Anglo Eastern Ship Management (Singapore) Pte Ltd

AE OVERHAUL PROCEDURE AND CHECKLIST

AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

VESSEL NAME-

ENGINE MODEL - HYUNDAI HiMSEN 5H 21/32

AUXILIARY ENGINE OVERHAUL

Preface: Performance of any engine varied in accordance with the operating condition & the engine
condition. The most reliable method for a better service & maintenance for any machinery is to record the
data of the engine performance as frequently as possible. A continuous trend analysis of the recorded
data with reference to the engine maker’s shop test results & commissioning data will contribute to
diagnose the condition of the engine precisely & precautions or the preferences can be made in advance.

Before any maintenance is planned, the following steps need to be followed as a thumb rule:

A) Plan well in advance for the upcoming maintenance so that all spares are available on board for
the job concerned.

B) Office permission need to be obtained with the time line for the planned maintenance clearly
defined.

C) Training sessions need to be carried out not once but repeatedly with all concerned personnel &
every minute details will be required to be discussed. This table top exercise will help gain
confidence, be aware of all the data, precisions, torque requirement etc & preparations required
can be taken care off in advance.

D) Risk Assessment is another aspect & each pre maintenance sessions will help identifying the
hazards involved in the job & the mitigating measures required.

The usual & frequent auxiliary engine overhaul involves following maintenances:

1) Cylinder head de carbonization

2) Piston and piston ring overhaul
3) Cylinder liner calibration & Honing
4) Bottom end bearings inspection & renewal
5) T/C Overhaul
6) Fuel Pump Overhaul

Major Overhaul Interval

COMPONENT OVERHAUL INTERVAL

CYLINDER HEAD 8000
PISTON OVERHAUL 16000
LINER CALIBRATION 16000

1
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

TURBOCHARGER OVERHAUL 6000

TURBOCHARGER BEARING RENEWAL 25000
FUEL PUMP COMPLETE OVERHAUL 8000
FUEL VALVE OVERHAUL 2000
AIR COOLER CLEANING 4000

Major Bearings Check

MAIN BEARING (CHECK 1 SET, IF NOT 8000

GOOD, CHECK ALL)
CON ROD BIG END BEARING (CHECK 1 SET, 8000
IF NOT GOOD, CHECK ALL)
CON ROD SMALL END BEARING (CHECK 1 8000
SET, IF NOT GOOD, CHECK ALL)
CAMSHAFT BEARING (CLEARANCE CHECK) 16000

Major Fasteners

NUTS FOR CYLINDER HEAD 8000

NUTS FOR PISTON CROWN 16000
NUTS FOR CON ROD SHAFT 8000
NUT FOR CON ROD BIG END 8000
NUTS FOR COUNTER WEIGHT 8000
NUTS FOR MAIN BEARING CAP 8000
RESILIENT MOUNTING 8000

Critical Operations to be Performed under Chief Engineers Direct Supervision-

Following important operations that are performed during overhaul will be under Chief Engineer’s
presence and guidance-

 Use of hydraulic tools while disassembly/assembly of components

 Disassembly/Assembly & calibration of Piston
 Disassembly/Assembly & calibration of Liner
 Disassembly/assembly of cylinder head suction/exhaust valves and valve guide bore
measurement.
 Bottom end bearing disassembly/assembly
 Valve yoke zero clearance
 Tappet clearance
 Disassembly/Assembly & calibration of Turbocharger

2
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

Cylinder head decarb.-

Following procedures to be followed:

Checklist for securing the engine:

Procedures Check

Engine locked locally and from MSB

Y N
Engine on D.O.
Y N
Starting air v/v shut
Y N
Turning gear engaged
Y N
FO In/Out v/v shut
Y N
L.O priming pump stopped
Y N
Indicator cocks open
Y N
CFW In/Out v/v shut
Y N
Expansion tank vent v/v closed
Y N
Cooling water drained
Y N
Hydraulic tools checked
Y N
Lifting Tools load tested
Y N
Personal Protective Equipment used
Y N
FO sufficient ROB
Y N

Note: The job should not be started unless all the checks boxes are ticked Y Y

3
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

Hydraulic tools:

Correct tools as per maker to be used for opening and tightening cylinder head bolts, Piston Crown bolts,
Con Rod palm bolts, big end bearing bolts & Main bearing bolts.

It is imperative that correct opening/closing pressure to be applied as recommended by maker.

Note 1: Hydraulic Pressure for Untightening is normally +20 bar (max. 5%) abobe the hydraulic oil
pressure for tightening.

For example: Tightening pressure: 1050 bar

Untightening pressure: 1070 (1050 + 20) – Normal

1103 (1050 X 1.05) – Maximum

+ Molycote: Lubricating paste up to 400 o C (Ex GLEITMO 100) (Co efficient Friction: 0.12)

Note 2: Stud length after tightening (H)

PART NAME Pre tightening Hydraulic Hydraulic Stud Length

for Stud (Nm) Tightening for Untightening for after
Nut (bar) Nut (bar) tightening
(mm)
Cylinder head 50 + Locktite 1100 1100 + 20 bar
bolts 243 (max 5%)

Piston Crown 50 + Molycote 1150 1150 + 20 bar

studs (max 5%)
Piston con rod 50 + Molycote 1150 1150 + 20 bar
palm bolts (max 5%)
Big end bearing 50 + Molycote 950 950 + 20 bar
bolts (max 5%)
Stud for Main 50 + Locktite 1200 1200 + 20 bar
Bearing Cap 243 (max 5%)
Stud for Counter 850
Weights

Hydraulic Jack Tightening Procedure

1) Check pre-tightening of the stud and tighten by wrench, if loosened.

2) Clean studs, nuts and around seats.
3) Screw the nut manually until the nut contacting the seat closely.
4) Check condition of the hydraulic tool set and make them ready to use.
5) Mount support (extension screw) and screw the jack by hand.

4
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

6) Connect hoses from the pump to the jacks via the distributing piece.
7) Close the release valve of the hydraulic pump.
8) Open air venting plug of the jack and check air venting by pumping.
9) Close the venting plug and pressurize up to the specified pressure for tightening the nut.
10) Turn the nut to be screwed firmly by a pin manually through the hole of the support.
11) Release the hydraulic pressure by opening the release valve of the hydraulic pump.
12) Repeat pressurizing and check the nut loosened.
13) Retighten the nut, if loosened.
14) If the stud or nut has been replaced by new ones, repeat the tightening three times for the first
tightening. This repeat is necessary for
the settlement of the threads.
15) Release the hydraulic pressure and dismount the tool set.

Hydraulic Jack Loosening Procedure

1) Clean seat and threads.

2) Check condition of the hydraulic tool set and make them ready to use.
3) Mount support (extension screw) and jack.
4) Connect hoses from the pump to the jacks via the distributing piece.
5) Turn the piston of jack until contacting the nut and then unscrew the piston by about half
turn. This is important to provide space for loosening
the nut.
6) Close the release valve of the hydraulic pump.
7) Open air venting plug of the jack and check air venting by pumping.
8) Close the venting plug and pressurize up to the specified pressure for loosening the nut.
9) Unscrew the nut by half turn manually by means of a pin through the hole of the support.
10) Be sure to check that loosened nut moves freely without contacting the piston of the jack.
Otherwise, jack and the nut may be stuck each other after releasing hydraulic pressure. If
stuck, increase hydraulic pressure slightly and turn the nut about 1/4 turn clockwise for loosening
from the piston of the jack.
11) Release the hydraulic pressure and dismount the tool set.

5
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

Note: Pressure gauge of hydraulic pump to be calibrated prior using. We have had cases where
the pressure gauge readings were wrong and thus nuts were over tightened

PHOTOGRAPH OF PRESSURE CALIBRATION:

6
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

CLEARENCES AND LIMITS FOR GENERATOR TO BE CHECKED

CYLINDER LINER

PART Nominal Size Clearance Wear &Repair limit Observed readings

Inner Diameter of D=210+ 0.046 210.4
Cylinder Liner 0

Wall thickness and Max= 4.98 4.75

flame ring Min = 4.93
Cylinder Wall A = 13
thickness B = 69

Piston Ring & Groove

PART Nominal Size Clearance Wear &Repair limit Observed readings

0.50
1st ring A= 6 -0.01 a =0.13 ~ 0.175
-0.025

1st groove A1 = 6 +0.15 6.35

+0.12

2nd ring B = 4.98 -0.01 b = 0.1 ~ 0.145 0.50

-0.025

2nd groove B1 = 5 +0.12 5.35

+0.09

Oil Scrapper ring C=5 -0.01 C = 0.05 ~ 0.085 0.3

-0.025

3rd groove C1 = 6 +0.06 6.20

+0.04

7
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

Piston Pin

PART Nominal Size Clearance Wear &Repair Observed readings

limit
Piston Pin &
a=0.050 ~ 0.085
Boss 0.12
A = 100
Piston pin
b =0.080 ~ 0.149
&Bush 0.25

Big End Bearing

Wear &Repair limit

PART Nominal Size Clearance Observed readings
(shell thickness)
0.3 (Shell
Big end bearing A = 190 a = 0.133 ~ 0.231
thickness 4.925)
0.3 (Shell
Main Bearing B = 220 b = 0.187 ~ 0.285
thickness 4.88)
0.6 (Shell
Thrust Bearing C = 179 c = 0.3 ~ 0.6
thickness 9.80)

VALVE OPERATING MECHANISM AND TAPPET

Part Name Nominal size Clearance as per maker Observed readings

Suction/Exhaust rocker a = 0.2 ~ 0.7
arm shaft & bearing A = 25 a’ = 0.2 ~ 0.7
Tappet and tappet guide B = 50 b = 0.025 ~ 0.08 0.2

Tappet roller & Shaft C = 30 c = 0.020 ~ 0.066 0.2

bearing D = 45 d = 0.050 ~ 0.091
E = 26 e = 0.15 ~ 0.40
F = 10 f = 0.025 ~ 0.066

8
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

Cylinder Head-

Cylinder head decarb involves following procedures:

1) Assembly/Disassembly of Rocker arm

2) Assembly/Disassembly of Fuel valves
3) Assembly/Disassembly of Indicator cocks
4) Assembly/Disassembly of Suction/Exhaust valves
Caution: With proper markings
5) Assembly/Disassembly of Suction/Exhaust valve guides
to prevent exchange of Inlet and
6) Assembly/Disassembly of Suction/Exhaust valve seats
Exhaust valves.
7) Assembly/Disassembly of relief valve
8) Cleaning of cylinder head and all passages.

Cylinder head dismounting from engine involves:

1) Disconnecting suction/exhaust pipes

2) Disconnecting jacket water pipes
3) Removal of fuel injectors and fuel oil pipes
4) Removal of lubricating pipes.
5) Removal of air starting pipe(engines fitted with distributor system)
6) Removal of rocker arm
7) Removal of valve tappet rod.
8) Removal of indicator cock and relief valve.

Cylinder head overhaul involves:

1) Soaking cylinder head in water.

2) Removal of suction/exhaust valve guides (condition monitoring)
3) Replacing suction/exhaust valve seats (condition monitoring)
4) Replacing suction/exhaust valve seat O-rings.

Rocker arm assembly-

Rocker arm assembly and disassembly should be as per makers instruction.

While assembling ensure correct torque values are followed as per maker.

ADJUSTING SCREW

LOCK NUT

9
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

Following to be checked-

Exhaust valve yoke pin

S.No Observation Cyl No.1 Cyl No.2 Cyl No.3 Cyl No.4 Cyl No.5 Remark
Exh. FPP Exh. FPP Exh. FPP Exh. FPP Exh. FPP
1 Pin surface any See
scratches note
2 Pin lubrication YES/NO
passage to
clean
3 Yoke free to run YES/NO
on pin
4 Yoke pin
renewed/reused
5 Guide renewed
or reused
6 Go-NoGo-
Gauge v/v guide

Inlet valve yoke pin

S.No. Observation Cyl No.1 Cyl No.2 Cyl No.3 Cyl No.4 Cyl No.5 Remark
Exh. FPP Exh. FPP Exh. FPP Exh. FPP Exh. FPP
1 Pin surface any See
scratches note
2 Pin lubrication YES/NO
passage to
clean
3 Yoke free to run YES/NO
on pin
4 Yoke pin
renewed/reused
5 Guide renewed
or reused

Note- Scratches indicate improper v/v tappet adjustment which eventually leads to breaking of valve,
damage to liner piston etc.

Adjustment of balancing yoke-

As two suction/exhaust valves are pressed by one yoke

simultaneously, the yoke should be well balanced by precise
adjustment as follows-

1) Rotate crankshaft so that valves are in fully closed position.

The corresponding cylinder needs to be around firing TDC.
2) Check both push rods are free from spring forces and have
clearances.

10
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

3) Loosen the lock nut (1,3) and adjusting screw (2,4).

4) Press the non-adjusting side of yoke in order to make contact with top of the valve stem (A)
firmly.
5) While contacting (A) by pressing, rotate the adjusting screw (2) until contacting with top of the
valve stem (B). For easier sensing of contacting a dial gauge can be put on the valve rotor and
movement of needle could be checked.
6) Press (A) side of the yoke and measure the clearance of (B) by feeler gauge.
7) Similarly, press (B) side and measure clearance of (A) side by feeler gauge.
8) Unscrew the adjusting screw slightly and measure the clearance in turn by pressing the other
side of the yoke.
9) Repeat the steps until clearance of both sides are of same value and tighten lock nut (1) by
holding the adjusting screw (2) which should not be allowed to turn.
10) After locking measure clearance at both sides for confirmation.

Following to be checked-

S.No. Observation Cyld. No.1 Cyld. No.2 Cyld. No.3 Cyld. No.4 Cyld. No.5 Remarks

Exh. FPP Exh. FPP Exh. FPP Exh. FPP Exh. FPP
1 Rocker arm Standard
Brg.bush Dia. value/Limiting
value
2 Rocker arm
lube oil flow

Adjustment of valve clearance:

INSERT FEELER GAUGE HERE

After adjusting the yoke balancing, valve clearance to be adjusted as follows-

1) Cheak wear parts of rocker arm assembly. YES/NO

2) Check nut (5) for fixing rocker arm tightened to corect torque. YES/NO
3) Loosen the lock nut (3) and adjusting screw (4) of rocker arm.
4) Put a dial gauge on the yoke and insert a feeler gauge between rocker arm and yoke . Refer to
makers clearance limit.

11
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

5) Rotate the adjusting screw (4) until bottom of the adjusting screw makes contact with the push
rod. The dial guge needle will start moving as soon as the contact is established.
6) Tighten lock nut (3) while holding the adjusting screw (4) which shouldn’t be allowed to turn.
7) After tightening measure the clerance again by pressing the push rod side of rocker arm firmly.
YES/NO

S.No. Observation Cyl No.1 Cyl No.2 Cyl No.3 Cyl No.4 Cyl No.5 Remarks

Exh. FPP Exh. FPP Exh. FPP Exh. FPP Exh. FPP

1 Exhaust v/v
yoke
renew/reuse

2 Inlet v/v yoke

renew/reuse

3 Lube oil
passage
blown through

4 Go-NoGo-
Gauge

. Cylinder Head valves, valve seats and valve guide assembly/disassembly

Dismounting of Inlet and Exhaust valves

Before dismantling the valves cylinder head to be dismantled. Following steps to be followed-

1) Rocker arm, yoke and fuel injection valve to be dismantled first.

2) All four valves to be numbered with as S1,S2 (for suction valves) and E1, E2 (for exhaust valves)
and at same time their corresponding valve seats, valve guides and position in which they are
placed on cylinder head to be marked in same manner. YES/NO

12
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

3) Fix the compression tool for springs a shown.

Compression tool to force the springs down to remove the cotter

4) Press and lower the spring by turning the nut of the tool.
5) Remove the conical cotter.
6) Dismount the tool.
7) Remove the roto cap, springs and valves.

Dismounting valve guide-

Valve guide extraction tool

If valve guide clearances exceed makers recommended values, then it has to be replaced. Following
procedure for removal to be followed-

1) Use a tool as shown in the figure above.

2) Place the tool on the valve guide and extract it by using hammer on the extracting tool.

13
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

Valves stem guide measurement tool:

USING GO- NO GO GAUGE TOOL WHICH GAVE APPROXIMATE MEASUREMENT OF

STEM GUIDE:

For assessment of valve stem guide dimension for confirming its further use in service, initially
GO-NO GO gauges were supplied on vessel.

GO-NO GO gauge was fabricated to measurement of valve stem guide as per individual makers
stipulated limit which was effective in determining the further use of valve stem guide until next
overhaul.

In order to access the condition of the valve guide the above tool fabricated with a dia. of
19.24/19.22mm and length of 400mm with precision work. During each cylinder head o’haul,
this tool must be used to check the condition of the valve guide after proper cleaning . And if this
tool (dia. 19.24/19.22mm) passes through the valve guide then this valve guide must be
discarded.

19.24 mm for exh. V/v guide,

19.22 mm for suction v/v

GO-NOGO GAUGE FOR SUC V/V GO-NOGO GAUGE FOR EXH V/V

14
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

Following checks to be carried out-

Exhaust valve guide

S.No. Observation Cyld. No.1 Cyld.No.2 Cyld. No.3 Cyld. No.4 Cyld. No.5 Remarks
Exh. FPP Exh. FPP Exh. FPP Exh. FPP Exh. FPP
1 Diameter after Standard Diameter
cleaning mm acceptable limit
2 Carbon deposit See note below

3 Go-gauge going Yes/No

4 No-go gauge going Yes No

5 Guide renew/reuse Standard Diameter

acceptable limit
Inlet valve guide

S.No. Observation Cyl No.1 Cyl No.2 Cyl No.3 Cyl No.4 Cyl No.5 Remarks
Exh. FPP Exh. FPP Exh. FPP Exh. FPP Exh. FPP
1 Diameter after Standard Diameter
cleaning mm acceptable limit
2 Carbon deposit Yes/No

3 Go-gauge going Yes/No

4 No-go gauge going Yes No

5 Guide renew/
reused
Note: Guide to be cleaned thoroughly with reamer to remove hard carbon deposit and then check
with Go-No-Go gauge.

New stem guide measuring tool:

USING VALVE STEM DIA MEASURMENT MICROMETER, WHICH ASSISTS IN ACCURATE

MEASUREMENT OF VALVE STEM GUIDE:

This new measuring tool has been supplied on vessels for greater accuracy and will replace the
GO-NO GO gauge.

PIC 1: AE VALVE GUIDE DIAMETER MEASURING TOOL

PIC 2: THE MEASUREMENT OF VALVE GUIDE

DIAMETER IS BEING CHECKED WITH TOOL

15
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

PIC3: THE THREE ARMS MOVE IN OR OUT WITH THE

TURN OF VERNIER KNOB

VALVE STEM GUIDE DIMENSION MAKERS LIMIT FIT FOR FURTHER USE

SUCTION VALVE STEM

FUEL PUMP SIDE

SUCTION VALVE STEM

EXHAUST SIDE

EXHAUST VALVE STEM

FUEL PUMP SIDE

EXHAUST VALVE STEM

EXHAUST SIDE

Valve Seat Extraction

Tool

Valve seat can be extracted either by welding (if maker has not
provided any tool) or by makers/fabricated tool.

Removal of valve seat by welding-

1) Prepare a scrapped valve spindle and machine it to a

diameter small enough to be easily welded onto the valve
seat.

16
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

2) Place the valve spindle on the seat and weld it diagonally. Protect the machined surface around
the valve seat of the cylinder head by shielding it with non-inflammable material.
3) Press or knock the valve spindle by means of hammer to extract the seat ring.
Be careful not to damage valve guide bush and cylinder head.

Extracting old valve seat by tool-

1) Mount the extracting tool and plate on the valve seat as shown in figure above.
2) Clamp the valve seat tightly by turning nut “A”.
3) Extract the valve seat by turning nut “B”.

S.No. Observation Cyld. No.1 Cyld. Cyld. No.3 Cyld. No.4 Cyld. No.5 Remarks
No.2
Exh. FPP Exh. FPP Exh. FPP Exh. FPP Exh. FPP Recond.
1 Exhaust v/v seat Grinding/La
renew/reused pping
2 Inlet v/v seat Grinding/La
renew/reused pping

Assembling Suction/Exhaust valves

Checks to be carried out on valve and guide before assembly-

Part Name Nominal size Clearance as per Observed readings

maker
Suction v/v stem A = 16.00 a = 0.06 ~ 0.143
part and guide
Exhaust v/v stem A = 16.00 a = 0.08 ~ 0.161
part and guide
Guide Pin Yoke B = 20 B = 0.031 ~ 0.065

17
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

Suction valve Exhaust valve

Part Name Nominal size Clearance Tolerance as Observed

per maker readings
Suction valve C=6 R1 = -0o5’~0o 4.5
R1= 30o
Exhaust valve E=6 R3 = 0o5’~0o 4.5
R3 = 30o

Following information’s to be filled in

SNo. Description Cyld.1 Cyld.2 Cyld.3 Cyld.4 Cyld.5 Remarks

Ex. FPP Ex. FPP Ex. FPP Ex. FPP Ex. FPP

1 Exh V/V Stand.Dia=

Steam dia
at three Allow.limit=
points (mm)
2 Inlet V/V Stand.Dia=
Steam dia
at three Allow.limit=
points (mm)
3 Exh V/V
renewed:
Yes /No
4 Exh V/v
after recond If on board
- Onboard/ mention
shore grinding/lapping
5 Inlet V/V
renewed:
Yes /No
6 Inlet V/v If on board
after recond mention
- Onboard/ grinding/lapping
shore

18
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

Final assembly of Suction/Exhaust valve

1) The valve, springs and roto caps should be cleaned, checked for cracks by dye penetration test and
then mounted on the cylinder head. YES/NO
2) Rotocap bearings and springs should be checked and replaced if necessary. YES/NO
3) Valve guides and seat rings should be thoroughly cleaned and apply some oil inside valve guides to
facilitate easy assembly of valve. Valve guide o- rings to be renewed. YES/NO
4) Coat some lube oil on the valve stem and each valve (suction/Exhaust) should go into same place
as they were originally. This has to be verified by the reference marking on the valve as well as on
the cylinder head which had been made before dismantling the valves from head. YES/NO
5) Assemble valve spindle into the valve guide and check there should be smooth sliding movement
between the two. YES/NO
6) Once the valves are located in respective positions, mount the springs over the spindles and place
roto cap over the springs.
7) Use the same compression tool which was used earlier for dismantling to push the springs down.
8) Insert cotters into clearance space between valve stem and roto cap to complete the assembly.
9) Lightly tap the end of each valve stem with hammer to check the bouncing effect of valve. YES/NO

Following checks to be carried out-

S.No. Observation Cyld. No.1 Cyld. No.2 Cyld. No.3 Cyld. No.4 Cyld. No.5 Remarks

Exh. FPP Exh. FPP Exh. FPP Exh. FPP Exh. FPP
1 Ball How many
renewed
2 Spring How many
renewed
3 Ball race How many
renewed
4 Disc spring How many
renewed

19
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

Fitting new suction/Exhaust valve seat into the cylinder head-

Tool for suction valve seat ring Tool for Exhaust valve seat ring

Checking clearances of suction and exhaust valve seats-

Suction valve Exhaust valve

Part Name Nominal size Clearance Observed

readings
Intake valve seat R2 = 30o R2 = 0~0o5’ R2=
Exhaust valve F = 0.38 R4 = 0~0o5’ R4=
seat R4 = 30o

If it is required to change the valve seat, then following steps to be followed-

1) The cylinder head valve seat housing should be properly cleaned and inspected for cracks.
YES/NO
2) Valve seat ring to be inserted into the cylinder head should be cooled and then pressed in with
tool as shown in the figure.
3) Lapping/grinding of valve seat to be carried out by makers provided tool or by old exhaust
/suction valve using coarse grinding paste at first and then finishing to be given using fine
grinding paste.
4) At the end of the process the new valve suction/exhaust should be used with fine grinding paste
with respective valve seats suction/exhaust, for final bedding. YES/NO
5) To confirm whether the valve and seat contact surfaces are bedding together, persian blue paste
can be used on the surface of valve seat or valve at contact faces. There should be uniform
imprint of blue layer on both valve as well as seats contact surfaces. YES/NO

20
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

Mounting of valve guide

USE GO-NOGO-GAUGE/MICROMETER TO CHECK IF VALVE GUIDE

CAN IS NOT DEFORMED AFTER INSERTING IN THE CYLINDER
HEAD:

1) Clean & inspect all four valve guide housing in cylinder head. YES/NO

2) Valve guide to be inserted has to be cooled.

3) Valve guide to be applied with lubricating oil on the outer face which will enter the cylinder head.
YES/NO

4) Valve guide to be inserted in by using hammer. Do not hammer directly on valve guide. Use a brass or
lead bar between hammer and the valve guide contact surface.

5) After inserting the valve guide, check internal diameter of valve guide using Go-No Go-Gauge or
micrometer tool.

21
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

Piston assembly /disassembly

STEP 1 STEP 2

Clamping support Bracket

STEP 4 STEP 3

After dismounting cylinder head from the engine, following steps to be followed to remove the piston rod-

1) Remove the flame ring and clean the threaded hole in the piston crown.
2) Install lifting eye on the piston threaded hole. The eye bolt should sit flush with the piston crown.
3) Turn the crankshaft 25o approximately.
4) Install clamping support on connecting rod shaft and big end part.
5) Loosen four nuts on connecting rod hydraulically and remove nuts and studs.
6) Turn the crank shaft to TDC.
7) Install bracket on connecting rod big end part and counter weight.
8) Dismantle the clamping support.
9) Lift up the piston along with connecting rod slowly out of the liner and place it on the stand as
shown above.

22
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

Dismantling piston and piston rings-

1) Install eye-bolt on the piston crown and hook it up.

2) Lift up the piston along with connecting rod from the stand and place it gently on a wooden table.
3) Remove the circlip and push the piston pin out gently.
4) Lift the piston up while supporting the connecting/piston rod.
5) Remove piston rings with plier provided by maker and if not provided then it can be removed with
screw driver and rage. While removing the piston rings attention to be paid that it should not be
over stretched so that it deforms.
6) Remove all carbon from piston and piston ring grooves.
7) Inspect the ring grooves and measure the clearances and confirm within makers limits or not.

23
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

PART Piston ring Clearance End Replacing Replacing Observed

groove clearance limit limit readings
height
6.150 ~ B1=0.13 ~ 0.50
1st ring
6.120 0.175
5.120 ~ B2=0.10 ~ 0.50
2nd ring
5.090 0.145
6.060 ~ B3=0.05 ~ 0.3
Oil ring lower
6.040 0.085

Description Cyld.1 Cyld.2 Cyld.3 Cyld.4 Cyld.5 Remarks

Piston ring grooves cleaned

Piston ring fitted with stamp mark on top

Remark: Piston grooves to be cleaned with copper only. Screwdriver or welding rods not to be
used. YES/NO

Description Cyld.1 Cyld.2 Cyld.3 Cyld.4 Cyld.5 Remarks

Piston Crown Condition

Piston Crown bolts

Renewed/reused

New Crown bolts bedded

prior final tightening

Locking of the crown

bolts carried out as per
maker

Crown replacement -
Blue test carried out

Piston rings fitted

keeping the stamp mark
on top

Crown Interior cleaned

with solvent

24
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

8) Inspect for cracks on piston.

Piston Crown crack detection Piston ring grooves cleaned

9) Inspect piston bush and measure clearances as per maker’s instruction and limits.

Position (all readings are in mm) #1 #2 #3 #4 #5 Max Limit

Dia. of Boss A (ID of Piston Pin hole)

Dia. of Bush B (ID of Piston Pin Bush

metal)

Dia. of Pin X (OD of Piston Pin)

a = A-X

b= B-X

Clearance with feeler gauge (Boss & Pin)

25
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

INSPECTION OF PISTON BOLT TENSION

Piston for HiMSEN engine has been improved continuously to ensure the tightening connection between
Piston Crown & skirt. For 5 H21/32 engines, 4 Stud design have been used.

H21/32

1) Turn the piston upside down and rest on soft (wooden) surface.
2) Loosen the piston bolts using the torque spanner and remove the piston crown.
3) After removal of piston crown following checks to be carried out.

26
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

Vessel Name:
Engine No.
Description Cyld.1 Cyld.2 Cyld.3 Cyld.4 Cyld.5 Remarks

Piston Crown
Condition

Piston Crown bolts

Renewed/reused
New Crown bolts
bedded prior final
tightening
Locking of the
crown bolts carried
out as per maker
Crown
replacement - Blue
test carried out
Crown Interior
cleaned with
solvent

Remark 1: In case of crown bolt renewal, each bolt is to be bedded prior final tightening by tightening to full and
then loosening back. Molykote 1000 is to be applied every time. YES/NO

Remark 2: In case of crown renewal, blue test is to be carried out to confirm 100% contact with the skirt. YES/NO

4) Coat thread & contact surface of stud with “Molycote-paste G-n plus or G-n & then tighten the stud with a
torque of 25 Nm to assemble to crown diagonally.
Notice: If only the length of stud is less than 84.3 mm, re use the Piston stud.

5) Coat thread of studs with molycote paste & assemble piston skirt to crown. Before assembling washers,
coat contact surface with molycote paste.
6) Tighten the nuts with a torque of 40 Nm, loosen the nuts again & re tighten the stud bolt with a torque of 25
Nm for checking.
7) Continue tightening the nuts with a torque of 20 Nm one by one & turn the nuts by an additional 60 o.
Notice: Make sure that the nut is not rotated by application of test torque 45 Nm to tighten direction.
If the nuts can be turned any more, renew the stud & nut.

Pressure washers are used to disburse the compression of the nut or bolt smoothly. This lessens the possibility of
damage and offers a flat space for the nut or bolt to stay, meaning it will be more likely to stay in
one place.
The pressure washers are used since the hole is a larger diameter than
the fixing nut.
It is extremely important to clean the surface of the washers & coat the
contact surfaces with molycote before assembling so that the correct
hydraulic pressure applied is retained.

27
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

Assembling piston pin and piston rings-

1) Coat the surface of piston pin and small end bush with oil and mount piston pin into small end
bush through the connecting rod.
2) Mount circlips for piston pin.
3) Lift the piston and connecting rod assembly and place it on the stand.
4) Mount the piston rings into the piston groves using makers designated tool. Precaution to be
maintained not to expand the ring too much as it will be deformed and will not of spring function
required for sealing.
5) End gaps of each piston ring should be arranged at 120 degree in relation to each other. YES/NO
6) Inspect the piston ring for wear as shown. If the wear limit exceeds makers limit then the ring
should be replaced. YES/NO
7) Mount the piston along with connecting rod into the engine.

1st and 2nd ring Scrapper ring

Clearance = 0.50 Clearance = 0.30

Dismounting Cylinder liner from engine-

28
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

Removal of cylinder liner-

1) After removal of piston out from the liner mount cylinder liner lifting tool on the liner as shown.
2) While removing the liner out from the jacket a reference mark has to be made on the liner as well as
on the fixed jacket, so that liner if installed in same position.
3) Place the liner on wooden blocks.
4) Replace the liner O-rings with new. YES/NO
5) Clean the jacket inside surface as well as line outer surface. YES/NO

Measurement points in cylinder liner to be checked-

Measurement at 3 points in a liner to be carried out and readings compared with makers limits.

Max. wear allowed-

S.No. F/A P/S

1
2

3
Ovality of liner to be checked.

Mounting cylinder liner in water jacket-

1) After replacing old O-rings on the liner with new ones, smear grease
on the o-rings.
2) While placing liner in the jacket match the position pin and groove by
aligning the reference markings made before removing.
3) After mounting check height of the cylinder liner from top of the water
jacket.

29
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

Bottom end bearing-

Dismantling of bottom end bearings fitted with hydraulic bolts-

1) Move the piston to TDC.

2) Install holding supports on big end parts.
3) Loosen the two hydraulic nuts on the studs of the big end part. Loosening
pressure to be referred in makers manual.
4) Support the bottom part of the bottom end bearing either by placing
maker’s tool or if not, then a wooden plank to be placed to support the
bearing.
5) Remove the nuts and studs of bottom end bearing.
6) Lower the bottom shell on to the wooden plank or makers support tool and
remove it from the crank case.
7) Loosen bolts of holding support.
8) Mount a bracket on the engine block.
9) Turn the crankshaft to cam side approx. 5 deg. slowly.
10) Fit the big end upper part and bracket with a bolt.
11) Turn the crankshaft 45 deg. approximately.
12) Take out upper bearing from the housing. The upper and lower bearings need to be marked for
identification so that they do not get mixed up.
13) Inspect the big end bearings.

Holding supports

Fig.1 Fig.2

Extracting lower end bearing. Installation of bracket Extracting upper end bearing

30
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

Description Cyld.No.1 Cyld.No.2 Cyld.No3. Cyld.No4. Cyld.No5. Remarks.

Connecting Rod
Renewed/Reused
Dye check for the
serrations
Megna-flux test for
the Serrations
Lube oil passage
cleaned with
solvent
Condition of piston
pin bush

Bottom end
bearing housing
cleaned with
scotch Bite
Bearing shell back
plate cleaned with
scotch bite
Close up
Photograph of the
bearing shell sent
to office
Prior installation -
Clean oil applied
on the bearing
shell running
surface
Free axial
movement
checked after full
tightening

31
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

Remark 1: Bearing shell back and bottom bearing housing should be absolutely dry before installing the
bearing. YES/NO

Remark 2: Bearing shell is to be placed in the middle of the bearing housing, axial position. YES/NO

Remark 3: A few good photographs to be taken after placing all bottom end bearing shells in line, this is
to understand the loading patterns on the bearing. YES/NO

Mounting of Big end bearings-

1) Before mounting the bearings check the ovality of crank pin by external micrometer at vertical and
horizontal direction.

crank pin ovality measuring points

32
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

2) Put the bearing shell into the casing and to ensure that the shell is inserted in the casing in right
direction. The ends of top and bottom shell should match and notch on the shell should fit into
casing groove. Do not apply lube oil on back of the bearing shell while placing it in the bearing
housing.
3) Once the upper bearing shell is mounted in its housing place it on the crank pin.
4) Loosen and take out bolts for bracket.
5) Move the crankshaft to TDC.
6) Dismount the bracket.
7) Mount the lower bearing to the housing.
8) Lift up lower bearing housing to contact with upper

9) Cam Effect:

Description: Cam effect is uneven wearing of auxiliary engine crank pin journal which causes
change in its geometry.

Cause: Small abrasive particles suspended in lube oil cause the wear of the crank pin journal.

Small abrasive particles causing wear in crank pin journal which causes wear on either side of
lower bearing shell oil groove

Location: The cam effect is observed on the center part of crank journal which protrudes out as the sides
of the crank pin journal wears out due to small abrasive particles suspended in lube oil.

33
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

Center Protruding part of the crank pin (protruding out as cam) cause overloading on
center part of upper bearing shell

Consequences of cam effect:

Cam effect on crank pin journal affects the top crank pin bearing shell causing scuffing and
smearing of the bearing top layer.

Top crank pin bearing shell & crank pin damage due to cam effect

34
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

Detection of cam effect:

Cam effect can be determined by following methods:

1) Visual method: using “straightedge tool” and placing it horizontally on crank pin journal and
placing light source behind the straight edge tool and observing the contact point of tool with
crank pin.

Visual indication of cam effect

2) Once it has been detected that cam effect is present, following is the procedure for
confirming:

Tools for measuring cam effect:

 Paste (special paste having ferrous content)

 Gauge block (steel, ceramic material)

35
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

Gauge blocks of different size available from “Mitutoyo precision company”

 Apply paste uniformly on crank pin over the area where cam effect is detected.

 Use gauge block and press the flat surface on the cam effect zone over the paste.

 Impression of the paste on gauge block at center part which is broken and not uniform along
the entire length of gauge block, confirms cam effect has occurred.

Impression only on center part and broken

Along length of gauge block

For rectifying the cam effect, cam has to be polished or in extreme case requires to be
machined.

36
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

Crank pin polishing and machining is precision job which requires service engineer’s
attendance.

Measuring cam effect:

Crank pin Straight edge light appearing Impression on template

Number
Y/N (Uniform or broken)

Assembly of bottom end bearing-

While assembling the bottom end bearing utmost care has to be taken-

1) Clean the bearing housing nice and dry. YES/NO

2) Place the bearing shell correctly in appropriate housing. Lower bearing shell should go in
lower housing while upper bearing should go in upper bearing housing. Do not mix the bearing
shell and its respective housing. Photograph of correct placement of bearing shell in its housing
to be taken. YES/NO

3) No oil is to be applied at the back of the bearing shell or on the surface of the bearing
housing where bearing shell slides in. YES/NO

4) The bearing shells should be placed right at the center of the housing. YES/NO

5) Place the bearing shell on the connecting rod and screw in the bolts by hand. Apply
molybdenum disulfide to the bolts before tightening. YES/NO

6) If same connecting rod bolts are being used ensure that same bolts go in the same position
in bottom end bearing shell as they were before being removed.
If new bolts are being used then the bolts have to be tightened and loosened 3 times from/to its
surface position to/from to its specified angle position for proper bedding so that it fully tightens to
the seat face. YES/NO

7) Tighten the bolts to correct torque or specified angle as per maker’s instruction. Tighten the
bolts in following order-
If 2 bolts are there tightening order should be: 1-2-1-2

37
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

If 4 bolts are there tightening order will be: 1-4-3-2-1

The bolts have to be evenly tightened.

8) Once the bolts are tightened-

For reused bolts- the punch mark made before disassembly should coincide after tightening to
same torque/angle during assembly. YES/NO
If new bolts are used then after tightening to prescribe makers torque/angle, punch marks on the
bolt head and bearing housing to be made for reference. YES/NO

9) After final tightening slide the bottom end bearing on the crankshaft axially. It should slide
freely. YES/NO

Bottom End Bearing Overhaul

Removal of Bottom end Bearing after Piston Removal from Cylinder

1) Remove piston from cylinder unit after loosening the bolts “A” on connecting rod.
2) After piston is removed from the cylinder unit, turn the crankshaft to 10 o approximately as shown in
fig. 5 so that the bottom end bearing bolts “B” is facing towards the crank case cover doors.
3) Loosen & dismount two nuts for big end part studs hydraulically at the same time. Loosening
pressure: 970 bar (max 988 bar).
4) Install guide support on the bottom of the engine as shown in fig. 6
5) Turn the engine to 5o approximately & dismount the turning bracket.
6) After removal of big end bottom end bearing bolts, remove the big end upper & lower bearing shell
covers & take then out from the engine block as shown in the fig below.
Notice: Be careful not to drop or damage the bearings during taking them out of the engine.

7) Inspect the crank pin thoroughly by turning the crank shaft.

8) Put tapes on the oil hole of the crank pin to avoid any dirt going inside. Be sure to take out all the
tapes before re assembling.
9) Inspect any damages in the joint faces between the connecting rod shaft & big end upper part.
10) Inspect the damages in threads of studs & nuts for tightening the connecting rod shaft & big end
upper parts.
Notice: If studs/nuts have damages in threads and/or on the contact surface, then they
should be renewed.

38
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

11) Mark the bearing shells in the bearing housing and the position in which it is placed in bearing
housing, for reference.
12) Remove the bearing shells from the bearing housing and inspect the same for thickness, condition
of surface as shown below.

13) Inspect for following-

a) Fretting on crank pin shell
b) Inner surface of shell for seizure marks, peeling, cavitation.
c) Check for any imbedded foreign particle on the inner shell
14) Clean the shell and measure the thickness “T” of the shell with micrometer and record the results
15) Clean the bearing housing and measure the inner diameter “D” with micrometer and record the
results.
16) Measure the diameter “A” of crank pin and record the result.

Observation # Unit1 # Unit2 # Unit3 # Unit4 # Unit5 Remarks

Inner Dia. Of large end housing(mm)
D, without shell

Thickness of the bearing shell (mm)-T

Dia. Of the crank pin “A”

Clearance ‘a”= D-2T-A

39
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

Following observations to be recorded for bearing shell inspection:

Description Cyld.No.1 Cyld.No.2 Cyld.No3. Cyld.No4. Cyld.No5. Remarks.

Connecting Rod
Renewed/Reused
Dye check for the
serrations
Megna-flux test for
the Serrations
Lube oil passage
cleaned with
solvent
Condition of piston
pin bush

Bottom end
bearing housing
cleaned with
scotch Bite
Bearing shell back
plate cleaned with
scotch bite
Close up
Photograph of the
bearing shell sent
to office
Prior installation -
Clean oil applied
on the bearing
shell running
surface
Free axial
movement
checked after full
tightening

40
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

Connecting Rod

The connecting rod transfers the entire generated power out of the combustion process from the piston
pin to the crankshaft and converts the reciprocating energy into rotating energy that drives either the
propeller or the generator. The “connection piece” between the piston and the crankshaft is the
connecting rod. Like all other engine parts that are directly involved into the combustion process, the
connecting rod is highly stressed. The con rods alternating, comparative stress is mainly fed by 3 different
forces:
 the acceleration force, from the combustion process
 the mass force, from the piston and the piston pin
 the bending force, caused by the con rod angle

With a share of approximately 80%, the connecting rod shaft is mainly loaded by
dynamically acting compression stresses out of the combustion process. The
remaining 20% are dynamically acting bending loads. This results in a very
complicate stress profile in the connecting rod eye (or small end) while engine
operation.

The connecting rod shaft can be manufactured in a "H"- or "O-profile" (round cross
section). Today´s engines - with high specific outputs - are equipped with fully
machined con rods. For manufacturing reasons, they have an O-profiled shaft.

For the lubrication of the piston pin as well as for the piston cooling, the con rod shaft
is very often drilled longitudinally.

The upper end of the connecting rod is the connecting rod eye. This accommodates an undivided piston
bolt bearing - the so called small end bearing. The lower end of the connecting rod is divided into two
halves, as the connecting rod is guided through the cylinder from above - the so called big end bearing.
Initially the big end bearings were divided horizontally. When the specific output of the engines increased,
larger surfaces for the bearing became necessary and they developed con rods with diagonally split big
ends in order to pull the con rod upwards with its foot through the cylinder liner.
In order to avoid that the big end bearing housing must be opened during maintenance of the piston,
Himsen Engine connecting rods are divided between con rod shaft and big end bearing housing.

The screwed connection of the big end bearing housing is one of the most difficult connections
for screws due to the high asymmetric load on them. This lead into dynamic bending stress, that
must be handled by the tightening forces. Because of this, the tightening procedure needs
extremely high attention.

Due to the cranking of the con rod during combustion and compression - inside the cylinder - the big end
bearing is subject to asymmetric forces which creates asymmetric and dynamic wear and tear. Therefore,
the ovality of the big end bearing houses has to be checked on a regular basis. Due to the high forces,
the mating surface between the lower half and the upper half of the big end bearing housing need´s the
highest grade of planarity, in order to avoid fretting wear and tear.

41
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

Preventive measure for Con rod:

The exact dimensions of the connecting rod, as well as his geometry (e.g. the ovality of the big end
bearing housing) shall be checked on a regular base during each maintenance.

Dimensions and condition of the connecting rod

The mating surfaces of the bolts and the threads shall be in proper condition and not be affected by rough
handling, because small damages can be the starting point of fatigue cracks.
Note: New con rod bolts are cheaper.... than a new engine!

It is absolutely necessary to get reliable measurements for taking the right decisions:

 Measuring the diameter and ovality of a big end bearing housing requires full tightened
connecting rod bolts with assembled connecting rod shaft
 Requires also to make use of the correct lubricant for bolts and nuts (in accordance to
Maker’s recommendation)
 Requires also that the temperature of the housing, the calibrating and the measuring device is as
equal as possible
 Requires also to calibrate your measurement device before carrying out the measurement
 Requires to use of the correct lubricant for the assembling parts (bolt, nuts etc.)

Use of lubricants while assembling of parts

Maker’s manual contains the information what kind of lubricant must be used. It is important to
understand that this is an instruction and not just a recommendation which can be ignored or neglected if
the correct lubricant is not available. Ignoring or neglecting this instruction may result in a significant
deviation of the required tightening forces! And if this happens... good luck for your engine...

How much lubricant should be used? Much helps much? No, it´s just the opposite.

The job of a lubricant is to reduce the friction between the threads of bolts and nuts. A thin layer of the
lubricant is enough; unless it is otherwise stated by the engine manufacturer. Just for your information,
some of the manufacturers during final assembling of pistons, use tooth brushes for the smaller and bottle
brushes for the larger threads to ensure just a thin layer of the lubricant.

Need an example? Here it is: Assembling a MAN 16/24 piston with too much Molykote on the thread of
the bolts (dipping the bolts into the Molykote) will result in a loosening torque that is more than 40% lower
than required. As a consequence, the piston crown becomes loose in engine operation. There are cases
on board of several vessels when the crown was changed by the crew some years ago & rest goes to the
history book!

Note: As the size of the measurement to be measured increases, the measuring error also increases at
deviating temperatures between the engine component, the calibrating and the measuring device.

A temperature difference of only 6°C (assumed 28°C of the housing and 22°C of the measuring device)
between a big end bearing housing with an assumed bore diameter of e.g. 450 mm and the measuring
device will result in a measuring error of approximately 0.03 mm ! The "as new" tolerance of in this bore
range usually is only +0.04 mm.

42
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

Condition of connecting rod bolts

The surface of the bolts and the threads shall be in proper condition and not be affected by rough
handling: Small damages can be the starting point of fatigue cracks.

NEVER ! use new and used assembly components at the same conrod.

Correct tightening of connecting rod bolts

Make sure that the bolts are tightened in complete accordance to the Maker’s instruction in all regards
like e.g. - the tightening stages, the correct lubricant and of course => no use of hammers and other
heavy tools. The mechanical stress to the connecting rod is enormous and a damaged con rod will
release a disaster – mostly the total loss of the engine. Therefore, correct maintenance is essential.

For 5H 21/32,

1) A = 190 mm,

2) Shell thickness,T = 4.925 mm

3) Clearance, a = 0.133 ~ 0.231 mm

Observation Unit #1 Unit #2 Unit #3 Unit #4 Unit #5 Remarks

Nominal 190
size(mm)- “A” as
per maker
Standard 0.133 ~
Clearance(mm)- 0.231
“a”, as per maker

43
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

Observed Nominal
size- “A” by vessel

Observed
clearance(mm) “a”
by vessel
Replacing limit 0.3
(mm), as per
maker

17) Bearing shell to be replaced as one set i.e. both upper and lower bearing shells to be changed
together as a pair. YES/NO

Measuring ovality of end bearings.-

To measure the ovality and to perform dye penetration test to determine the cracks on the serration, the
bottom end bearing assembly has to be removed out from the crankcase.

This process can only take place once piston has been removed along with connecting rod out of the
cylinder liner.

1) Remove piston and connecting rod out of the liner and place it on a stand (fabricated by ship
staff)
2) Bottom end bearing part to be removed by loosening the hydraulic nuts as stated above.
3) Support to be placed underneath bottom end bearing.
4) Lower the bottom end part and remove it out of the crankcase.
5) Similarly top end part of bottom end bearing too can be removed.
6) Place both the parts on wooden block and perform dye penetrant test on the serrations of bottom
end bearings.
7) Remove bottom end shells after marking each as top/bottom if to be used again. Reference
markings to be made on shell s well as on the casing too, so that while assembling it provides
easy reference to put shell back in its place in right direction. YES/NO
8) Tighten the casing hydraulically as stipulated by maker. YES/NO
9) With a micrometer measure the ovality of the big end bearing casing at different point shown-

Points to measure Removal of Bearing Dismantling of bearing

44
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

10) Check the elongation of bottom end bearing studs. If elongation exceeds makers limit same to
with new. YES/NO

11) Dye penetrant test to be carried out on bearing studs to check for cracks. YES/NO

12) Check the surface of bearing shell and measure the thickness with micrometer. Compare it to
makers limit. Bearing surface to be checked for erosion, pitting and removal of metal layer.
YES/NO

Replacing connecting rod bolts-

Vessel Name-
Date-
Checks to be carried out before starting generator

Observation Cyld.1 Cyld.2 Cyld.3 Cyld.4 Cyld.5

Crack case cleaned manually

Checked for cooling water leakage prior taking oil

Lube oil filter casing drained and filter element cleaned

Crank shaft deflection checked prior & after o'hauling

Calibration tools warmed up prior use

Engine is free to turn with turning gear

Fuel pump and system purged prior starting

Checked for the lube oil flow to Roto caps

Manual lubrication carried out for the rocker arm and vlve yoke

Manual lubrication carried out for Fuel pump racks

Remark 1: Calibration tools to be kept near the engine for atleats 4 hours prior use.
Remark 2: For fuel pump rack lubrication, use a mixture of lube oil and diesel (50:50)

45
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

Small End Bush Overhaul

1. Check the surface of the piston pin & small end bush

2. Measure clearance between the piston pin & small end bush

3. If the specified limit is exceeded, the bush need to be replaced using the removal device. During
removal of the bush, make sure that the bore should not be damaged.

4. Insert the bush to bore correctly after the bush is shrink fitted.

Notice: Clean & coat the bore with clean lubricating oil before inserting.

46
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

Vessel Name-

Date-

Running in checks-

RPM Load Duration Air/Fuel Main brg. Temp deg. Con rod play Filter condition
cent
#1 #2 #3 #4 #5 #1 #2 #3 #4 #5
Slow( Idle 2 min Air
140)
Slow( Idle 30 sec DO
320)
Full Idle 30 sec DO

Full Idle 1 min DO

Full Idle 2 min DO

Full Idle 5 min DO

Full Idle 15 min DO

Full Idle 30 min DO

Full Idle 1 hr. DO

Full 200k 15 min DO

w
Full 400k 30 min DO
w
Full 400k 12 hrs. HFO
w
Full 600k 30 min HFO
w
Full 650k 30 min HFO
w
Exhaust temp @400o C

Exhaust temp @ 450o C

47
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

Overhauling Of Charge Air Cooler

Prepare correct tools and lifting equipment’s for the work concerned.

Spares that will be consumed have to be available on board prior to commencing the work.

1) Stop and secure the engine.

2) Close all cooling fresh water valves In/Out to engine and confirm that valves are holding.
3) Close venting valve to Expansion tank and confirm the valve is holding.
4) Drain the water from the cooler and open vent plug at some higher point in the system to facilitate
draining.
5) Keep and vigilant eye on the expansion tank level as draining is continued, as loss of water from
expansion tank during the process will indicate one of the valves is either not closed or leaking.
6) Remove the bolts of the front cover except two diagonal bolts; leave it on the cover securing it.
7) Attach chain block to the eyebolt secured to cover with its surface flush with the surface of the
cover.
8) Screw in two studs at opposite sides of the cover and remove the two diagonally located securing
bolts holding the cover in place.
9) The studs screwed into the cover should be long enough so as to allow the cover to slide onto it
while removing, so that cover is evenly supported.
10) By screwing in the jacking bolts of correct size equally and evenly into the jacking holes provided
on the cover at opposite sides of the cover, slide the cover of the air cooler body.
11) Remove the air cooler gasket.
12) Then slide off the air cooler slowly and evenly without damaging the fins from the casing using
the chain block.
Note: Utmost care to be observed during this process.

13) Submerge the air cooler in Air cooler cleaning chemical bath or alternatively if the air cooler can
be suspended by chain block in ultrasonic machine (without resting in the machine) and cleaned.
Note: Do not use strong chemicals. Use Air cooler cleaning chemical only.

48
 Anglo Eastern Ship Management (Singapore) Pte Ltd
AE OVERHAUL PROCEDURE AND CHECKLIST
AE OVERHAUL No - UNIT No:
DATE OF OVERHAUL:

Assembly of air cooler-

Following checks to be carried out after cleaning-

1) Inspect the fins and confirm they are not damaged.

2) Check for corrosion.
3) Removing fouling and deposit in intermediate piece of cooling water pipe.
4) Ally some grease on to the intermediate piece.
5) Place new gasket.
6) Tighten bolts to correct torque.
7) Crack open cooling water inlet valve. At the same time vent valve for cooler should be open.
8) Observe for any leaks on the cooler.
9) After all air trapped in the system is purged out close the vent valve and open the air cooler
outlet valve.
10) Open the air cooler inlet valve fully.
11) Observe for any leaks.
12) Expansion level to be monitored during the entire process of commissioning air cooler into
service and eventually topped up with water, after system operational.

49