Opel Frontera UBS. Manual - part 384

 

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Opel Frontera UBS. Manual - part 384

 

 

ENGINE MECHANICAL 6A – 9

1. Valve Guide Clearance

Measure the valve stem diameter with a
micrometer.
If the valve stem diameter is less than the specified
limit, the valve and the valve guide must be
replaced as a set.

Measure the inside diameter of the valve guide with
a micrometer.

• Subtract the measured outer diameter of the valve

stem from the measured inner diameter of the
valve guide.  If the valve exceeds of the valve guide.
If the valve exceeds the specified limit, the valve
and the valve guide must be replaced as a set.

Diameter of
Valve stem

Inlet

mm(in)

7.880
(0.3102)

Standard

Limit

Exhaust

7.946 – 7.961
(0.3128 – 0.3134)

7.850
(0.3091)

7.921 – 7.936
(0.3118 – 0.3124)

Inlet clearance

mm(in)

0.200
(0.0079)

Standard

Limit

Exhaust clearance

0.039 – 0.071
(0.0015 – 0.0028)

0.250
(0.0098)

0.064 – 0.096
(0.0025 – 0.0038)

6A – 10 ENGINE MECHANICAL

Valve Guide Replacement

1.

Using special tool, drive out the valve guide from the
combustion chamber side.

Valve guide replacer: 9-8523-1212-0

2.

Apply engine oil to the outside of the valve guide.
Using special tool, drive in a new valve guide from
cylinder head upper face side, and check the valve
guide height.

Valve guide replacer: 9-8523-1212-0

NOTE:

If the valve guide has been removed, both the valve
and the valve guide must be replaced as a set.

Valve Thickness

1.

Measure the valve thickness.

2.

If the measured value is less than the specified limit,
the valve and the valve guide must be replaced as a
set.

Contact surface angle on valve seat on valve

1.

Measure contact surface angle on valve seat.

2.

If the measured value exceeds the limit, replace valve,
valve guide and valve seat as a set.

mm(in)

13 (0.5118)

Height

Standard

mm(in)

Limit

1.1 (0.0433)

1.6 (0.0630)

Valve Depression

Degree

45

Standard

Valve Depression

1.

Install the valve ➀ to the cylinder head ➁.

2.

Use a depth gauge or a straight edge with steel rule to
measure the valve depression from the cylinder head
lower surface.
If the measured value exceeds the specified limit, the
valve seat insert must be replaced.

Inlet

mm(in)

1.1 (0.0433)

Standard

Limit

Exhaust

1.34 (0.0528)

1.1 (0.0433)

1.38 (0.0543)

ENGINE MECHANICAL 6A – 11

Valve Contact Width

1.

Check the valve contact faces for roughness and
unevenness.  Make smooth the valve contact sur-
faces.

2.

Measure the valve contact width.
If the measured value exceeds the specified limit, the
valve seat insert must be replaced.

Valve Seat Insert Replacement

Valve Seat Insert Removal

1.

Arc weld the entire inside circumference  ➀   of the
valve seat insert  ➁.

2.

Allow the valve seat insert to cool for a few minutes.
This will invite contraction and make removal of the
valve seat insert easier.

3.

Use a screwdriver ➂  to pry the valve seat insert free.
Take care not to damage the cylinder head 

  .

4.

Carefully remove carbon and other foreign material
from the cylinder head insert bore.

Valve Seat Insert Installation

1.

Carefully place the attachment ➀  (having a smaller
outside diameter than the valve seat insert) on the
valve seat insert ➁  .

Note:

The smooth side of the attachment must contact
the valve seat insert.

2. Use a bench press ➂ to gradually apply pressure to

the attachment and press the valve seat insert into
place.

Note:

Do not apply an excessive amount of pressure with
the bench press.  Damage to the valve seat insert
will result.

Valve Seat Insert Correction

1. Remove the carbon from the valve seat insert surface.

2. Use a valve cutter (15

°

, 45

°

, and 75

°

 blades) to mini-

mize scratches and other rough areas.  this will bring
the contact width back to the standard value.

Remove only the scratches and rough areas.  Do not
cut away too much.  Take care not to cut away un-
blemished areas of the valve seat surface.

Inlet

mm(in)

2.2 (0.0866)

Standard

Limit

Exhaust

1.7 (0.0669)

2.5 (0.0984)

2.0 (0.0787)

6A – 12 ENGINE MECHANICAL

3.

Visually inspect both ends of the push rod for exces-
sive wear and damage.  The push rod must be re-
placed if these conditions are discovered during
inspection.

REASSEMBLY

6.

Valve Guide

Apply engine oil to the outside of the valve guide.

Using special tool, drive in a new valve guide from
the cmashft side.

Valve guide replacer: 9-8523-1212-0

5.

Valve Stem Oil Seal

Using special tool, drive in a new oil seal

Oil special tool, drive in anew oil seal

Oil seal installer: 5-8840-2033-0

4.

Valve

Apply engine oil to the outside of the valve stem.

Push Rod Curvature

1.

Lay the push rod on a surface plate.

2.

Roll the push rod along the surface plate and measure
the push rod cuvature with a thickness gauge.

If the mesure value exceeds the specified limit, the
push rod must be replaced.

NOTE:

Use an adjustable valve cutter pilot.
Do not allow the valve cutter pilot to wobble inside the
valve guide.

3.

Apply abrasive compound to the valve seat insert
surface.

4.

Insert the valve into the valve guide.

5.

Turn the valve while tapping it to fit the valve seat
insert.

6.

Check that the valve contract width is correct.

7.

Check that the valve seat insert surface is in contact
with the entire circumference of the valve.

mm(in)

0.3 (0.0118)

Push Rod Curvature Limit

degree

45

Valve Seat Angle

 

 

 

 

 

 

 

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