B&W Cylinder Oil Feed Rate

MAN B&W Diesel A/S

Service Letter

No: SL90-261/OG February 1990

Recommendations for Cylinder Oil Feed Rate and Cylinder Oil Quality for VT2BF, K-EF, K/L-GF, K/LGFC/GFCA, L-GB/GBE Engines Dear Sirs, The following recommendations, which supersede recommendations given in Service Letters No. 81-161 of March 1981 and No. 83-196 of October 1983, are valid for engines installed in ships with controllable pitch and fixed pitch propellers as well as for stationary engines. Based on more recent service experience, our general recommendation can be summarized as follows: Specific cyl. oil feed rate:

VT2BF K-EF K-GF L-GF K-GFC L-GFC K-GFCA L-GFCA L-GB/GBE

= = = = = = = = =

0.5 - 0.75 0.75 g / BHPh ” ” ” ” ” ” ” ” ” ” 0.6 - 0.9 g / BHPh ” ” 0.6 - 0.9 g / BHPh

or or or or or or or or or

0.7 - 1.0 ” ” ” ” ” 0.8 - 1.2 ” 0.8 - 1.2

g / kWh ” ” ” ” ” g / kWh ” g / kWh

These figures are valid for catalogue MCR, i.e. catalogue output and for engines which have been run-in. Fig. 1 states the corresponding nominal feed rates in kg/cyl. per 24 hours for all the above engines on the basis of the catalogue MCR of the engines. PRODUCTION Teglholmsgade 35 DK-2450 Copenhagen SV Telephone: + 45 31 31 44 33 Telex: 19023 bwforw dk Telex: 19042 bwforw dk Telecopy: + 45 31 31 79 20

HEAD OFFICE (& postal FORWARDING & RECEIVING MAN DIESEL B&W SERVICE Diesel A/S address) Stamholmen 161 Teglholmsgade 35 Denmark Stamholmen 161 DK-2650 HvidovreSV DK-2450 Copenhagen Reg. DK2650Hvidovre(Copenhagen, No.: 24 231 (Copenhagen) Telephone: + 45 Telephone: + 45 31 49 25 01 Telephone: + 45 31 31 44 33 49 25bwforw 01 Telex: Telex:3119023 dk 16573,16592 Cables: manbandw Telex:dk16483 manpur Telex: 31197 manbw dk Telex:manbw 19042 dk bwforw dk Telecopy: + 45 Telecopy: + 45 31 31 5531 2249 20 Telecopy: + 45 31 49 43 97 66/4172

The figures have been slightly increased compared to currently stated figures, reflecting the use of fuel oils of an overall degraded quality and what has become common practice in the meantime. During start and manoeuvring and, preferably, during sudden load changes, it is recommended to increase the actual feed rate being used at the time. This can be done by moving the regulating lever on the cylinder lubricators at least two steps or simply to maximum position. We have detailed descriptions available on systems for automatical control. The oil dosage should also be increased if abnormal cylinder conditions are found when inspecting individual cylinders. The higher corrective dosage - normally 50% higher than the one applied - should be maintained until the cause has been found and rectified, and a satisfactory cylinder condition thus re-established. Feed Rate at Specified MCR and at Service Load The feed rate in kg/cyl. per 24h corresponding to a specified MCR different from the catalogue MCR can be calculated on the basis of the figures in Fig. 1, reduced in proportion to the mean effective pressure at that specified MCR as shown in Fig. 2, which is a speed/power diagram. Fig. 2 shows how to calculate the feed rate for two different specified MCR points Al and A2. If the actual service load of the engine is less than some 80% of any specified MCR, the feed rate in kg/cyl. per 24h can be further reduced in proportion to the actual mean effective pressure. This reduction is illustrated in Fig. 2 by the point A3, which is taken as an example on the cubic propeller curve through Al. By using calculations rather than the above graphical method, the new feed rate for the A3 point can be found by multiplying the old feed rate (for the Al point) with the square of the speed reduction ratio.

This calculation formula assumes the lower actual service load to be approx. on the same cubic propeller curve as shown by the example in the diagram by reducing power from the Al point to the A3 point. The speed reduction of the engine would reduce the calculated Al feed rate of 28.2 kg/cyl. per 24h to only some 24 kg/cyl. per 24h (28.2 x 0.85), whereas the reduction in proportion to the reduced mep will allow a further reduction to the calculated 20.3 kg/cyl. per 24h. For setting the cylinder lubricators of any particular engine, see the engine instruction book. In any event, the highest mean effective pressure that will occur in service should form the basis for the calculation and for the lubricator setting. Any service point should be inside the limits of the load diagram valid for the engine in question. It should be noted, with special reference to continuous low load operation, that the feed rate in kg/cyl. per 24 hours should never be allowed to drop below some 40% of the figure stated in Fig. 1. This means that for instance during canal passage, etc., the same precautions as are relevant during start and maneuvering, etc., ref. page 2, should be taken. Feed Rate for Breaking-in and Running-in The initial breaking-in of new liners is generally carried out using diesel oil or gas oil when a new engine is on testbed/trial trip. For breaking-in after overhaul of existing units, heavy fuel is usually used. The recommended schedule of cylinder oil feed rate adjustment on a time basis is shown in Fig. 3, both for breaking-in and the following running-in period. For the first approx. 24 hours of operation of new cylinder liners, i.e. the initial breaking-in period, whether it is a question of a new engine on testbed, or change of liners in service, or a piston overhaul where piston rings have been replaced, the oil dosage should be increased to maximum delivery by moving the regulating lever on the cylinder lubricator to the maximum position. The schedule of load increase during initial breaking-in after repair or overhaul should be as follows: Increase the engine speed to 80% in the course of the first 2-4 hours, and maintain this speed for 6 hours. After this 8-10 hours' running, the increase to full speed (power) is effected stepwise during the following 12-14 hours; giving a total breaking-in period of 20-24 hours.

Alternatively, if only one or two cylinders have been overhauled, the fuel pump index for the cylinder(s) in question can instead be decreased by at least 25%. The engine is then run up normally, and the indexes concerned increased slowly over a period of 20-24 hours. After these 20-24 hours of breaking-in with over-lubrication, it is recommended, as shown in the figure/ to use a running-in feed rate of not less than 25% above the one currently applied for about 1500 hrs, by placing the lubricator handle in the minimum position and adjusting the individual adjusting screws, after which a scavenge port inspection or liner measurement should be carried out. After this running-in period, the feed rate can be gradually reduced by the adjusting screws, if inspection through the scavenge air ports of the actual cylinder condition, or measurements of the cylinder diameters, warrant it. The reduction towards the lower feed rate, i.e. the rate at specified MCR or, in the special cases mentioned above, the rate at service load, should be carried out in steps not exceeding 0.05 g/BHPh at intervals of not less than 1000 h with thorough scavenge port inspections in between. In any case, the actual feed rate for a cylinder unit in service is to be based on an individual inspection of the actual cylinder condition through the scavenge air ports, rather than on figures stated for guidance purposes. This statement is also valid for the time scale in Fig. 3, where a shorter running-in period may be justified by a very good observed condition. As the ship's trade, maintenance principles, etc., vary from owner to owner, it is up to the customer to weigh the cost of lubricant against the cylinder liner wear rate and, on this basis, to judge which final feed rate is most suitable for his own individual requirements. Cylinder Oil Recommendations For operation on gas oil or diesel oil, a cylinder oil with viscosity SAE 50 and TBN (alkalinity expressed as total base number) 10-20 is recommended. An oil complying with these requirements is usually used on the trial trip. For operation on bunker fuel oil, a cylinder oil with viscosity SAE 50 and TBN 70 is recommended. On a trial trip it is customary to change to this type of cylinder oil when the fuel is changed from diesel oil to heavy fuel.

In most cases the high TBN cylinder lubricant will also be satisfactory, when operating on diesel oil/gas oil. Therefore, changing of the lubricant type to correspond to the fuel type used, i.e. bunker fuel or diesel oil/gas oil, is only considered relevant in cases where operation on the respective fuel type is expected to exceed 10 hrs. However, it should be noted that some of the high alkaline cylinder oils are not compatible with certain low sulphur fuels having poor combustion properties, and with some diesel oils. If any such incompatibility, indicated by poor cylinder condition, is revealed when inspecting through the scavenge ports, it may be advisable to use a cylinder oil with a lower TBN. Basically, it is recommended to consult with the oil supplier and engine builder before selecting oil types, but the attached list. Fig. 4, may be used as a guide. For convenience, also corresponding system oil types are mentioned. Some of the older engines already use a non-alkaline system oil, and it is not the intention with this Service Letter to suggest a change of such an established practice. Low-alkaline cylinder lubricants are available on request from the major lubricating oil suppliers. Yours faithfully, MAN B&W Diesel A/S

/MAN\

MAN B&W Diesel A/S Fig. 1 Cylinder Oil Consumption Nominal Cylinder Oil Feed Rate, ref. nominal rating

Engine Type

Мер bar

Power BHP/cyl.

Power kW/cyl.

Nom. Speed rev. /min.

Feed Rate kg/cyl. 24h

8.9 8.9 8.9 8.9 8.9 8.9

550 770 1140 1200 1650 2300

405 565 840 880 1220 1690

217 176 206 139 119 114

6.6 9.2 13.7 14.4 19.8 27.6

K42EF K62EF K74EF K84EF K98FF

10.7 10.0 10.0 10.0 10.5

620 1490 2090 2750 3800

455 1090 1540 2030 2800

227 155 134 121 103

7.4 17.9 25.1 33.0 45.6

K45GF K67GF K80GF K90GF K98GF

12.0 11.5 11.5 11.5 11.6

880 1870 2640 3410 4070

645 1380 1940 2510 3000

227 145 126 114 104

10.6 22.4 31.7 40.9 48.8

L45GF L55GF L67GF L80GF L90GF

12.0 12.0 11.6 11.5 11.6

880 1320 1870 2640 3410

645 985 1380 1940 2510

170 150 119 103 94

10.6 16.4 22.4 31.7 40.9

K45GFC K67GFC K80GFC K90GFC

12.0 12.0 12.0 12.0

880 1870 2640 3410

645 1380 1940 2510

L45GFC L67GFC L80GFC L90GFC

12.0 12.0 12.0 12.0

880 1870 2640 3410

645 1380 1940 2510

170 119 103 94

10.6 22.4 31.7 40.9

K45GFCA K67GFCA K80GFCA K90GFCA

13.0 13.0 13.0 13.0

985 2175 3060 3945

725 1600 2250 2900

234 150 130 117

14.2 31.3 44.1 56.8

L45GFCA L55GFCA L67GFCA L80GFCA L90GFCA

13.0 13.0 13.0 13.0 13.0

985 1500 2175 3060 3945

175 155 123 106 97

14.2 21.6 31.3 44.1 56.8

L45GBE L55GBE L67GBE L80GBE L90GBE

13.0 13.0 13.0 13.0 13.0

910 1390 2170 3060 3950

670 1020 1600 2250 2910

175 155 123 106 97

13.1 20.0 31.2 44.1 56.9

L45GB L55GB L67GB L80GB L90GB

15.0 15.0 15.0 15.0 15.0

1060 1620 2500 3530 4570

780 1190 1840 2600 3360

175 155 123 106 97

15.3 23.3 36.0 50.8 65.8

42VT2BF90 50VT2BF110 62VT2BF90 62VT2BF140 74VT2BF160 84VT2BF180

The feed rates are calculated on particular engines shown on page determined based on the observed the above. For running-in, use a 89.11.27 2600/OG/COS

725 1100 1600 2250 2900

227 145 126 114

10.6 22.4 31.7 40.9

the basis of the minimum for the 1. The actual feed rate, which is to be cylinder condition, may be up to 1.5 times feed rate of 1.5 times the above.

MAN B&W Diesel A/S Fig. 2, Calculating the Feed Rate

Example: L67GFCA Catalogue Power L11

Speed 2175 BHP/cyl.

mep

123 r/min

100%

Examples: A1

1960 BHP/cyl.

123 r/min

90%

A2

1740 BHP/cyl.

106 r/min

93%

A2

1200 BHP/cyl.

105 r/min

65%

Power/speed combination to be plotted in the diagram attached. Corresponding МЕР to be read in % of nominal on diagram to the left. Relevant feed rate A in kg/cyl. 24h to be calculated by multiplying read mep % with nominal feed rate An from Fig. 1. Catalogue Power; Аn x mep L1 = 31.3 x 1.0 = 31.3 kg/cyl. 24h = 0.6 g/BHPh Examples; A1 = Аn x mep1 % = 31.3 x 0.90 = 28.2 kg/cyl. 24h = 0.60 g/BHPh A1 = Аn x mep2 % = 31.3 x 0.93 = 29.1 kg/cyl. 24h = 0.70 g/BHPh Аз = Аn x mер3 % = 31.3 x 0.65 = 20.3 kg/cyl. 24h = 0.71 g/BHPh Appropriate service margin to be added (add up to 50%).

89.11.27 2600/OG/COS

Diagram for Feed Rate Calculation Ret. fig. 2

Fig. 3: Cylinder Oil Feed Rate Adjustment Running-in Schedule

Provided satisfactory cylinder condition is confirmed by scavenge port inspection, the cylinder oil feed rate may be reduced from maximum feed rate as shown by the shaded area. The actual final feed rate will with most heavy fuel oils and alkaline cylinder oils be within the recommended range from 0.5 - 0.75 g/BHPh and 0.6 - 0.9 g/BHPh, respectively. 4/1991087-B/1189

MAN B&W Diesel A/S

Fig. 4, Lubricating Oil Brands The list below indicates international brands of oil that have given satisfactory results when applied in our two-stroke low speed diesel engine types. The list must not be considered complete, and oil from other companies may be equally suitable. Further information can be obtained by contacting the engine builder or MAN B&W Diesel A/S, Copenhagen. Lubricating Oils Company ELF

System Oil SAE 30/TBN 5-9 Atlanta Marina D

Cylinder Oil SAE 50/TBN 70 Talusia XT 70

BP

Energol DL-MP 30

CLO 50-M

Castrol

Marine CDX 30

S/DZ 65

Chevron

Veritas 800 Marine

Delo Cyloil Spec

Exxon

Exxmar XA

Exxmar X70

Mobil

Mobilgard 300

Mobilgard 570

Shell

Melina S 30

Alexia 50

Texaco

Doro AR 30

Taro Special

89.11.27 2600/OG/COS