Cylinder Block

INSPECTION OF CYLINDER BLOCK
1. REMOVE GASKET MATERIAL
Using a gasket scraper, remove all the gasket material from the cylinder block surface.
2. CLEAN CYLINDER BLOCK
Using a soft brush and solvent, clean the block.

3. INSPECT TOP OF CYLINDER BLOCK FOR FLATNESS
Using a precision straight edge and thickness gauge, measure the surfaces contacting the cylinder head gasket for warpage.
Maximum warpage: 0.05 mm (0.0020 in.)
It warpage is greater than maximum, replace the cylinder block.

4. INSPECT CYLINDERS FOR VERTICAL SCRATCHES
Visually check the cylinder for vertical scratches.
It deep scratches are present, rebore all six cylinders. If necessary, replace the cylinder block.

5. INSPECT CYLINDER BORE DIAMETER

HINT: There are five sizes of standard cylinder bore diameter, marked "0", "1", "2", "3" and "4" accordingly. The mark is stamped on the cylinder block as shown in the illustration.

Using a cylinder gauge, measure the cylinder bore diameter at positions A, B and C in the thrust and axial directions.

Maximum cylinder bore diameter:
STD size 83.25 mm (3.2776 in.)
0/S 0.50
Maximum diameter 83.75 mm (3.2972 in.)
1987-88 Model
STD size 83.24 mm (3.2772 in.)
0/S 0.50
Maximum diameter83.74 mm (3.2968 in.)
1989-92 Model
If the diameter is greater than maximum, rebore all six cylinders. If necessary, replace the cylinder block.

6. REMOVE CYLINDER RIDGES
If the wear is less than 0.2 mm (0.008 in.), use a ridge reamer to machine the top of the cylinder.

DISASSEMBLY OF PISTON AND CONNECTING ROD ASSEMBLIES
1. CHECK FIT BETWEEN PISTON AND PIN Connecting Rod
Try to move the piston back and forth on the piston pin. If any movement is felt, replace the piston and pin as a set

2. REMOVE PISTON RINGS
(a) Using a piston ring expander, remove the compression rings.

(b) Remove the two side rails and oil ring expander by hand.

HINT: Arrange the rings in correct order.

3. DISCONNECT CONNECTING ROD FROM PISTON
(a) Using needle nose pliers, remove the snap rings from the piston.

(b) Gradually heat the piston to approx. 60°C (140°F).

(c) Using a plastic-faced hammer and brass bar, lightly tap out the piston pin and remove the connecting rod.

HINT: The piston and pin are a matched set. Arrange the pistons, pins, rings, connecting rods and bearings in correct order.

INSPECTION OF PISTON AND CONNECTING ROD ASSEMBLIES
1. CLEAN PISTON
(a) Using a gasket scraper, remove the carbon from the piston top.

(b) Using a groove cleaning tool or broken ring, clean the ring grooves.

2. INSPECT PISTON DIAMETER AND OIL CLEARANCE

HINT: There are five sizes of standard piston diameter, marked "0", "1", "2", "3" and "4" accordingly. The mark is stamped on the piston as shown in the illustration.

(a) Using a micrometer, measure the piston diameter at a right angle to the piston pin hole center line, 22 mm (0.87 in.) from the piston head.
Standard diameter
7M-GE 82.92-82.97 mm (3.2646-3.2665 in.)
7M-GTE 82.91-82.96 mm (3.2642-3.2661 in.)
1987-88 Model

1989-92 Model

(b) Measure the cylinder bore diameter in thrust directions.
(c) Subtract the piston diameter measurement from the cylinder bore diameter measurement.
Standard oil clearance:
7M-GE 0.08-0.10 mm (0.0031 - 0.0039 in.)
7M-GTE 0.07-0.09 mm (0.0028 - 0.0035 in.)
Maximum oil clearance: 0.13 mm (0.0051 in.)
1989-92 Model

If the oil clearance is greater than maximum, replace the piston. If necessary, rebore all six cylinders and replace all six pistons. If necessary, replace the cylinder block.

HINT: (Use cylinder block sub-assembly) When installing a standard piston, install one with the same mark as the standard bore diameter mark on the cylinder block.

3. INSPECT CLEARANCE BETWEEN WALL OF RING GROOVE AND NEW PISTON RING
Using a thickness gauge, measure the clearance between new piston ring and the wall of the piston ring groove.
Ring groove clearance: No.1 0.03-0.07 mm (0.0012 - 0.0028 in.) No.2 0.02-0.06 mm (0.0008 - 0.0024 in.)
If the clearance is not within specification, replace the piston.

4. INSPECT PISTON RING END GAP
(a) Insert the piston ring into the cylinder.
(b) Using a piston, push the ring a little beyond the bot torn of the ring travel.
(110 mm (4.33 in.) from the top surface of cylinder block)
(c) Using a thickness gauge, measure the end gap.

Ring end gap:1987-88 Model

Ring end gap:1989-92 Model

If the diameter is greater than maximum, rebore all six cylinders, or replace the cylinder block.
5. CHECK PISTON PIN FIT
At 60°C (140°F) you should be able to push the pin into the piston with your thumb.
If the pin can be installed at a lower temperature, replace the piston.

6. INSPECT CONNECTING ROD
(a) Using a rod aligner and thickness gauge, check the connecting rod alignment. Check for bend.
Maximum bend: 0.05 mm (0.0020 in.) per 100 mm (3.94 in.)
If bend is greater than maximum, replace the connecting rod assembly.

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

(b) Inspect the oil clearance between the rod bushing and piston pin. Using a caliper gauge, measure the inside diameter of the connecting rod bushing.
Bushing inside diameter:
Standard oil clearence: 0.005-0.011 mm (0.0002-0.0004 in.)
Maximum oil clearence: 0.02mm (0.0008 in.)
1987-88 Model
Bushing inside diameter: 22.005 - 22.017 mm (0.8663 - 0.8668 in.)
1989-92 Model

Using a micrometer, measure the piston pin diameter.
Piston pin diameter: 21.996 - 22.009 mm (0.8660 - 0.8665 in.)
Subtract the piston pin diameter measurement from the bushing inside diameter measurement.
Standard oil clearance: 0.005 0.011 mm (0.0002 - 0.0004 in.)
Maximum oil clearance: 0.02 mm (0.0008 in.)
If the oil clearance is greater than maximum, replace the bushing. If necessary, replace the piston and piston pin assembly.

7. IF NECESSARY, REPLACE CONNECTING ROD BUSHING
(a) Using SST and a press, press out the bushing. SST 09222-30010

(b) Align the oil holes of a new bushing and connecting rod.
(c) Using SST and a press, press in the bushing. SST 09222-30010

(d) Using a pin hole grinder, hone the bushing to obtain the specified clearance between the bushing and piston pin.

(e) Check the piston pin fit at normal room temperature. Coat the piston pin with engine oil and push it into the connecting rod with your thumb.