SAAB WIS ONLINE

INSPECTION

INSPECTION

CYLINDER BLOCK

Visually check for cracks and damage. Especially, inspect the important parts by means of red lead check.

Check the oil passages for clogging.

Inspect the crankcase surface that mates with cylinder head for warping by using a straight edge, and correct by grinding if necessary.

Warping limit:

0.025 mm (0.00098 in)

Grinding limit:

0.1 mm (0.004 in)

Standard height of cylinder block:

201.0 mm (7.91 in)

CYLINDER AND PISTON

The cylinder bore size is stamped on cylinder block’s front upper surface.

Note
• Measurement should be performed at a temperature of 20°C (68°F).

• Standard sized pistons are classified into two grades, “A” and “B”. These grades should be used as a guide line in selecting a standard piston.


Standard diameter:

A: 92.005 — 92.015 mm (3.6222 — 3.6226 in)

B: 91.995 — 92.005 mm (3.6218 — 3.6222 in)


(A)

Main journal size mark

(B)

Cylinder block (RH)-(LH) combination mark

(C)

#1 cylinder bore size mark

(D)

#2 cylinder bore size mark

(E)

#3 cylinder bore size mark

(F)

#4 cylinder bore size mark



How to measure the inner diameter of each cylinder:

Measure the inner diameter of each cylinder in both the thrust and piston pin directions at the heights shown in the figure, using a cylinder bore gauge.

Note

Measurement should be performed at a temperature of 20°C (68°F).


Taper:

Standard

0.015 mm (0.0006 in)

Out-of-roundness:

Standard

0.010 mm (0.0004 in)


(A)

Piston pin direction

(B)

Thrust direction

H1:

10 mm (0.39 in)

H2:

45 mm (1.77 in)

H3:

80 mm (3.15 in)

H4:

115 mm (4.53 in)



When the piston is to be replaced due to general or cylinder wear, determine a suitable sized piston by measuring the piston clearance.

How to measure the outer diameter of each piston:

Measure the outer diameter of each piston at the height shown in the figure. (Thrust direction)

Note

Measurement should be performed at a temperature of 20°C (68°F).


Piston grade point H:

40.0 mm (1.57 in)

Piston outer diameter:

Standard

A: 91.985 — 91.995 mm (3.6214 — 3.6218 in)

B: 91.975 — 91.985 mm (3.6211 — 3.6214 in)

0.25 mm (0.0098 in) oversize

92.225 — 92.235 mm (3.6309 — 3.6313 in)

0.50 mm (0.0197 in) oversize

92.475 — 92.485 mm (3.6407 — 3.6411 in)


Calculate the clearance between cylinder and piston.

Note

Measurement should be performed at a temperature of 20°C (68°F).


Cylinder to piston clearance at 20°C (68°F):

Standard

0.010 — 0.030 mm (0.0004 — 0.0012 in)

Boring and honing:

If the value of taper, out-of-roundness, or cylinder-to-piston clearance measured exceeds the standard or if there is any damage on the cylinder wall, reboring it to use an oversize piston.

Important

When any of the cylinders needs reboring, all other cylinders must be bored at the same time, and use oversize pistons. Do not perform boring on one cylinder only, nor use an oversize piston for one cylinder only.


If the cylinder inner diameter exceeds the limit after boring and honing, replace the crankcase.

Note

Immediately after reboring, the cylinder diameter may differ from its real diameter due to temperature rise. Thus, pay attention to this when measuring the cylinder diameter.


Limit of cylinder enlarging (boring):

0.5 mm (0.020 in)

PISTON AND PISTON PIN

Check the pistons and piston pins for damage, cracks, and wear and the piston ring grooves for wear and damage. Replace if defective.

Measure the piston-to-cylinder clearance at each cylinder. If any of the clearances is not within specification, replace the piston or bore the cylinder to use an oversize piston.

Make sure that the piston pin can be inserted into the piston pin hole with a thumb at 20°C (68°F). Replace if defective.

Standard clearance between piston pin and hole in piston:

Standard

0.004 — 0.008 mm (0.0002 — 0.0003 in)



Check the snap ring installation groove on piston for burr (A). If necessary, remove the burr from groove so that the piston pin can lightly move.


Check the piston pin snap ring for distortion, cracks and wear.

PISTON RING

If the piston ring is broken, damaged, or worn, or if its tension is insufficient, or when the piston is replaced, replace the piston ring with a new one of the same size as the piston.

Important
• Marks are shown on the end of top and second rings. When installing the rings to piston, face this mark upward.

• Oil ring consists of upper rail, expander and lower rail. When installing on piston, be careful of each rail’s direction.



(A)

Upper rail

(B)

Expander

(C)

Lower rail



Squarely place the piston ring and oil ring in cylinder, and then measure the piston ring gap with a thickness gauge.

Unit: mm (in)

Standard

Piston ring gap

Top ring

0.20 — 0.25

(0.0079 — 0.0098)

Second ring

0.40 — 0.50

(0.0157 — 0.0197)

Oil ring rail

0.20 — 0.50

(0.0079 — 0.0197)




Measure the clearance between piston ring and piston ring groove with a thickness gauge.

Note

Before measuring the clearance, clean the piston ring groove and piston ring.

Unit: mm (in)

Standard

Clearance between piston ring and piston ring groove

Top ring

0.040 — 0.080

(0.0016 — 0.0031)

Second ring

0.030 — 0.070

(0.0012 — 0.0028)





CONNECTING ROD

Replace the connecting rod, if the large or small end thrust surface is damaged.

Check for bend or twist using a connecting rod aligner. Replace the connecting rod if the bend or twist exceeds the limit.

Limit of bend or twist per 100 mm (3.94 in) in length:

0.10 mm (0.0039 in)


(A)

Thickness gauge

(B)

Connecting rod



Install the connecting rod fitted with bearing to crankshaft, and then measure the side clearance (thrust clearance). Replace the connecting rod if the side clearance exceeds the specified limit.

Connecting rod side clearance:

Standard

0.070 — 0.330 mm (0.0028 — 0.0130 in)


Inspect the connecting rod bearing for scar, peeling, seizure, melting, wear, etc.

Measure the oil clearance on individual connecting rod bearings by means of plastigauge. If any oil clearance is not within specification, replace the defective bearing with a new one of standard size or undersize as necessary. (See the table below.)

Connecting rod oil clearance:

Standard

0.026 — 0.052 mm (0.0010 — 0.0020 in)

Unit: mm (in)

Bearing

Bearing size

(Thickness at center)

Outer diameter of crank pin

Standard

1.486 — 1.498

(0.0585 — 0.0590)

51.984 — 52.000

(2.0466 — 2.0472)

0.03 (0.0012)

undersize

1.504 — 1.512

(0.0592 — 0.0595)

51.954 — 51.970

(2.0454 — 2.0461)

0.05 (0.0020)

undersize

1.514 — 1.522

(0.0596 — 0.0599)

51.934 — 51.950

(2.0447 — 2.0453)

0.25 (0.0098)

undersize

1.614 — 1.622

(0.0635 — 0.0639)

51.734 — 51.750

(2.0368 — 2.0374)



Inspect the bushing at connecting rod small end, and replace if worn or damaged. Also measure the piston pin clearance at connecting rod small end.

Clearance between piston pin and bushing:

Standard

0 — 0.022 mm (0 — 0.0009 in)



Replacement procedure is as follows:

Remove the bushing from connecting rod with ST and press.

Press the bushing with ST after applying oil on the periphery of bushing.

ST 32005122 CONNECTING ROD BUSHING REMOVER AND INSTALLER


Make two 3 mm (0.12 in) holes in bushing. Ream the inside of bushing.

After the completion of reaming, clean the bushing to remove chips.

CRANKSHAFT AND CRANKSHAFT BEARING

Clean the crankshaft completely and check for cracks by means of red lead check etc., and replace if defective.

Measure the crankshaft bend, and correct or replace if it exceeds the limit.

Note

If a suitable V-block is not available, install the #1 and #5 crankshaft bearing on cylinder block, position the crankshaft on these bearings and measure the crankshaft bend using a dial gauge.


Crankshaft bend limit:

0.035 mm (0.0014 in)


Inspect the crank journal and crank pin for wear. If they are not within the specifications, replace the bearing with a suitable (undersize) one, and then replace or recondition the crankshaft as necessary. When grinding the crank journal or crank pin, finish them to specified dimensions according to the undersize bearing to be used.

Crank pin and crank journal:

Out-of-roundness

0.005 mm (0.0002 in) or less

Taper limit

0.006 mm (0.00024 in)

Crank pin grinding limit (diameter)

51.750 mm (2.0374 in)

Crank journal grinding limit (diameter)

59.750 mm (2.3524 in) or less


Unit: mm (in)

Crank journal diameter

Crank pin diameter

#1, #3, #5

#2, #4

Standard

Journal O.D.

59.992 — 60.008

(2.3619 — 2.3625)

59.992 — 60.008

(2.3619 — 2.3625)

51.984 — 52.000

(2.0466 — 2.0472)

Bearing size

(Thickness at center)

1.998 — 2.011

(0.0787 — 0.0792)

2.000 — 2.013

(0.0787 — 0.0793)

1.486 — 1.498

(0.0585 — 0.0590)

0.03 (0.0012)

undersize

Journal O.D.

59.962 — 59.978

(2.3607 — 2.3613)

59.962 — 59.978

(2.3607 — 2.3613)

51.954 — 51.970

(2.0454 — 2.0461)

Bearing size

(Thickness at center)

2.017 — 2.020

(0.0794 — 0.0795)

2.019 — 2.022

(0.0795 — 0.0796)

1.504 — 1.512

(0.0592 — 0.0595)

0.05 (0.0020)

undersize

Journal O.D.

59.942 — 59.958

(2.3599 — 2.3605)

59.942 — 59.958

(2.3599 — 2.3605)

51.934 — 51.950

(2.0447 — 2.0453)

Bearing size

(Thickness at center)

2.027 — 2.030

(0.0798 — 0.0799)

2.029 — 2.032

(0.0799 — 0.0800)

1.514 — 1.522

(0.0596 — 0.0599)

0.25 (0.0098)

undersize

Journal O.D.

59.742 — 59.758

(2.3520 — 2.3527)

59.742 — 59.758

(2.3520 — 2.3527)

51.734 — 51.750

(2.0368 — 2.0374)

Bearing size

(Thickness at center)

2.127 — 2.130

(0.0837 — 0.0839)

2.129 — 2.132

(0.0838 — 0.0839)

1.614 — 1.622

(0.0635 — 0.0639)



O.D.: Outer Diameter

Measure the thrust clearance of crankshaft at center bearing. If the clearance exceeds the limit, replace the bearing.

Crankshaft thrust clearance:

Standard

0.030 — 0.115 mm (0.0012 — 0.0045 in)


Inspect individual crankshaft bearings for signs of flaking, seizure, melting, and wear.

Measure the oil clearance on each crankshaft bearing by means of plastigauge. If the measurement is not within the specification, replace the defective bearing with an undersize one, and replace or recondition the crankshaft as necessary.

Crankshaft oil clearance:

Standard

0.010 — 0.030 mm (0.0004 — 0.0012 in)