In the article, consider the operations on disassembling and repairing the head of the engine cylinders

Disassembling the head of cylinders

Rinse the cylinder head and install on the workbench or disassembly device

Разборка и ремонт головки цилиндров двигателя H4M

Remove the pushers of valves from the cylinder head and label their position relative to the cylinder head

Using the device, squeeze the valve springs and remove crackers with tweezers

Press oil caps with special ticks or inertial puller

 Разборка и ремонт головки цилиндров двигателя H4M

Check the height of the cylinder head

Height H, (drawing) Cylinder heads should be 125 mm

 Разборка и ремонт головки цилиндров двигателя H4M

Using a calibration line and a set of probe, check the flatness of the surface of the cylinder head, marked with the cylinder block

Maximum allowable non-plane of the conjugable surface of the cylinder head 0.1 mm

Check the diameter of the supports for distribution shafts, for this:

Install the cylinder head centering bushings, camshaft bearings caps

Tighten the cover bolts with a torque of 9.0-11.0 nm (0.9-1.1 kgf)

 Разборка и ремонт головки цилиндров двигателя H4M

Nutromer Nor 18-50-1 Measure holes for each cover

The diameter of the holes for the first cover 1 (Figure) must be 28,000-28,021 mm, for openings 2 of the rest of the lids 25,000-25,021 mm

After that, we unscrew the fastening bolts and remove the lids of the camshaft bearings and the centering bushings

Check the diameter of the holes of the valves guide sleeves

The maximum allowable diameter should not be more than 5.03 mm

Check the diameter of the sockets for pushers in the cylinder heads

The diameter of the sockets should be 30,000-30.021 mm

Check the outer diameter of valve pushers

The pusher diameter should be in the range of 29.977-29.987 mm

On the surface of the pushers should not be traces of wear and cracks of the coating

Checking the valve

Unilateral wear of the valve rod on the working surface is not allowed

We visually determine the wear and state of the valve plates.Squirs, cracks and one-sided wear are not allowed

We determine the wear of the end of the valve rod, if necessary, you can pass the end

 Разборка и ремонт головки цилиндров двигателя H4M

Permissible valve dimensions in drawing and according to the table

Valid valve dimensions

Inlet valve:

Diameter of the plate of valve D, mm 31.6 ± 0.15

Valve valve diameter D, mm 4,965 - 4,980

Valve length L, mm 101,48

Height of the cylindrical part of the valve plate T, mm 1.00

Exhaust valve:

Diameter of the plate of valve d, mm 25.3 ± 0.15

Diameter of the valve rod D, mm 4,955 - 4,970

Valve length L, mm 102.24

Height of the cylindrical part of the valve plate T, mm 1.00

Checking the springs of the valves

Spring length in free state - 42.26 mm

Spring length under load 145 ± 9 H (14.5 ± 0.9 kgf) - 34.4 mm

 Разборка и ремонт головки цилиндров двигателя H4M

Deviation "T" (Figure), springs from perpendicularity should not be more than 1.6 mm

Check the valve seat and put the valve

After that, we wash and blow all the holes and parts of the GBC

We collect cylinders head

Install inlet and exhaust valves in the cylinder head

To do this, set the cylinder head to the device 67.7823-9567 for drying and drumming valves

Lubricate motor oil valve rods

We will prescribe with the help of a mandrel 67.7853-9732 Oil reflective caps until it stops in the supporting surface of the cylinder head

Install the cylinder head supporters springs

Install the springs of valves and springs plates

Lubricate the outer surfaces of the pushers with engine oil and set the pushers in the cylinder head according to the labeling

With the help of a spilet, we twist the new studs of fastening the exhaust manifold in the head of the cylinders, a short part into the head body

Remove the cylinder head from the device

Installing the cylinder head

We will be pressed into the cylinder block two centering sleeves of the cylinders head (if they are not installed).Speakers of the sleeve over the capel plane of the cylinder block 6-8 mm

We apply to the surface of the block of cylinders from the drive side of the timing of two points of sealant, as shown in the picture

 Установка головки блока цилиндров H4M

We set a new cylinder head gasket on the cylinder block and put on the gasket from the Timing drive two points of sealant, as shown in the picture

Apply Silicone TB 1217L sealant, flow rate - 1 gram

Twist in the crankshaft bolt fastening crankshaft pulley and install pistons in the middle of the course

We set the cylinder head on the cylinder block, the washers of the cylinder head bolts, new fastening bolts.Twist and tighten the cylinder head mounting bolts

Установка и затяжка ГБЦ

Tightening the cylinder head mounting bolts in the order indicated in the figure in the following sequence (replacement head 11, the knob, extension, the point is torque, the head measurement head):

- tighten the tightening torque bolts 35.0 ... 44.0 N.MM (3.5 ... 4.4 kgf.m);

- Trust bolts at an angle of 60º ... 65º.

- unscrew all the bolts;

- tighten the tightening torque bolts 35.0 ... 44.0 N.MM (3.5 ... 4.4 kgf.m);

- Trust bolts at an angle of 75º ... 80º.