Boring and honing cylinder bores

AR01.40-B-9291B

Boring and honing cylinder bores

18.02.2020

Engine

904 in model 368.004/006/112/115/117/185/187, 384.067/201/223, 688.277

Engine

904.924 in model 688.276

Engine

904.957 in model 688.276

Engine

906 in model 368.054/100/154, 382.123/175/184/185/186/188/189

1

Engine block

2

Cylinder liner

a

Chamfer (to facilitate the later piston installation)

1

Secure the engine block (1) in the boring machine

2

Center the cylinder liner (2) to be machined, in relation to the boring machine

 In the case of machining one or more cylinders, observe the work sequence to avoid damages due to excessive heating: 4-cylinders engines; 2-4-1-3, and 6-cylinders engines; 1-3-5-2-4-6.

3

Adjust the tool and carry out the machining, in several steps, until obtaining a diameter 0.05 mm smaller than the final diameter

 Boring machine setting values:
Rotation; 250 - 280/min (rpm)
Feed rate of the tool; 0.04 - 0.06 mm/turn.

Cylinder's internal diameter, finishing

*BE01.40-B-1001-02C

4

Machining the chamfer (a) on the top corner of the liner (2)

 To facilitate the later piston installation.

Chamfer (a) at the upper corner of the cylinder or cylinder liner

*BE01.40-B-1021-02C

5

Hone the cylinder liner (2) until obtaining the desired diameter (final finish)

 Honing machine setting values:
Work pressure; 2.5 - 3.0 bar.
Rotation; 60 - 100/min (rpm).
Honing angle; 40°- 60°
Double stroke; 30 - 40 / min.

Cylinder's internal diameter, finishing

*BE01.40-B-1001-02C

Out of round and taper in the cylinder/deviation from the cylinder's travel (with liner and without liner)

*BE01.40-B-1002-02C

Roughness on the cylinder surface (with liner, without liner)

*BE01.40-B-1020-02C

6

Check for eventual deformation in adjacent cylinders. If necessary hone

 The cylinder(s) adjacent to lined cylinder(s), may suffer deformation due to the pressing-in of the cylinder liner in the engine block.

 Procedure required only when cylinder lining is not carried out in all cylinders.

Cylinder's internal diameter, finishing

*BE01.40-B-1001-02C

Out of round and taper in the cylinder/deviation from the cylinder's travel (with liner and without liner)

*BE01.40-B-1002-02C

Engine block test values

Number

Designation

Engine 904.9, 906.9

BE01.40-B-1001-02C

Cylinder's internal diameter, finishing

Normal

Tolerance A

mm

101,985...101,991

Tolerance B

mm

101,992...102,008

Tolerance C

mm

102,009...102,015

Repair I

Tolerance A

mm

102,285...102,291

Tolerance B

mm

102,292...102,308

Tolerance C

mm

102,309...102,315

Repair II

Tolerance A

mm

102,585...102,591

Tolerance B

mm

102,592...102,608

Tolerance C

mm

102,609...102,615

Repair III

Tolerance A

mm

102,885...102,891

Tolerance B

mm

102,892...102,908

Tolerance C

mm

102,909...102,915

Engine block test values

Number

Designation

Engine 904.9, 906.9

BE01.40-B-1002-02C

Out of round and taper in the cylinder/deviation from the cylinder's travel (with liner and without liner)

contact surface

mm

0,012

Engine block test values

Number

Designation

Engine 904.9, 906.9

BE01.40-B-1020-02C

Roughness on the cylinder surface (with liner, without liner)

R3z

mm

0,003...0,005

Engine block test values

Number

Designation

Engine 904.9, 906.9

BE01.40-B-1021-02C

Chamfer (a) at the upper corner of the cylinder or cylinder liner

a1

mm

0,3...0,4

a2

graus

30