Part 3

ENGINE UNIT

COMPONENTS (Part 1):

COMPONENTS (Part 2):

COMPONENTS (Part 3):

COMPONENTS (Part 4):

COMPONENTS (Part 5):

COMPONENTS (Part 6):

COMPONENTS (Part 7):

INSPECTION(continued)

41. INSPECT PISTON DIAMETER
(a) Using a micrometer, measure the piston diameter at right angles to the piston center line, the indicated distance from the piston end.
Distance: 9.3 mm (0.366 inch)
Piston diameter: 94.941 to 94.971 mm (3.7378 to 3.7390 inch) (for standard)
42. INSPECT PISTON OIL CLEARANCE
(a) Measure the cylinder bore diameter in the thrust directions (see step 20).
(b) Subtract the piston diameter measurement from the cylinder bore diameter measurement.
Standard oil clearance: 0.019 to 0.052 mm (0.0007 to 0.0020 inch)
If the oil clearance is greater than the standard, replace all the pistons and rebore all the cylinders. If necessary, replace the cylinder block.

HINT:
^ Bore all the cylinders for the O/S piston outside diameter.
^ Replace all the piston rings with ones to match the O/S pistons.

(c) If the oil clearance is greater than the standard.
(1) Prepare 4 new O/S pistons.
O/S 0.50 piston diameter: 95.441 to 95.451 mm (3.7575 to 3.7579 inch)
(2) Using a micrometer, measure the piston diameter at right angles to the piston center line, the indicated distance from the piston end.
Distance: 9.3 mm (0.366 inch)
(3) Calculate the amount each cylinder is to be rebored as follows:
Size to be rebored = P + C - H

(4) Bore and hone the cylinders to calculated dimensions.
Maximum honing: 0.02 mm (0.0008 inch)

NOTICE: Excess honing will destroy the finished roundness.

43. INSPECT RING GROOVE CLEARANCE
(a) Using a feeler gauge, measure the clearance between a new piston ring and the wall of the ring groove.

Ring groove clearance:

If the clearance is not as specified, replace the piston.
44. INSPECT PISTON RING END GAP

(a) Insert the piston ring into the cylinder bore.
(b) 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.

Standard end gap:

Maximum end gap:

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, rebore all the 4 cylinders or replace the cylinder block.

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

(b) Using a micrometer, measure the piston pin diameter.
Piston pin diameter: 21.997 to 22.006 mm (0.8660 to 0.8664 inch)

(c) Using a caliper gauge, measure the inside diameter of the connecting rod bushing.
Bushing inside diameter: 22.005 to 22.014 mm (0.8663 to 0.8667 inch)
(d) Subtract the piston pin diameter measurement from the piton pin hole diameter measurement.
Standard oil clearance: 0.001 to 0.007 mm (0.00004 to 0.00028 inch)
Maximum oil clearance: 0.010 mm (0.0004 inch)

HINT: If the oil clearance is greater than the maximum, 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: 0.025 mm (0.0010 inch)
(f) If the oil clearance is greater than the maximum, replace the bushing. If necessary, replace the connecting rod and piston pin as a set.

46. INSPECT CONNECTING ROD
(a) Using a rod aligner and feeler gauge, check the connecting rod alignment.
(1) Check for bend.
Maximum bend: 0.03 mm (0.0012 inch) per 100 mm (3.94 inch)
If the bend is greater than the maximum, replace the connecting rod sub-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 sub-assembly.

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

48. INSPECT CRANKSHAFT
(a) Inspect for circle runout.
(1) Place the crankshaft 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 crankshaft.

(b) Inspect the main journals.
(1) Using a micrometer, measure the diameter of each main journal.

Standard journal diameter:

If the diameter is not as specified, check the oil clearance (see step 30). If necessary, replace the crankshaft.
(2) Check each main journal for taper and out-of-round as shown in the illustration.
Maximum taper and out-of-round: 0.005 mm (0.0002 inch)
If the taper and out-of-round is greater than the maximum, replace the crankshaft.

(c) Inspect the crank pin.
(1) Using a micrometer, measure the diameter of each crank pin.
Diameter: 52.989 to 53.002 mm (2.0862 to 2.0867 inch)
If the diameter is not as specified, check the oil clearance (see step 2). If necessary, replace the crankshaft.
(2) 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.
49. INSPECT CRANKSHAFT OIL CLEARANCE

HINT:
^ Keep the lower bearings and crankshaft bearing caps together.
^ Arrange the thrust washers in the correct order.
^ Keep the upper crankshaft bearings and upper thrust washers together with the cylinder block.

(a) Clean each main journal and bearing.
(b) Check each main journal and bearing for pitting and scratches.
If the journal or bearing is damaged, replace the bearing.
(c) Place the crankshaft on the cylinder block.

(d) Lay a strip of Plastigage across each journal.

(e) Install the 5 crankshaft bearing caps in their proper locations.
(f) Install the 5 crankshaft bearing caps with the 10 bolts (see step 49).

NOTICE: Do not turn the crankshaft.

(g) Remove the 10 bolts and 5 crankshaft bearing caps.

(h) Measure the Plastigage at its widest point.

Standard oil clearance:

Maximum oil clearance: 0.10 mm (0.0039 inch)
If the oil clearance is greater than the maximum, replace the crankshaft bearing.

HINT:
^ If replacing the cylinder block, measure the bearing standard clearance.
^ If replacing a bearing, first check the number on the cylinder block for the bearing's respective journal. Then replace the bearing with one that has the same number. Each bearing's standard thickness is indicated by a 1, 2 or 3 mark on its surface.

Reference

Cylinder block main journal bore diameter:

Standard bearing center wall thickness:

(i) Completely remove the Plastigage.

50. INSPECT CRANKSHAFT BEARING CAP SET BOLT
(a) Using vernier calipers, measure the minimum diameter of the compressed thread at the measuring point.
Standard diameter: 10.76 to 10.97 mm (0.4236 to 0.4319 inch)
Minimum diameter: 10.66 mm (0.4197 inch)
If the diameter is less than the minimum, replace the bolt.

51. INSPECT NO.1 BALANCE SHAFT
(a) Inspect the diameter of the journal.
(1) Using a micrometer, measure the diameter of the balance shaft main journals.

Main Journal Diameter:

(b) Inspect the diameter of bearing.
(1) Using a cylinder gauge, measure the inside diameter of the balance shaft bearing.

Bearing Inside Diameter:

(c) Inspect oil clearance.
(1) Subtract the balance shaft main journal diameter measurement from the balance shaft bearing inside diameter measurement.

Standard oil clearance:

Maximum oil clearance: 0.15 mm (0.0059 inch)
If the oil clearance is greater than the maximum, replace the cylinder block and balance shaft.

52. INSPECT NO.2 BALANCE SHAFT
(a) Inspect the diameter of the journal.
(1) Using a micrometer, measure the diameter of the balance shaft main journals.

Main Journal Diameter:

(b) Inspect the diameter of bearing.
(1) Using a cylinder gauge, measure the inside diameter of the balance shaft bearing.

Bearing Inside Diameter:

Standard Oil Clearance:

Maximum oil clearance: 0.15 mm (0.0059 inch)
If the oil clearance is greater than the maximum, replace the cylinder block and balance shaft.