Diesel Customer Information No.

289

Action Code:
When Convenient

Backround Check of Valve Rotation

Many years of experience with the engines in operation Changes in maintenance
has resulted in a positive development in relation to the schedule
maintenance work for checking the valve rotation of inlet
valves. DCI / 289 - March 2010

The valve rotating devices used by MAN Diesel have Concerns

proven to be reliable and resistant to failure over their Four-stroke engines 32/40, 32/44CR,
service life of 24,000 hours. 40/54, 48/60, 51/60DF, 58/64

This has enabled the maintenance work for checking Summary

the valve rotation of inlet valves to be simplified, greatly Improvement of maintenance work on valve
reducing maintenance effort. rotation device.

There is no need for the regular checks of valve rotation at Filing Advice
1,500 operating hours on the medium-speed four-stroke Assembly group/work card 113/114
engines in operation as per the engine type list opposite.

Measures
In future, the valve rotation will only be checked on these
engines in the following cases:

• Following disassembly/reassembly of the valve rotating

device

• After carrying out maintenance work or repairs on the

cylinder head

Work Sequence
The recommended work steps have also been changed.
The valve rotation check will now no longer be carried out
during operation with the valve cover open.

MAN Diesel SE PrimeServ PrimeServ PrimeServ

Head office (& postal address) After Sales Augsburg After Sales Technical After Sales Commercial
Stadtbachstraße 1 Stadtbachstraße 1 Stadtbachstraße 1 Stadtbachstraße 1
86153 Augsburg 86153 Augsburg 86153 Augsburg 86153 Augsburg
Germany Germany Germany Germany
Phone: +49 (0) 821 322 0 Phone: +49 (0) 821 322 3509 Phone: +49 (0) 821 322 1499 Phone: +49 (0) 821 322 1799
Fax: +49 (0) 821 322 3382 Fax: +49 (0) 821 322 1530 (24-h-hotline) (24-h-hotline)
mandiesel-de@mandiesel.com primeserv-aug@mandiesel.com Fax: +49 (0) 821 322 3838 Fax: +49 (0) 821 322 3574
www.mandiesel.com primeserv-aug-ae@mandiesel.com primeserv-aug-ac@mandiesel.com

MAN Diesel – a member of the MAN Group

DCI / No. 289 - March 2010

New Procedure
1. Preparation

Switch off the engine. Remove the cylinder head cover.

2. Colour marking

Make markings on the valve rotating devices and axial bearings.

3. Operation

Replace and secure the cylinder head cover. Start the engine and allow it to run for one minute at a
nominal speed with 25 % to 30 % power.

4. Check

Switch off the engine and remove the cylinder head cover. Check the markings. If the valve rotating
devices are working correctly, the markings will now be in a different position.

An exact description of the individual work steps can be found on the enclosed work card.

Important Note
It must be ensured that during the checking of the valve rotating devices, the engine cannot be started.

Contact
Should you have any queries, our Technical Service will be pleased to be of assistance:

MAN Diesel SE
86224 Augsburg
Tel.: +49 (0) 821 322-1401
Fax: +49 (0) 821 322-3838
E-mail: primeserv-aug-ae@mandiesel.com

Robert Glauber Jörn Holst

Senior Vice President Senior Manager
After Sales After Sales Technical

Please forward this information to your technical operational personnel and

remember to inform us of the current operating hours of your MAN Diesel engines.

Diesel Customer Information »Check of Valve Rotation« - Page 2 of 2

 MAN Diesel 113.02

Valve rotator

Inlet and exhaust valves

Checking rotating motion

Brief Description
Execute work on time according to the maintenance schedule, check com-
ponents for state/wear condition.
Valve rotators are to be assessed at regular intervals.
The work/working steps include:
Checking parts/components ,
Dismantling components ,
Assembly of components .
Required tools/auxiliary equipment
Quantity Designation Number Status
1 -Screwdriver (Set) - Inventory
1 Felt-tip pen/marker pen - Inventory
1 Lube oil, clean - Inventory

Corresponding work cards

Work card Work card Work card
113.01 113.03

Structure of the valve rotator

The base body (1) has several pockets arranged peripherally, in which the
balls (2) are pressed by tangential compression springs (6) to the upper end
of an inclined track. See Image 3. The plate spring (3) is located between
the main body and the cap (4) to which the valve spring forces apply. See
Image 1. The circlip (5) holds the rotator together when it is removed.

Work Cards, classified into assembly groups

Operating mode
When opening the valve, the plate spring (3) in the valve rotator is pressed
48/60B;48/60CR;L58/64CD;51/60DF
flat by the increasing force of the valve spring. The plate spring pressurises
the balls (2) in the pockets in the body (1) and compels them to roll down
their inclined track and itself rolls off on the balls. Support on the balls
reduces the pressure of the plate spring on the inside edge of the body (1),
which causes sliding here. The plate spring, cap (4) and valve springs are,
on the other hand, held together by friction to prevent rotation. The relative
rotation between plate spring/cap and base is transferred to the valve via
the body.
When the valve closes, the plate spring is relieved and also the balls, which
are then pushed back to their initial position without rolling by the com-
2009-07-15

pression spring (6).

6682 113.02-03 EN 1 (6)

113.02 MAN Diesel
Inlet and exhaust valves

1 Basic body 4 Cover

2 Ball 5 Circlip
3 Plate spring
Figure 1: Inlet valve rotator

Work sequence 1 - Checking the valve rotators

Starting position Engine at a standstill.

Work steps 1. Open cylinder head cover.

2. Make line markings on the valve rotators (15) and axial bearings (17) with
a felt-tip pen. See Fig. 2.
3. Close the cylinder head cover.
4. Start up the engine and run it for 1 minute at nominal speed and 25%
to 30% power output.
5. Shut down the engine.
Work Cards, classified into assembly groups

Danger of burning due to hot components!

Wear protective gloves during assembly work! Do not walk on hot
surfaces!
48/60B;48/60CR;L58/64CD;51/60DF

6. Open cylinder head cover.

7. Check the markings. If the valve rotators are working correctly, the
markings will now be in a different position. If the position of the mark-
ings has not changed, repeat work steps 3 and 4 again once.

Soiling in ball pockets!

Due to dirt, especially of the ball pockets from residues in the oil (due to
attrition, combustion products) there can be malfunctions. The
depositions stick to the individual parts and hinder the movement of the
2009-07-15

balls. The valve rotator must be removed, dismantled, washed carefully

and lubricated before reassembling. See work sequence 3.

2 (6) 6682 113.02-03 EN

 MAN Diesel 113.02

If the balls have been pressed in through concentrated load with a non-

Inlet and exhaust valves

rotating inlet and exhaust valve in the running surface, the complete
valve rotator or the thrust bearing must be replaced. Moreover, for non-
rotating inlet or exhaust valves, check the condition of the valve cone
and valve seat ring (see work card 113.03).

8. Close the cylinder head cover and fasten.

Work Cards, classified into assembly groups

48/60B;48/60CR;L58/64CD;51/60DF

8 Inlet valve seat ring 13 O-ring 18 Outlet valve cone with valve propeller
9 Cylinder head 14 Pressure spring 19 Exhaust valve seat ring
2009-07-15

10 Inlet valve cone 15 Valve rotator 20 Cylinder head cover

11 Valve guide 16 Valve cone piece (two-part)
12 Pressure spring 17 Axial bearing M Mark
Figure 2: Inlet and outlet valve

6682 113.02-03 EN 3 (6)

113.02 MAN Diesel

Work sequence 2 - Possible malfunctions and troubleshooting

Inlet and exhaust valves

1. Contamination, especially of the ball pockets, due to residues in the oil

(abrasion products, combustion products). The residues stick the indi-
vidual parts together and hamper the balls in their movement.
The rotator must be dismantled, carefully washed and oiled before re-
asembling. Refer to work sequence 3.
2. Major base torque as a result of the friction between control lever and
valve shank end or due to shank seals. If there is a major positional
skewing of the valve springs, the cover (4) itself may cause appreciable
moment of friction on the body (1), which brings the rotator to a halt.
The friction-generating parts or the valve springs must be replaced.

If the balls have been pressed into the tracks of the body due to point
load when the valve is not rotating, the complete valve rotator needs to
be replaced.

If an inlet valve has not rotated over a long period, check the state of the
valve taper and valve seat (refer to Work Card 113.03)!

Work sequence 3 - Separation and assembly of the valve rotator

Starting position Valve rotator disassembled (refer to Work Card 113.01) and place on sup-
port surface (circlip is at top).
Working steps 1. Remove circlip (5).

2. Remove cover (5) and plate spring (4) .

3. Remove all balls (2) and compression springs (6) from the body (1). See
Image 3.
Work Cards, classified into assembly groups

4. Wash all individual parts in suitable cleaning medium and then dry them.
5. Check individual parts for wear and ball impressions, renew if necessary
(for wear, refer to engine spare parts catalogue).
48/60B;48/60CR;L58/64CD;51/60DF

2009-07-15

1 Basic body
2 Ball
3 Plate spring
6 Compression spring
A Max. allowable wear = 0.1 mm
Figure 3: Limit of wear on the ball pocket tracks

4 (6) 6682 113.02-03 EN

 MAN Diesel 113.02

When changing parts of the valve rotator, the base body of the valve

Inlet and exhaust valves

rotator must be identified with the item No. of the used wear sets.

1. Place balls (2) and compression springs (6) in ball bag tracks.

Ensure that balls are at the highest point of the inclined ball pocket tracks
and thus all are in the same direction. See Image 3.

2. Insert plate spring (3), place cover (4) on top and install circlip (5).

The plate spring must rest with its inside edge on the base body. See
Image 1.

3. Place valve rotator in clean lubricating oil and remove shortly before
installation.

Never put grease in valve rotator!

Work sequence 4 - Assembly of the valve rotator

Starting position Valve rotator cleaned and oiled.

Assembly of the valve rotator - refer to Work Card 113.01.

Use only genuine valve springs, because only genuine valve springs will

Work Cards, classified into assembly groups

guarantee smooth functioning of the rotator.
48/60B;48/60CR;L58/64CD;51/60DF
Suspension Parts which are contaminated as a result of storage over a long period or
transport must be washed in suitable cleaning medium, dried and then
placed in clean lubricating oil for a few minutes.

Parts in stock must be stored well-packed, protected against dust,

water, humidity and aggressive media. Dust causes individual parts to
stick and prevents or hampers the rotation at the time of commissioning.
2009-07-15

6682 113.02-03 EN 5 (6)

113.02 MAN Diesel
Inlet and exhaust valves

1 Basic body 3 Plate spring

2 Ball 6 Compression spring
Figure 4: Ball tracks in the base body of the valve rotator
Work Cards, classified into assembly groups
48/60B;48/60CR;L58/64CD;51/60DF

2009-07-15

6 (6) 6682 113.02-03 EN