Dismantling, check and assemblage of the cylinder head

Device

The cylinder head is cast from an aluminum alloy, cast iron has a molded seat and the valve guides. The upper part of the sleeves is sealed by rubber valve stem seals.

As the parts are supplied guides with an increased outer diameter.

In the upper part of the cylinder head positioned under the necks of the support shaft. The supports are made detachable. Stored in the upper half of the bearing housings, and the bottom - the cylinder head. The holes in the supports processed assembled with bearing housings, so they are not interchangeable, and the cylinder head can be replaced only in assembly with the housing.

The valves are actuated by the cams of the camshaft via hydraulic tappets. Adjusting the clearances in the valve mechanism with hydraulic tappets made when the engine automatically.

Dismantling

With a special tool (key bolt cylinder head 09221-32001, 09221-11000), unscrew the cylinder head bolts in the order shown in the diagram (Fig. 2.141).

With a special tool (fixture to compress the valve springs 09222-28000 and 09222-28100 adapter) Remove the crumbs from the plate valve spring. Then remove the plate valve springs, valve spring, spring seat valve and the valve (Fig. 2.142).

With a special tool (extractor valve stem seals 09222-29000), remove the valve stem seals (Fig. 2.143).

Check the cylinder head

Check the cylinder head for cracks, damage and leakage of coolant. If cracks are found, replace the cylinder head.

Thoroughly clean the cylinder head from the scale, sludge and remnants of the old sealant and gaskets. After cleaning the oil passage blow with compressed air to remove any blockage.

Check flatness mating surface of the cylinder head in the directions shown in the figure Fig. 2.144.

If the flatness exceeds the limit in any direction, either replace the cylinder head or lightly abrade the mating surface of the cylinder head.

Nonflatness mating surface of the cylinder head:

- Nominal value - less than 0.03 mm;

- The limit value - 0.06 mm.

Details of the valve mechanism

With a wire brush, thoroughly clean the valve (Fig. 2.145).

Check each valve and its stem for wear, damage and deformation of the plate (Fig. 2.146).

Replace the valve if necessary. If at the end of the valve stem formed dents or present considerable wear, treat the end of the valve stem. The thickness of the release layer in the machining end of the valve stem must be minimal. In addition, process operational facet of the valve seat.

Replace the valve if the valve disc thickness less than the limit.

This thickness of the valve disc are shown below.

Nominal value:

- Inlet valve - 1.15 mm;

- Exhaust valve - 1.35 mm.

Limit:

- Inlet valve - 0.80 mm;

- Exhaust valve - 1.00 mm.

Valve springs

Check the length of each of the valve spring in a free state. If the length of the spring is less than the limit, replace the valve spring (Fig. 2.147).

With check-square deviation of the axis of each spring from the perpendicular to the bearing surface (perpendicularity) (Fig. 2.148).

If perpendicularity over the limit, replace the valve spring.

Valve spring

The nominal value of the length of the spring in a free state: 48.86 mm.

Spring length under a load of 183 N: 39.00 mm.

Spring length under a load of 400 N: 30.50 mm.

Deviation spring axis (perpendicularity): 1.5 ?� or less.

Limit

The length of the spring in a free condition 47,86 mm.

The deviation of the spring axis (perpendicularity) 3 ?�.

Valve guides

Check the gap between the valve guide and valve stem (several points along the length). If the clearance is more than the limit, replace the valve guide (Fig. 2.149).

The values of the gap between the guide sleeve and valve stem are shown below.

Nominal value:

- Inlet valve - 0.02-0.05 mm;

- Exhaust valve - 0,035-0,065 mm.

Limit:

- Inlet valve - 0.10 mm;

- Exhaust valve - 0.13 mm.

Restoration of the valve seat

Check the valve seat for signs of overheating and uneven contact with the working facet of the valve disc. If necessary or restore (machined) or replace the valve seat. Before restoring the valve seat check valve guide for wear. If the guide sleeve is worn, replace it first, and then restore the valve seat. Restoration of the valve seat is made special tool (cutters or machine tools). The width of the contact surface of the valve seat must correspond to the nominal values and the contact patch should be placed evenly in the middle of a working facet of the valve disc. After the restoration of the valve seat and valve seat should be ground using lapping compound.

Replacing the valve seat

Machined (cut away) replaces the valve seat from the inside to reduce the thickness of its walls.

Chisel a hole in the cylinder head for the installation of the valve seat corresponding repair size (larger diameter) (Fig. 2.151).

Heat the cylinder head to a temperature of about 250 ?� C and press in a new saddle repair size location hole in the cylinder head.

Grind to a new valve seat using lapping compound.

The width of the contact surface of the valve seat for the inlet channel - 1.1-1.5 mm for the exhaust passage - 1.3-1.7 mm.

Replacing the valve guide

With a special tool (Tool for fitting the guide sleeve 09221-22000A / B), press out the old valve guide from the cylinder head in the direction of the surface of the gasket (Fig. 2.152).

Ream hole cylinder head for mounting the valve guide of the corresponding repair size (larger diameter).

With a special tool (Tool for fitting the guide sleeve 09221-22000A / B) press in the new valve guide from the upper surface of the cylinder head. Note the difference between the lengths of guides for the intake and exhaust valves (Fig. 2.153).

After installing the valve guide, insert a new valve and check that the gap between the guide sleeve and valve stem corresponds to the nominal value.

After replacing the valve guide, check for correct seating in the valve seat. If necessary, treat the valve seat.

Assembly

Apply engine oil to all rubbing and rotating parts.

Install the valve spring seat.

With a special tool (mandrel to install the valve stem seal 09222-22001) a light blow install the valve stem seal in place (Fig. 2.154).

Lubricate the valve stem with engine oil. Insert the valve into directing plug.

Do not force the passage of the valve stem through the valve stem seal. After installing the valve, check the smoothness of its movement.

Install the valve spring so that the painted coil spring was located near the spring plate (top), and then install the valve spring plate (Fig. 2.155).

With a special tool (fixture to compress the valve springs 09222-28000 and 09222-28100 adapter) compress valve spring and establish crackers. Before removing the special tool after installing the valve check the reliability of the installation of crackers (Fig. 2.156).

Clean the gasket plane of the gasket on the head and the cylinder block.

Check the identification marks cylinder head gasket technical data.

Install the cylinder head gasket on the engine block with an identification mark up (to the cylinder head).

Tighten the cylinder head to the specified torque in the order shown in the diagram in Fig. 2.157.

Tightening torque of bolts fastening the cylinder head:

M10-25 Nm + (60-65 ?�) + (60-65 ?�);

M12-30 Nm + (60-65 ?�) + (60-65 ?�).