All parts entering the assembly must be cleaned of dirt, carbon deposits and scale, degreased, washed and dried

Oil channels and holes in parts must be cleaned, flushed under pressure and blown with compressed air.

It is not allowed to wash parts made of aluminum and zinc alloys in alkaline solutions used for washing steel and cast iron parts, since aluminum and zinc dissolve in alkalis.

All units, as well as parts of disassembled units during repair, can be depersonalized, with the exception of the following parts:

  • - cylinder block and main bearing caps;
  • - connecting rod and connecting rod caps;
  • - final drive gears;
  • - bearing caps of the differential and final drive housing;
  • - right and left differential pinion boxes. It is allowed to complete the main gear from fit working or new gears, subject to the obligatory check of their engagement on a special device.

Splits on the gear teeth and chipping of the working surface of the teeth are not allowed.

Cylinder block

The cylinder block and main bearing caps should not be dismantled during disassembly, inspection and sorting, as they are processed together and therefore not interchangeable.

Cylinder blocks entering the assembly must be thoroughly cleaned of dirt and scale, and oil channels - from sludge and chips.

Main bearing housings must be bored to nominal size if their size and misalignment exceed the allowable value.

The cleanliness of the bored sockets should correspond to class 6-b according to GOST 2789-51, and their maximum misalignment should not exceed 0.02 mm.

When checking, as well as when boring the nests, the tightening torque of the mounting bolts, main bearing caps should be 11-12 kgm.

Traces of blackness are not allowed on the surface of the bored sockets of the liners.

The camshaft bushings pressed into the cylinder block must be bored to the nominal or one of the repair dimensions given in Table. 1.

The cleanliness of the bored surfaces should correspond to class 7 according to GOST 2789-51, and the misalignment of the bushings should not exceed 0.025 mm.

The misalignment of the axes of the crankshaft and camshafts should not exceed 0.04 mm over the entire length, and the distance between the axes should be within 125.5 ± 0.025 mm.

The deviation from the perpendicularity of the axis of the holes for the cylinder liner to the axis of the crankshaft is allowed within 0.015 mm over a length of 100 mm, and the axis of the holes for the tappets to the axis of the camshaft is no more than 0.050 mm over a length of 100 mm.

To allow for selective assembly in new cylinder blocks, tappet bores are sorted into two size groups.

The size groups are marked with oil-resistant paint on the lugs under the pushers.

After processing the holes for the repair size pushers, they must also be sorted into size groups. The marking of size groups and the repair dimensions of the holes for the pushers are given in Table. 2.

Cylinder liners

Cylinder liners installed on one engine must be of nominal size or bored and honed to one repair size common for all liners indicated in Table. 3.

The ovality and taper of finished cases must not exceed 0.02 mm. Moreover, the larger base of the cone should be at the bottom of the sleeve.

Barrel-shaped and corseted no more than 0.01 mm.

The surface of the sleeve should be mirror-shiny without scratches and blackness, its cleanliness should correspond to class 9-a.

In order to ensure selective assembly of the sleeve-piston interface, nominal-size liners are sorted into five size groups at automotive plants.

Size groups are indicated by the letters of the Russian alphabet, which are printed with a rubber seal on the polished outer surface of the sleeves.

For the same purpose, cases machined to repair size should also be sorted into size groups.

If the ovality of the seating surface of the sleeve exceeds the allowable value of 0.025 mm, then the surface must be restored by remaining, followed by processing to the nominal size.

In this case, the beating of the seating surface relative to the inner surface of the sleeve should not exceed 0.08 mm, and the non-parallelism of the axes of these surfaces should not exceed 0.02 mm over a length of 100 mm.

Tab. 3 Size groups of sleeves nominal and

repair sizes and their designations

Names

Zoom

diameter

shells,

mm

Contact

groups

Diameter

cases, mm

Rated

-

A

92.0+0.012

B

92.0+0.024

In

92.0+0.036

G

92.0+0.048

Д

92.0+0.060

1st repair

0.5

1A

92.5+0.012

1B

92.5+0.024

1B

92.5+0.036

1G

92.5+0.048

1D

92.5+0.060

2nd repair

1.0

2A

93.0+0.012

2B

93.0+0.024

2V

93.0+0.036

2G

93.0+0.048

2D

93.0+0.060

3rd repair

1.5

3A

93.5-0.012

3B

93.5+0.012

3V

93.5+0.024

3G

93.5+0.036

3D

93.5+0.048

Tab. 2 Dimensional groups of holes for pushers

nominal and repair dimensions

Name

Zoom

diameter

holes, mm

group

Color

marking

groups

Diameter

holes,

mm

Rated

-

I

Yellow

25.0+0.011

II

Blue

25.0+0.023

1st repair

0.10

I

White

25.1+0.011

II

Green

25.1+0.023

2nd repair

0.20

I

Black

25.2+0.011

II

Red

25.2+0.023

Tab. 1 Nominal and repair dimensions

holes in camshaft bushings

Name

size

Reduce

diameter, mm

hole diameter

in the sleeve,

mm

Rated

-

50.0+0.05

1st repair

0.25

49.75+0.05

2nd repair

0.5

49.5+0.05

Pistons and piston pins

Tab. 4 Size groups of pistons nominal and

repair sizes and their designations

Name

Zoom

diameter

shells, mm

Designation

groups

Diameter

cases, mm

Rated

-

A

92.0-0.012

B

92.0+0.012

In

92.0+0.024

G

92.0+0.036

Д

92.0+0.048

1st repair

0.5

1A

92.5-0.012

1B

92.5+0.012

1B

92.5+0.024

1G

92.5+0.036

1D

92.5+0.048

2nd repair

1.0

2A

93.0-0.012

2B

93.0+0.012

2V

93.0+0.024

2G

93.0+0.036

2D

93.0+0.048

3rd repair

1.5

3A

93.5-0.012

3B

93.5+0.012

3V

93.5+0.024

3G

93.5+0.036

3D

93.5+0.048

Pistons of nominal and three repair sizes are produced for car repair production.

To ensure selection by sleeves, the pistons are sorted into five size groups, which are indicated by the letters of the Russian alphabet.

The designation of the size group is embossed on the piston crown.

Dimensional groups of pistons of nominal and repair sizes, as well as their designations, are given in Table. 4.

The pistons are sorted into four size groups according to the diameter of the piston pin hole.

The groups are marked with oil-resistant paint on the outer surface of the piston bosses.

Dimensional groups of the hole for the piston pin and their marking are shown in Table 5.

The piston skirt is oval and tapered.

The major axis of the oval is located in a plane perpendicular to the axis of the piston pin, and the taper of the skirt in the same plane should be 0.013-0.038 mm.

The largest diameter of the cone should be at the bottom of the skirt.

When overhauling engines, piston pins of only nominal size are used, which are sorted into four size groups.

Dimensional groups of piston pins of nominal size and their marking are given in table. 6.

Piston rings

Piston rings are produced in nominal and three repair sizes given in table. 7.

Of the three rings installed on one piston, two (the second compression and oil scraper) should be coated with half, and the upper compression with chrome.

When checking in a ring gauge of the appropriate size, no clearance is allowed between the piston ring and the gauge.

The elasticity of compression rings compressed by a steel tape to a gap in the joint of 0.3 ∕0.5 mm should be 1.75 - 2.50 kg, and oil scraper - 1.5 - 2.2 kg.

Cranks

The connecting rod and the connecting rod cover should not be dismantled during disassembly, inspection and sorting, as they are not interchangeable.

It is allowed to restore the hole of the lower head of the connecting rod by leaving it with subsequent processing to the nominal size.

Before machining the bottom head, the connecting rod bolt nuts must be tightened with a torque wrench. Tightening torque - 6.8 - 7.5 kgm.

The bushings pressed into the upper head of the connecting rods must be bored to the nominal size.

Before boring, the sleeves must be ironed with a brooch.

The cleanliness of the machined surfaces in the bushing and the lower head of the connecting rod must comply with class 8-b.

After boring, the ovality and taper of the upper head of the connecting rod should not exceed 0.005 mm, the lower one - 0.008 mm.

The non-parallelism of the axes of the holes of the upper and lower heads of the connecting rod is no more than 0.03 mm over a length of 100 mm, the axes of the holes of the upper and lower heads of the connecting rod must lie in the same plane, the deviation is not more than 0.04 mm over a length of 100 mm.

Tab. 5 Labeling of size groups

piston pin holes

Group

color

marking

diameter

holes, mm

I

White

25.0-0.0025

II

Green

25.0-0.0050

III

Yellow

25.0-0.0050

IV

Red

25.0-0.0075

Tab. 6 Labeling of size groups

nominal size piston pins

Group

color

marking

diameter

piston

finger, mm

I

White

25.0-0.0025

II

Green

25.0-0.0050

III

Yellow

25.0-0.0050

IV

Red

25.0-0.0075 ∕-0.0100

Tab. 7 Nominal and repair dimensions

piston rings

Name

size

Zoom

diameter, mm

Diameter

piston

rings, mm

nominal

-

92.00

1st repair

0.5

92.50

2nd repair

1.0

93.00

3rd repair

1.5

93.50

Tab. 8 Labeling of size groups

holes in the upper head sleeve

connecting rod

Group

Color

marking

Diameter

holes, mm

I

White

25.0+0.0070

+0.0045

II

Green

25.0+0.0045

III

Yellow

25.0+0.0020

—0.0005

IV

Red

25.0-0.0005

—0.0030

The perpendicularity of the end surfaces of the lower head relative to the axis of the hole is no more than 0.05 mm.

For connecting rods entering the engine assembly, the distance between the axes of the lower and upper heads should be 155.95 - 156.05 mm.

In order to be able to selectively assemble the connecting rod with the piston pin, the connecting rods must be sorted into groups according to the hole size in the upper head.

Each group of connecting rods is marked with oil-resistant paint of a certain color. The marking of the connecting rods is given in Table. 8.

Crankshaft

Tab. 9 Nominal and repair dimensions

main and connecting rod journals

crankshaft

Name

size

Reduce

diameter,

mm

diameter

Indigenous

necks, mm

diameter

connecting rod

necks, mm

Rated

-

70.00-0.013

60.00-0.013

1st repair

0.25

69.75-0.020

59.75-0.013

2nd repair

0.50

69.50-0.020

59.50-0.013

3rd repair

0.75

69.25-0.020

59.25-0.013

4th repair

1.00

69.00-0.020

59.00-0.013

5th repair

1.25

68.75-0.020

58.75-0.013

6th repair

1.50

68.50-0.020

58.50-0.013

At crankshafts entering the assembly, oil channels and dirt traps must be thoroughly cleaned of sludge.

Connecting rod and main journals must be nominal or one of the repair sizes indicated in Table. 9.

When grinding the crankpins, the radius of the crank must be kept at nominal.

Different repair sizes are not allowed for necks of the same name.

The ovality and taper of the crankshaft journals must not exceed 0.01 mm.

The cleanliness of the surface of the necks must correspond to the 9th grade.

The length of the front main neck should be in the range of 30.45-30.90 mm. The length of the connecting rod neck is 52.0-52.2 mm.

The radii of the fillets of the connecting rod journals should be within 1.2-2.0 mm, the main ones - 1.2-2.5 mm.

When rotating the shaft installed in the prisms on the extreme main journals, the runout should not exceed:

  • - for medium main journals - 0.02 mm;
  • - for the neck under the timing gear - 0.03 mm;
  • -> fan pulley hub - 0.04 mm;
  • -> > rear oil seal - 0.04mm;
  • - flange at the end - 0.04 mm.

The non-parallelism of the axes of the connecting rod and main journals is no more than 0.012 mm along the length of each journal.

Main and connecting rod bearings

Tab. 10 Nominal and repair dimensions

main and connecting rod bearings

bearings

size

Reduce

internal

diameter

insert,

mm

Thickness of liners, mm

Indigenous

bearings

Conrod

bearings

nominal

2.250-0.013

1.750-0.013

1st repair

0.25

2.375-0.013

1.875-0.015

2nd repair

0.50

2.500-0.013

2,000-0.015

3rd repair

0.75

2.625-0.013

2.125-0.015

4th repair

1.00

2.750-0.013

2.250-0.015

5th repair

1.25

2.875-0.013

2.375-0.015

6th repair

1.50

3,000-0.013

2.500-0.015

Thin-walled crankshaft bearing shells must be completely interchangeable, and provide, without selection, the fit in the bearing mates necessary for the normal operation of the engine.

Cracks and chipping of the anti-friction layer from the steel tape at the connecting rod and main bearings are not allowed.

Nicks and scratches on the work surface are not allowed.

On the reverse side of the insert, no more than three scratches are allowed with a depth of no more than 0.1 mm.

Sharp edges and burrs at the liner joints must be cleaned.

Nicks, scratches and corrosion on the planes of the joints of the liners are not allowed. Cleaning the joints to remove these defects is not allowed.

The locking lug of the liner must not be damaged.

Repair of liners by refilling the antifriction layer is not allowed.

The nominal and repair dimensions of the liners are given in Table. 10.

Flywheel

The working surface of the flywheel must be smooth, its cleanliness after processing must correspond to the 9th grade.

The flywheel must be statically balanced. The value of the allowable imbalance should not exceed 35 gcm.

When balancing, drill a hole with a diameter of 11 mm at a radius of 156 mm to a depth of 18 mm.

The maximum runout of the working surface should not exceed 0.1 mm.

The dimensions of the holes for the flywheel mounting bolts must not exceed 12.30 mm.

Camshaft

The camshaft bearing journals must be nominal or one of the repair dimensions given in Table. 11.

Ovality and taper of bearing journals - no more than 0.010 mm, Mutual runout of bearing journals and pinion journals - no more than 0.020 mm.

The runout of the cylindrical part of the cams relative to the necks is no more than 0.05 mm.

The surface finish of the support necks must comply with class 9-b.

When installing the shaft on the extreme support journals, the runout of the intermediate journals should not exceed 0.05 mm.

Pushers

The outer diameter of the pushers must be nominal or one of the repair sizes given in Table. 12.

Ovality, taper and faceting of the outer surface of the pusher - no more than 0.007 mm.

The hardness of the outer spherical surface is RC - 60.

On the surface of the pusher, cracks, risks, black spots are not allowed, and whenburns.

Cylinder head

The cylinder head entering the assembly must be thoroughly washed, the cooling jacket must be cleaned of scale and dirt, the oil channels must be free of sludge, and the exhaust channels must be free of carbon deposits.

The valve guides pressed into the head of the block must be nominal or one of the repair sizes and marked with paint.

The dimensions of the bushings and their marking are shown in Table. 13.

The distance from the upper end of the guide bush to the plane of the head should be 24 mm.

Intake and exhaust valve seats must be ground at 45° to the axis of the guide bushings.

The width of the seat bevel should be 1.5 ± 2.0 mm.

The runout of the conical surfaces of all valve seats relative to the axes of the holes in the valve guide bushings is no more than 0.025 mm.

The outer diameter of the valve guides pressed into the cylinder head can be of a nominal size or a repair one (increased by 0.25 mm).

Inlet and outlet valves

The diameters of the valve stems must be nominal or one of the repair sizes given in Table. 14.

The working chamfer of the valve head must be ground at an angle of 45° to the stem axis.

The cleanliness of the working surface of the chamfer after grinding must correspond to the 8th grade.

Beating of the working surface of the chamfer relative to the valve stem is not more than 0.03 mm.

Inlet pipe

At the inlet pipe entering the assembly, the cooling jacket must be cleaned of dirt and scale, and the inlet channels from carbon deposits.

The surfaces of the connector with the cylinder heads must be flat - the deviation is within 0.1 mm no more.

The pipe must be tested with water at a pressure of 3 - 4 kg/cm2.

Tab. 11 Nominal and repair dimensions

support necks

Camshaft

size

Reduce

diameter, mm

Diameter

reference

necks, mm

Rated

50.00-0.017

1st repair

0.25

49.75-0.017

2nd repair

0.50

49.50-0.017

Tab. 12 Nominal and repair dimensions of the pusher

size

Zoom

diameter

pusher,

mm

Group

Color

marking

Diameter

pusher,

mm

Denomination

I

Yellow

25.0-0.015

II

Blue

25.0-0.008

1st repair

0.10

I

White

25.1-0.015

II

Green

25.1-0.008

2nd repair

0.20

I

Black

25.2-0.015

II

Red

25.2-0.008

Tab. 13 Nominal and repair dimensions

valve guide

Size

Zoom

or

reduce

diameter,

mm

marking

Internal

diameter

guide

Valve sleeves, mm

Rated

yellow

9.00+0.022

1st repair

-0.20

White

8.80+0.022

2nd repair

+0.20

Green

9.20+0.022

Tab. 14 Nominal and repair dimensions of valve stems

size

Magnify or

reduce

diameter,

mm

marking

Rod diameter,

mm

Intake

prom

Rated

Yellow

9.0-0.050

9.0-0.075

1st repair

-0.20

White

8.8-0.050

8.8-0.075

2nd repair

+0.20

Green

9.2-0.050

9.2-0.075