Daewoo Nubira. Manual - part 154

1C – 74

I

DOHC ENGINE MECHANICAL

DAEWOO V–121 BL4

Valve Seat – Cut
1.  Place the cylinder head on wooden blocks.
2.  Cut the intake and the exhaust valve seats using

the guide drift KM–340–7 as follows:

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  Valve seat – A 45–degree surface using the cut-

ter KM–340–13.

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  Upper correction angle – A 30–degree surface

using the cutter KM–340–13.

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  Lower correction angle – A 60–degree surface

using the cutter KM–340–26.

3.  Clean the chippings from the cylinder head.
4.  Inspect the dimension for the valve seat width.

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  Intake: 1.2 to 1.4 mm (0.047 to 0.055 inch).

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  Exhaust: 1.4 to 1.8 mm (0.055 to 0.070 inch).

5.  Inspect the assembly height of the intake valves

and the exhaust valves. If the dimension is exceed-
ed, install new valves. Inspect the assembly height
of the intake valves and the exhaust valves again. If
the valve assembly height is still too large despite
replacing the valves, replace the cylinder head.

Assembly Procedure

1.  Coat the valve stems with engine oil.
2.  Insert the valves in the cylinder head in their origi-

nal positions.

3.  Insert the valve spring seats.
4.  Push the accompanying assembly sleeve onto the

valve stem.

5.  Insert the new valve stem seat.
6.  Carefully drive the valve stem seal onto the stop

with light taps.

7.  Install the valve springs in their original positions.
8.  Install the valve spring caps.

DOHC ENGINE MECHANICAL  1C – 75

DAEWOO V–121 BL4

9.  Compress the valve springs with the valve spring

compressor KM–348 and adapter KM–653.

10.  Install the valve retainers.
11.  Remove the valve spring compressor KM–348 and

adapter KM–653.

12.  Lubricate the valve lash adjusters with engine oil.
13.  Install the valve lash adjusters.

14.  Install the intake camshaft.
15.  Install the intake camshaft bearing caps in their

original positions.

16.  Install the exhaust camshaft.
17.  Install the exhaust camshaft bearing caps in their

original positions.

18.  Install the camshaft bearing cap bolts.
19.  Tighten the camshaft bearing cap bolts gradually

and in the sequence shown for each camshaft cap.

Tighten

Tighten the camshaft bearing cap bolts to 8 N

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m (71

lb–in).

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DOHC ENGINE MECHANICAL

DAEWOO V–121 BL4

20.  Install the spark plugs.

Tighten

Tighten the spark plugs to 20 N

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m (15 lb–ft).

21.  Install the EI system ignition coil and EGR mount-

ing bracket.

22.  Install the EI system ignition coil and EGR mount-

ing bracket bolts.

Tighten

Tighten the EI system ignition coil and EGR mounting
bracket bolts to 25 N

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m (18 lb–ft).

23.  Install the intake manifold studs.
24.  Install the intake manifold gasket.
25.  Install the intake manifold.
26.  Install the intake manifold retaining nuts and retain-

ing bolt in the sequence shown.

Tighten

Tighten the intake manifold retaining nuts and retain-
ing bolt to 22 N

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m (16 lb–ft).

27.  Install the fuel rail assembly. Refer to Section 1F,

Engine Controls.

28.  Install the thermostat housing assembly.
29.  Install the thermostat housing mounting bolts.

Tighten

Tighten the thermostat housing mounting bolts to 15
N

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m (11 lb–ft).

30.  Install the coolant bypass housing and mounting

bolts.

Tighten

Tighten the coolant bypass housing and mounting
bolts to 15 N

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m (11 lb–ft).

31.  Install the camshaft position sensor.

Tighten

Tighten the camshaft position sensor bolts to 12 N

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m

(106 lb–in).

DOHC ENGINE MECHANICAL  1C – 77

DAEWOO V–121 BL4

32.  Install the exhaust manifold studs.
33.  Install the exhaust manifold gasket.
34.  Install the exhaust manifold.
35.  Install the exhaust manifold retaining nuts in the

sequence shown.

Tighten

Tighten the exhaust manifold retaining nuts to 15 N

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m

(11 lb–ft).

36.  Install the exhaust manifold heat shield.
37.  Install the exhaust manifold heat shield bolts.

Tighten

Tighten the exhaust manifold heat shield bolts to 8
N

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m (71 lb–in).

38.  Install the cylinder head with the intake manifold

and the exhaust manifold attached. Refer to ”Cylin-
der Head and Gasket” in this section.

CRANKSHAFT

Tools Required
KM–412 Engine Overhaul Stand
KM–470–B Angular Torque Gauge
KM–635 or J–36972 Crankshaft Rear Oil Seal Installer

Notice : Take extreme care to prevent any scratches,
nicks, or damage to the camshafts.

Disassembly Procedure

1.  Remove the engine. Refer to ”Engine” in this sec-

tion.

2.  Remove the flywheel or flexible plate bolts.
3.  Remove the flywheel or the flexible plate.

4.  Remove the crankshaft rear oil seal.
5.  Mount the engine assembly on the engine overhaul

stand KM–412.