting rod alignment.
(1) Check for out-of-alignment.
Maximum out-of-alignment: 0.05 mm (0.0020 inch) per 100 mm (3.94 inch)
If the out-of-alignment is greater than the maximum, replace the connecting rod assembly

(2) Check for twist.
Maximum twist: 0.15 mm (0.0059 inch) per 100 mm (3.94 inch)
If the twist is greater than the maximum, replace the connecting rod assembly.

28. INSPECT CONNECTING ROD BOLT
a. Using a vernier caliper, measure the tension portion diameter of the bolt.
Standard diameter: 7.2 to 7.3 mm (0.283 to 0.287 inch)
Maximum diameter: 7.0 mm (0.276 inch)
If the diameter is less than the minimum, replace the bolt.

29. INSPECT CRANKSHAFT
a. Using a dial indicator and V-blocks, measure the circle runout, as shown in the illustration.
Maximum circle runout: 0.03 mm (0.0012 inch)
If the circle runout is greater than the maximum, replace the crankshaft.

b. Using a micrometer, measure the diameter of each main journal.
Diameter: 54.988 to 55.000 mm (2.16488 to 2.16535 inch)
If the diameter is not as specified, check the oil clearance. If necessary, replace the crankshaft.
c. Check each main journal for taper and out-of-round as shown in the illustration.
Maximum taper and out-of-round: 0.003 mm (0.0001 inch)
If the taper and out-of-round is greater than the maximum, replace the crankshaft.

Diameter (Reference):

d. Using a micrometer, measure the diameter of each crank pin.
Diameter: 47.990 to 48.000 mm (1.8894 to 1.8898 inch)
If the diameter is not as specified, check the oil clearance. If necessary, replace the crankshaft.
e. Check each crank pin for taper and out-of-round as shown in the illustration.
Maximum taper and out-of-round: 0.003 mm (0.0001 inch)
If the taper and out-of-round is greater than the maximum, replace the crankshaft.

30. INSPECT CRANKSHAFT BEARING CAP SET BOLT
a. Using a vernier caliper, measure the tension portion diameter of the bolt.
Standard diameter: 7.3 to 7.6 mm (0.287 to 0.299 inch)
Minimum diameter: 7.2 mm (0.283 inch)
If the diameter is less than the minimum, replace the bolt.