Check/face-grind cylinder head contact surfaces

AR01.30-B-7162DD

Check/face-grind cylinder head contact surfaces

06.02.2020

Engine

906.999

Engine

924.92

Engine

926.942 in model 382.171/176

Engine

926.95

1

Intake valve

2

Exhaust valve

3

Constant throttle

4

Dial indicator

5

Gauge holder

B

Valve indentation

C

Difference between the stem end projection of both intake valves

H

Cylinder head height



Remove

1

Remove the head

.

AR01.30-B-5800DD

2

Removing the injection nozzle carrier combination

.

AR07.03-B-6831DD

3

Remove the intake valves (1), and the exhaust valves (2)

.

AR05.30-B-3511DD

4

Remove the constant throttle valve (3)

.

AR01.50-B-1000DD

Inspect

5

Measure the cylinder head total height (H) and the parallelism deviation between the top and bottom faces again

 If the cylinder head total height is smaller than the admissible one, replace the cylinder head.

.Cylinder head height

*BE01.30-B-1001-02C

6

Check the flatness of the cylinder head contact face (combustion chamber side)

.Maximum permissible flatness deviation of cylinder head mating surface

*BE01.30-B-1002-02C

Machining

7

Resurface the cylinder head sealing face (combustion side)

 The rugosity Rz of the cylinder head sealing face must be kept within the specifications.

 Grind the cylinder head sealing surface only in the case of a no-admissible flatness deviation on longitudinal direction, or if there are porous or damaged points. By grinding, do not reduce the cylinder head height (H) below the minimum admissible height.

.Roughness on cylinder head mating surface

*BE01.30-B-1003-02C

.Maximum permissible flatness deviation of cylinder head mating surface

*BE01.30-B-1002-02C

8

Clean the cylinder head



Measure

9

Measure the cylinder head height (H) and the parallelism deviation between the top and bottom faces again

.Cylinder head height

*BE01.30-B-1001-02C

10

Insert the intake valves (1) and the exhaust valve (2) in the cylinder head

 Observe the identification marks of the intake valves (1) and exhaust valves (2).

11

Measure the valve head indentation (B) on the cylinder head, and the admissible difference (C) of the stem projection of both intake valves

Measure valve setback to cylinder head
.

AR05.30-B-4100-01DD

 Measure the indentation (B) of both intake valves (1) and exhaust valve (2), and write down the measured value.

 The difference between the stem end projection of the intake valves (C) may not be exceeded.



Distance between valve face and the cylinder head

*BE05.30-B-1001-01D

Hardness of the valve stem tip

*BE05.30-B-1014-01D

 Dial gage

*001589532100

 Dial indicator holder

*343589004000

 Dial indicator holder

*363589022100

If the obtained measurements are not within the permissible tolerance:



Machine valve seat rings
.

AR05.30-B-4511DD



Install

12

Install the constant throttle valve (3)

.

AR01.50-B-1000DD

13

Install the intake valves (1), and the exhaust valves (2)

.

AR05.30-B-3511DD

 Observe the identification marks of the intake valves (1) and exhaust valves (2).

14

Install the nozzle holder combination

.

AR07.03-B-6831DD

15

Install the cylinder head

.

AR01.30-B-5800DD

Test values for the head

Number

Designation

Engine 904.9/906.9

Engine 926.9

BE01.30-B-1001-02C

Cylinder head height

standard

mm

107,9...108,1

107,9...108,1

minimum after machining

mm

106,9

106,9

Test values for the head

Number

Designation

Engine 924.9

BE01.30-B-1001-02C

Cylinder head height

standard

mm

107,9...108,1

minimum after machining

mm

106,9

Test values for the head

Number

Designation

Engine 904.9/906.9

Engine 926.9

BE01.30-B-1002-02C

Maximum permissible flatness deviation of cylinder head mating surface

on overall length

mm

0,05

0,07

over a length of 150mm

mm

0,02

0,02

Test values for the head

Number

Designation

Engine 924.9

BE01.30-B-1002-02C

Maximum permissible flatness deviation of cylinder head mating surface

on overall length

mm

0,05

over a length of 150mm

mm

0,02

Test values for the head

Number

Designation

Engine 904.9/906.9

Engine 926.9

BE01.30-B-1003-02C

Roughness on cylinder head mating surface

Rz

mm

0,008...0,016

0,008...0,016

R3z

mm

-

-

Test values for the head

Number

Designation

Engine 924.9

BE01.30-B-1003-02C

Roughness on cylinder head mating surface

Rz

mm

0,008...0,016

R3z

mm

-

Test value for the valves

Number

Designation

Engine 902.9,
Engine 906.9 from 415752

Engines 924.9, 926.9

BE05.30-B-1001-01D

Distance between valve face and the cylinder head

intake

Normal

mm

1,1...1,5

1,1...1,5

Maximum repair stage

mm

1,7

1,7

exhaust

Normal

mm

1,1...1,5

1,1...1,5

Maximum repair stage

mm

2,0

2,0

Test value for the valves

Number

Designation

Engine 902.9,
Engine 906.9 from 415752

Engines 924.9, 926.9

BE05.30-B-1014-01D

Hardness of the valve stem tip

intake

HRC

54...60

54...60

Exhaust

HRC

54...60

54...60