Engines Iveco C10,C13, Cursor 10, Cursor 13. Instruction - page 27

60604

99369

Figure 18

Figure 19

X

. Detail of main journals connections

Y.

Detail of crank pins connections

MAIN DATA FOR THE CRANK SHAFT PINS AND THE HALF BEARINGS

Check the condition of the journals and the big end pins; there must no be signs of scoring,

ovalization or excessive wear. The data given refer to the normal diameter of the pins.

60603

Upper main journal half bearings

Lower main journal half bearings

Figure 20

BUFF

GROUND

GROUND

GROUND

BUFF

108

1.6

R 5

R 3.7 to 4

9t

o

1

2

0.8

±0.3

0.8

±0.3

108

R 5

R 4.2 to 4.5

9t

o

1

2

0.3

0.3

15

CURSOR ENGINES F3A

SECTION 4 - OVERHAUL AND TECHNICAL SPECIFICATIONS

Base - May 2007

MEASURING CRANK PINS

During grinding, pay attention to journal and crank pins values
specified in Figure 19 and Figure 20.

47536

Figure 21

Figure 22

MEASURING THE MAIN JOURNALS

Measuring the main journals and crankpins

Before grinding the crank pins using a micrometer (1),
measure the main journals and the crank pins (2) and decide,
on the basis of the undersizing of the bearings, the final
diameter to which the pins are to be ground.
The undersize classes are 0.127 - 0.254 - 0.508 mm.

It is advisable to enter the values found in a table
(Figure 22).

All journals and crank pins must also be ground to
the same undersizing class, in order to avoid any
alteration to shaft balance.

Figure 23

Fill in this table with the measurements of the main journals and the crank pins.

MAIN JOURNALS

36061

∅ MIN.

∅ MAX.

∅ MIN.

∅ MAX.

CRANK PINS

47535

NOTE

NOTE

16

SECTION 4 - OVERHAUL AND TECHNICAL SPECIFICATIONS

CURSOR ENGINES F3A

Base - May 2007

Preliminary measurement of main and big end bearing shell selection data

For each of the journals of the crankshaft, it is necessary to carry out the following operations:

MAIN JOURNALS:
- Determine the class of diameter of the seat in the

crankcase.

- Determine the class of diameter of the main journal.

- Select the class of the bearing shells to mount.

CRANKPINS:
- Determine the class of diameter of the seat in the

connecting rod.

- Determine the class of diameter of the crankpin.

- Select the class of the bearing shells to mount.

DEFINING THE CLASS OF DIAMETER OF THE SEATS FOR BEARING SHELLS ON THE CRANKCASE

On the front of the crankcase, two sets of numbers are marked in the position shown (Figure 24 at top).

- The first set of digits (four) is the coupling number of the crankcase with its base.

- The following seven digits, taken singly, are the class of diameter of each of the seats referred to (Figure 24 at bottom).

- Each of these digits may be 1, 2 or 3.

47535

99.000 to 99.009

99.010 to 99.019

99.020 to 99.030

Figure 24

CLASS

MAIN BEARING HOUSING

NOMINAL DIAMETER

17

CURSOR ENGINES F3A

SECTION 4 - OVERHAUL AND TECHNICAL SPECIFICATIONS

Base - May 2007

To obtain the required assembly clearances, the main and big end bearing shells need to be selected as described
hereunder.

This operation makes it possible to identify the most suitable bearing shells for each of the journals (the bearing shells, if necessary,
can have different classes from one journal to another).

red

red/black

green

green/black

STD

1.970 to 1.980

1.981 to 1.990

+0.127

2.033 to 2.043

2.044 to 2.053

+0.254

2.097 to 2.107

2.108 to 2.117

+0.508

2.224 to 2.234

2.235 to 2.244

Depending on the thickness, the bearing shells are selected
in classes of tolerance marked by a coloured sign (red-green
— red/black — green/black).

The following tables give the specifications of the main and
big end bearing shells available as spares in the standard sizes
(STD) and in the permissible oversizes (+0.127, +0.254,
+0.508).

* Fitted in production only and not supplied as spares

Figure 25

yellow*

yellow/black*

1.991 to 2.000

red

red/black

green

green/black

STD

2.965 to 2.974

2.975 to 2.984

+0.127

3.028 to 3.037

3.038 to 3.047

+0.254

2.097 to 2.107

2.108 to 2.117

+0.508

2.224 to 2.234

2.235 to 2.244

yellow*

yellow/black*

2.985 to 2.995

2.054 to 2.063

3.048 to 3.058

Selecting the main and big end bearing shells

NOTE

18

SECTION 4 - OVERHAUL AND TECHNICAL SPECIFICATIONS

CURSOR ENGINES F3A

Base - May 2007

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