Page 1 of 2

Common Rail Engine 48/60 cr

Posted: Thu Jul 20, 2017 10:33 am
by TDC
Good Day ,
I am a long time guest of this site and would like to thank Martin for this excellent resource for both professional and leisure activities he is facilitating. Finally I decided to register and post as I am seeking some discussion on the MAN 48/60 CR engine.
I am currently experiencing a shit load of issues with the common rail system components. High pressure pumps, injectors , control valves, throttle valves , magnets all of which barley making 50% of the service life hours. Not to mention while not part of the CR fuel system every cylinder on both engines had cracked land rings .I strongly believe there is an issue with this design but of course MAN are being no so forthcoming. Any of you out there experience any similar issues? . If so I would much appreciate the opportunity to discuss further.
Thanks
TDC
Remember an alternative definition for Marine Engineer is " Person which makes the Skipper look good"

Re: Common Rail Engine 48/60 cr

Posted: Thu Jul 20, 2017 10:37 am
by TDC
And yes I know it should under the workshop thread LOL

Re: Common Rail Engine 48/60 cr

Posted: Mon Jul 24, 2017 4:24 am
by JK
you will get more response above. If you wanted it moved I will, but I suspect you have a reason.

Re: Common Rail Engine 48/60 cr

Posted: Mon Jul 24, 2017 7:43 am
by TDC
Yes please move , I thought for some reason that more people would see it if I put it there. Guess I out smarted myself on this one.
Thanks

Re: Common Rail Engine 48/60 cr

Posted: Tue Jul 25, 2017 7:47 am
by Big Pete
Sorry no experience with this engine. I guess a lot of the problems might be due to fuel or lack of cleanliness in the assembly and flushing through of the fuel system when it was commissioned, so it might get better with time. However, the days when MAN engines were built in Augsberg, Germany are long gone. All the parts will be built in China, and maybe you have ended up with substandard parts in your engine. The makers will never admit anything. The only chance is for the shipowners to talk with each other and collectively prove that they have been sold rubbish engines and take a Class Action against MAN, or at least threaten to.
Good luck with this one, it sounds like a pile of junk.

BP

Re: Common Rail Engine 48/60 cr

Posted: Tue Jul 25, 2017 11:43 am
by Merlyn
Sounds like a Monday morning manufacturing jobby or a POETS day one.

Re: Common Rail Engine 48/60 cr

Posted: Fri Jul 28, 2017 4:53 am
by Atlantic
I would look in to the fuel supply system. Is the purifier set up for the right fuel viscosity. Are the fuel filter the recommended type micron etc.

Re: Common Rail Engine 48/60 cr

Posted: Fri Jul 28, 2017 7:11 am
by Big Pete
Atlantic has a point there, another think to look for that I have seen, is that some "Engineer" has found it difficult to compress the springs when installing cartridge filters and has thrown the springs away, because they did not consider them to be neccessary! Of course if you do that the filter element just floats around freely inside the housing and the oil just bypasses it, you have to have the spring correctly installed so the filter element is pushed against the head of the filter assembly to make an oil tight seal between the inlet and outlet of the filter.
Another thing to look for is that OEM filters will usually include a set of replacement seals and gaskets, AND THEY ARE THERE TO BE USED, Grey Market spares don't as it helps to keep the cost down, but the filter is useless if the seals are leaking internally.

BP

Re: Common Rail Engine 48/60 cr

Posted: Mon Jul 31, 2017 8:15 am
by TDC
Thanks BP and Atlantic for your responses. Basically the filter system is as MAN spec. its 10 mic before the fuel module and 25 mic before engine inlet. MAN have recommend an additional 10 mic after the fuel module however through our own research we discovered that a vessel trading overseas with the same engine had almost the exact same issues happening at the same running hours. MAN were involved in proposing a filter to this vessel and in the end it was found not to help. Which makes it double frustrating , that with this known then still recommend the same to us, and aft 50 k of expense between purchase and install they already have some evidence that this is not the answer. We have drilled the crew to be extra cautious with the cleaning and changing of the duplex 25 mic as per BP, and were are presently looking into the possibility that the purifier may not be eliminating some catfines to meet the 15 ppm engine inlet spec. We also have made contact with various companies with these engines , non of the feed back was positive to date. One company went as far to lower the change out interval on the fuel pumps to 4000hs just to avoid failure while in operation while another company informed us they switched to MDO and ULSFO and the performance was worse. Perhaps ensuring a cleaner fuel supply will improve the situation but I am leaning towards that there is design issues with this system. I hope we will find the purifier is not doing its job but the evidence in my mind is pointing to a much bigger issue.
Once again thanks for the replies ,
Ed

Re: Common Rail Engine 48/60 cr

Posted: Tue Aug 01, 2017 8:21 am
by Big Pete
Glad to help, it sounds strange to have finer filtration before the fuel module than after! After all the filters before the fuel module are to protect the fuel booster pumps which are pretty tough when compared to the fuel injection pumps that are protected by the engine filters.

Very hard to get Catalytic Fines out of fuel oil, they are sponge like pieces of hard Ceramic Material coated in Vanadium Pentoxide or Platinum in order to Catalyticaly Crack those big old, viscous long chain molecules of bitumen into smaller, less viscous molecules that are more burnable and valuable.
They have a large amount of oil trapped inside their sponge like structure, so their Density is virtually the same as the oil they are in, only way to remove them is fine filters.

Have you had any of the failed components examined microscopically? I am wondering if they were surface hardened/ Nitrided or something similar, and the surface layer is losing adhesion to the base metal due to fatigue failure, it may be a heat treatment issue, once you get fragments entering the fuel system AFTER the filters, you are screwed.

BP

Re: Common Rail Engine 48/60 cr

Posted: Thu Aug 03, 2017 1:17 am
by Merlyn
I think personally BP and Atlantic's comments re fuel contamination / missfuelling could well be where the problem originates from.
I have experienced horrendous CR problems over the inability of the lubricant in the fueloil to prevent/ delay the advanced wear on pumps and injectors owing to the dilution of the fueloil by a liquid which has removed the lube factor to such an extent like you would never believe.
On early CR courses in the eighties I went on we were shown the stripped results of fueloil contamination of both HFO and LFO installations, HP and LP pumps roller bearings stripped out of both inner and outer bearing tracks displayed on the actual rollers themselves flats which rather gave you the impression that they had been held against a turning grinding wheel such was the extent of the size of the flats.
Stripped CR injectors displayed score marks like the railway tracks in a damaged liner.
Without the fuel lubricant being present to lube all surfaces it was like metal to metal through the whole of the fuel system.
The course instructor stated that the correct way to address this situation was to steamclean the tank and replace all fuelines, filter housings, pumps, any accumulators ( if fitted ) HP /LP ( if fitted ) pumps, all injector pipes and of course all injectors together with any fuel sender sensors/pressure gauges etc fitted.
In other words everything contaminated by the lack of lube not present had to be replaced.
I have had many situations whereby fuel contamination has damaged injectors beyond repair ( new nozzles/pintles etc ) and we have stripped the CR injectors for interest purposes before renewal of same without changing the HP pumps only for the engine to break down again shortly afterwards with the newly fitted injectors beyond repair yet again together with HP/LP pumps.
In other words an on going nightmare all round and when you are doing someone else's engine you have to cover your back big time to avoid any " since you remarks "
The safest way obviously is to run scared and do what you were told way back when on the CR courses.
In other words renew every thing in the fuel system.
Back then even the instructors had not encountered problems that we had with CR systems on different makes/ types of engines.
We also had several engines with piston damage present which gives me food for thought over your remark concerning " lands " by which I take it you mean the piston lands, i.e. The areas each side of the ring contact with the piston.
Seems to marry up perhaps with lack of lube faults in the fueloil which seems far worst in CR set ups versus the original mechanical injection systems we all were brought up on.
On a lot of engines any collapse of pressure in the fuel rail would instigate an instant shutdown of the system via the pressure sensor mounted in the rail / hp pump body/ lines.
Don't know if you have any record of miss fuelling / bad fuel/ filtration systems logged anywhere that might give you a clue to how the fuel system has aged well before it's time?
What with the fuel system components and the piston " lands " damage it all seems perhaps to add up maybe?
Of course we have to remember that the lack of lubricant present in the fueloil pays no respect to make, model or type of any engine so Mr MAN maybe not guilty on this occasion?
I would have to say that nearly always the LFO setups predominate this self destruct by lube oil absence present in the fuel but perhaps you could do the research re old logs/ crewmembers as to whether the ship has ever been Miss fuelled/ diluted by any substances which can remove partially the necessary lube for all injection equipment.
There are a lot of those MAN 48/60 type engines out there operating quite satisfactorily so unless your ship is like the old Northern Star ( continual breakdowns and scrapped at a very early age through machinery problems ) or the QE2's turbines problems maybe the fuel side is where to look as the components you have said were damaged together with the piston land damage do in my option equate possibly to lack of lube in the fueloil.
Just a thought.

Re: Common Rail Engine 48/60 cr

Posted: Thu Aug 03, 2017 4:31 am
by D Winsor
I've been doing some searching around in an effort to see if there were similar issues in the automotive/trucking industry now that high pressure direct injection CR fuel systems are becoming more common in both diesel and gasoline engines. What I found is that indeed similar issues have occurred and from what I've learned it has been determined that the primary culprit for fuel system damage, similar to what TDC has described, was good old H2O. The industry found that water down to the molecular level, at pressures high enough for injection atomization, when not held in suspension or removed by other means caused major surface damage to high pressure components. In that industry the response has been to either to add emulsifiers or de-mulsifiers either as part of the refining process or directly into fuel tanks almost eliminating issues that resulted in damage to high pressure fuel components.

Back in the day when I first started working with heavy fuels it was common practice to run the fuel through both purifier & clarifyer to remove as much water and contaminants from the fuel. However in more recent years as purifier technology improved it seems more often than not clarifiers are either no longer fitted as part of the fuel purification system or have been bypassed.

Where it is highly unlikely that emulsifiers or de-mulsifiers are added to especially Marine Residual Fuels during the refining process and water in fuel has always been an issue on ships. I'm inclined to believe either adding or injecting an emulsifier or de-mulsifier chemical directly into the fuel system, either in the day tank or at the suction from the day tank, or clarifying the fuel after purification could help reduce or eliminate some of these issues.

Re: Common Rail Engine 48/60 cr

Posted: Thu Aug 03, 2017 7:54 am
by Big Pete
Interesting that I interpreted the original report of "Not to mention while not part of the CR fuel system every cylinder on both engines had cracked land rings" as being the Entablature Lands that the liner sits on, Merlyn interprets that as "We also had several engines with piston damage present which gives me food for thought over your remark concerning " lands " by which I take it you mean the piston lands, i.e. The areas each side of the ring contact with the piston." Just shows that every reader will produce a slightly different interpretations of the written word.
I agree with D. Winsor that it could be a water problem, in which case keep the settling and service Tanks hotter for longer, drain them regularly and also any other drains in the system. ( in the past I have found water to accumulate in the bottom of filters and replaced the drain plugs with a drain cock which can remove a surprising amount of water.) and make sure the purifier is set up right, if you have 2 purifiers run them both, either in series or in parallel but always at the slowest flow rate that will keep the service tank full.

A problem I had on one ship was that the HFO booster pumps were continually getting trashed, I found that someone had been putting fine filters on the suction side of the pumps, but because the ship had been changed to a heavier grade of F.O., they dropped the suction pressure at the pump inlet causing the fuel to boil and cause cavitation damage.Water accumulating in the bottom of the filter housing aggravated the problem.
The original design had called for course filters at the suction of the booster pump to protect them from damage and fine filters afterwards to protect the fuel injection equipment. A previous Chief Engineer and Super had decided that rather than ordering 2 different Micron filters, they would order all the same Micron rating, the average of the 2 original filters. As a result the booster pumps were trashed by cavitation and the Injection pumps by the large particles going through the filters.

Good Luck.
BP

Re: Common Rail Engine 48/60 cr

Posted: Thu Aug 03, 2017 10:45 am
by D Winsor
BP You're correct cavitation could also be a contributing factor.

When I was on ships set up with a Clarifier, the primary purifier with a typical oil to water interface fed the clarifier. The clarifier while not having any kind of sealing water was effective in catching water or other contaminants carried over from the purifier while reducing the risk of water carryover from any emulsion at the oil/water interface in the purifier.

I'm not a chemist but I think this problem may also be connected to and an unintended result of the removal of sulphur from the fuel. With the sulphur reduced or eliminated from the fuel there may be few if any other compounds or elements in the fuel that water will readily bind with at the molecular level and help keep it in suspension at high pressures and has led to the use of emulsifier fuel additives to compensate.

With respect to damage to the piston lands. I think that this could be the direct result of the injection control computer constantly changing the injection timing in order to correct and compensate for irregular and or erratic combustion and misfires caused by or resulting from the damage to the fuel system components.

Re: Common Rail Engine 48/60 cr

Posted: Thu Aug 03, 2017 5:23 pm
by Revolver
-How old is the ship/engine
-Do you know the conditions of your fuel tanks
-Where did you get your fuel
I assume your bunker delivery note(s) was (were) all to ordered specifications

-and like everyone else said; your purifier(s), they have their own array of investigations/questions


Other than that, how goes the investigation?