One MAN engine fails on last day end last trip of our summer holliday’s

[BartW]

B, I can see why a big power increase without affecting weight significantly might look appealing, but as they say, there's no such thing as a free lunch.
First of all, as I understand, we are talking of the same block, and it's easy to guess that an almost 40% power increase is bound to affect the reliability to some extent.
Secondly, I would stick RELIGIOUSLY to the suggestion from LS1 to not exceed the capacity of your existing transmissions.
Of which I know nothing ATM, but while trying to understand the MAN specs before getting in touch with those companies who are offering rebuilt 2842 engines, I came across this interesting table (see page 2):
http://www.demp.com/pdf/DEMP_PROPULSION.pdf
As you can see, the gearboxes recommended by MAN for your engine are either WVS 234 M or BW 165/A. Have you got one of these on BA?
Anyhow, the first of them is actually suggested also in combination with the 1200hp flavour of 2842 block, but for the 1300hp version, both the recommended gearboxes (WVS and BW) have a slightly different designation.
Now, unfortunately the 1500hp version of 2842 is not shown in the above table, but it's easy to guess that with 1500hp you should change also the gearboxes....
All subject to be checked with some MAN expert, of course.

good point P
I was not really aiming for more power, it was just that this pair of engines was offered to me,
and according the seller, the extra 2 turbo's operate at lower RPM, which is a nice feature at our slow cruising speed,
perhaps one can compare torque curves,

but now that we are at that,
the gearboxes I have are ZF type: BW165 P2
max power : 0.36Kw /RPM,
at 2300RPM, that is just over 1100Hp,

so these gearboxes are no go on these 1500Hp engines !!

 

[BartW]

Poor old Bart needs to find pair of similar engines which match the input capacity of his existing transmissions, have engines dyno tested and put it behind him.

Poor ? yes defintely when all these engine troubles are behind us
but Old ?? how can you say that

Repairing the broken engine, seems the best option now,
also taken in to account that we have limited choice when I want te re-use the old gearboxes, as you pointed out

just to give you a idea, I think I can reveal this, Ilko quoted 8000 euro, for all the work,
including everything that has been done so far, then re-assembling the complete engine, testing, lifting back in, re-installing, seatrials, etc...
may I say that this is a very good deal !?

(We're in Montenegro remember, just got a pricelist today from a yard next door,
they charge 30 euro /hr for general work on the boat, construction, painting, polishing, ...)

On the parts Ilko gave me some discount on his "official" prices, but even then, I believe they are still more expensive then in Central Europe, (had a few indications, but I'm waiting for exact prices from my suplier in Antwerp, for final reference)
if the difference is too big, I'll have a word with my MAN contacts in Germany and Zagreb !
I rather reserve some extra budget or a tip for the workers.

just as a reference about this company,
the day before yesterday we visited his workshop, and this is very clean, (forgot to make pics)
there were several disassembled engines in his workshop, they are working on, (Man, Volvo, and Cat)
One is a MAN engine from a police patrol boat we've seen many times this summer.
Unfortunately he doesn't have a dyno test setup.

 

[petem]

Any news Bart?

 

[BartW]

Any news Bart?

short update,

I have been offered quite a few pairs of rebuild engines from Italy and from Belgium,
most solutions didn't fit on the existing gearbox,
and had another "risc" factor and were more expensive.

then I've looked in to used spare parts for rebuilding the old engine,
but the financial benifit (including extra transport and handling) was not outweighing the extra reliability / warranty risc,
and a few technical details on the parts, send to me were not accurate / thrustworthy

so last weekend I gave Ilko my confirmation for the repair of my old engine, with all new parts:
ao, engineblock, crakshaft, camshaft, pistons (complete), liners, bearings, oilpump, injectors, one turbo, and many more bits and pieces......
so I'll have a almost new (zero hours) oldfashion mechanical engine. I prefer these instead of the modern comonrail versions.
the total project will cost me about 50% of a brand new modern engine

If all goes well, we will also rebuild the other engine (still running now) when the first is finalised

 

[Pinnacle]

Bart. Best of luck for the rebuild(s). Fingers crossed for you.

HNY!

 

[Mr Googler]

Hi Bart

Much better to deal with known quantities and people rather than gamble on anything used. I wish you the very best with it all and have no doubt 2015 will be a great boating year for you.

 

[Latestarter1]

short update,

I have been offered quite a few pairs of rebuild engines from Italy and from Belgium,
most solutions didn't fit on the existing gearbox,
and had another "risc" factor and were more expensive.

then I've looked in to used spare parts for rebuilding the old engine,
but the financial benifit (including extra transport and handling) was not outweighing the extra reliability / warranty risc,
and a few technical details on the parts, send to me were not accurate / thrustworthy

so last weekend I gave Ilko my confirmation for the repair of my old engine, with all new parts:
ao, engineblock, crakshaft, camshaft, pistons (complete), liners, bearings, oilpump, injectors, one turbo, and many more bits and pieces......
so I'll have a almost new (zero hours) oldfashion mechanical engine. I prefer these instead of the modern comonrail versions.
the total project will cost me about 50% of a brand new modern engine

If all goes well, we will also rebuild the other engine (still running now) when the first is finalised

Bart,

Probably best and most sensible solution, any replacement motors purchased complete would have had to have been stripped to install anyway.

I have just two observations.

#1 Not sure why a complete tear down of the running engine is considered necessary. Engine that failed was due to reliability reliability issue (damper failure) not a durability issue (wear out). Ignoring bearing thrust out damage a good assessment of engine general wear can be made by inspection of failed motor, this is not a commercial operation therefore engines were way short of life to overhaul. IF indicators as to general wear are good, my personal call would be to have the heads off the good motor and inspect bores before committing to a complete tear down. If bores good, personally I would have heads overhauled, reconditioned turbomachinery, new genuine MAN exchange injectors and a new crank damper checking of course end thrust is in spec, plus anything else your technicians recommend.

#2 Merely just my tenpennyworth, but what is is your blind side regarding later MAN's with common rail, they are smoother, quieter and fuel system and far more reliable than earlier PLI (Pump Line Injector) systems. Bosch PLI MANs were always on the brink towards the end with injectors having a pretty intense service regime. CR MANs are also far more sociable on cold start. Simply struggling with what there is to dislike?

Good luck and best wishes for the New Year!

 

[BartW]

#1 Not sure why a complete tear down of the running engine is considered necessary.

#2 but what is is your blind side regarding later MAN's with common rail,

1) Agree with you, didn't explain very well; but you need to know:
this running engine had 100% much more oil consumption then the broken engine, so therefor we agreed with Ilko, that this engine also need a thorrow inspection, heads off, ...
(we didn't go in to detail about this)
And after having seen the state of the liners & pistons on the first engine, I believe it makes sense to replace these on the second engine aswell, to have equal performance.
all your advice on this is much apreciated !

2) my blind side about modern MAN's is probably wrong and not objective,
and is caused by some opinions here on this forum
regulary there have been posts on here about reliability problems on MAN, and AFAIK this was alway's on common rail engines,
the last 4 years I've talked and questioned about this many times at many different occasions,
and also in Italy there was some mention about these issues among some boating people (not many)
in other area's they could not at all confirm about such issue's, ... (?)

then I own another boat with 2 x VP D3,(common rail) . We had a few issues with the engines,
and the frustrating thing about these engines is that the CPU just tell's you:
"go to the Volvo workshop"'
so many sensors / electric connections that can go wrong, etc...

in that respect, with a PLI engine, its much more easy to understand and see what is going on,
do some diagnose, and perhaps some small repairs myself

yes I know, all very "non" rational arguments
and for sure they are NO social engines,
but do admid, in a 23yo boat that isn't such a big deal, and the sound is great ;-)

best wishes to you !

 

[Deleted User YDKXO]

regulary there have been posts on here about reliability problems on MAN, and AFAIK this was alway's on common rail engines,

Please can we stop talking about the unreliability of common rail MAN V12 engines. You're making me very very nervous. Should I start saving up the cash to rebuild my engines right now?

This is a question for Latestarter1 really. I have checked my service manual for my D2842LE443 engines and there is no mention at all of checking the crank damper at any age or hours. Was this component modified on the common rail version of these engines or will the requirement to check this component only be stated in dealer documentation?

 

[Portofino]

Please can we stop talking about the unreliability of common rail MAN V12 engines. You're making me very very nervous. Should I start saving up the cash to rebuild my engines right now?

This is a question for Latestarter1 really. I have checked my service manual for my D2842LE443 engines and there is no mention at all of checking the crank damper at any age or hours. Was this component modified on the common rail version of these engines or will the requirement to check this component only be stated in dealer documentation?

Kinda +1 for LS re crank damper ? ------ do folks with in line 6 cylinder MAN,s need to worry ?
2876

Gut feeling is No

But I stress I run mine a low ish rpm. Wot is 2200 -I never really go above 1750= 32 knot s
Infact 1500 rpm is more like 26 knts more reasonable speed
I have 640 hrs recoreded .

 

[Hurricane]

Please can we stop talking about the unreliability of common rail MAN V12 engines. You're making me very very nervous. Should I start saving up the cash to rebuild my engines right now?

This is a question for Latestarter1 really. I have checked my service manual for my D2842LE443 engines and there is no mention at all of checking the crank damper at any age or hours. Was this component modified on the common rail version of these engines or will the requirement to check this component only be stated in dealer documentation?

Having seen Bart's problems on this thread, I'm starting to "set aside" some funds for a big service at 1000 hours.
Like you, I checked our MTU service manual and there is no mention of checking the crank damper.
Mine are V8s so maybe it isn't as vital as a straight engine.
However, checking the crank dampers will go on the list of jobs to do at that time.
It isn't that easy to get at that end of the engine in our installation and the belts will need replacing then anyway so that will be time to get some MTU specialists in.

Valve clearances are due then - that is something I COULD do but - I was in the MTU workshop, when they explained how to find TDC and I couldn't see the little flywheel mark even on the workshop engine.
If I was on my own, I think I would probably work out TDC from the firing sequence.
So, it seems to me that it would be well worthwhile getting some help at that time and some MTU experienced engineers to check it all out.

So, I have started to condition my mind to spending some money on extra engine preventative servicing at 1000 hours - stuff that isn't in the manuals/schedules.

 

[Latestarter1]

Crank damper inspection is a generic thing, however many manufacturers fail to publish specific service inspection criteria, for example there was an outbreak of panic with some Australian boaters over Yanmar LP crankshaft failures and an hours based replacement schedule was discovered in the small print.

Certainly not confined to MAN regardless of engine colour harmonic damper inspection normal good practice. Any inline 6 or V12 will have at least two periods of critical torsional activity one lays in the normal operating range the other which is the potentially destructive one is always outside the operational envelope for obvious reasons. One never wants crankshaft critical either at rated rpm or torque peak.

The location and severity of torsional period in the operating range is part of any manufacturers 'Crown Jewels', I often look at size and type of damper on a specific engine and think they have had problems taming that sucker!

Two types of damper, the bonded, where the weighted outer element is bonded to the inner element with an elastomer. Visual sign of distress is simple as the elastomer will either bulge or start to break up. There is also a check to ensure continuity of bonding, with two engraved marks on inner and outer elements which must be in line.

Viscous dampers have silicone entrapped within them which passes through passages restricting the flow creating damping effect. Visual inspection of this type of damper is also simple, when it fails it simply swells up, also shows signs becoming hot.

When I was at sea a Daisy Doxford in ship I served used to have real nasty torsional, 92/95 rpm or something around that. Full away was 110 rpm, once punching into a big sea fully loaded was pulling us back into area of torsional activity causing paint to bubble on the damper cover, pulling the fuel back to get under the torsional caused grief from the Old Man and the Chief would go loopy about spoiled paint finish in his spotless engine room just prior inspection by Marine Superintendent on our return to the UK.

Sadly we have Volvo Penta to thank for peoples conception of common rail engines. I work with CAT ET and Cummins INSITE electronic tools both are super, once you open a job any faults are downloaded, simple trouble shooting tree to fix any active issue and you cannot close the job until all faults are fixed. The customer gets a copy of the job sheet which calculates the number of chargeable hours technician SHOULD have taken to fix the issue, am aware that this feature is not at all popular in Italy! I am certain equivalent Detroit/MTU and MAN tools are equally good.

Happy new year......

 

[rafiki_]

Useful stuff LS as ever. Any idea what the first harmonic revs are on the Cat 3126?

 

[MapisM]

Useful stuff LS as ever.

+1.
I'd love to know also the 3116 rpm, if different from 3126.
...though I suspect that the poor LS1 could soon be overwhelmed by such request for each and every engine models around....

 

[MapisM]

Please can we stop talking about the unreliability of common rail MAN V12 engines. You're making me very very nervous. Should I start saving up the cash to rebuild my engines right now?

LOL, naaah, in your boots I'd rather return to Ameglia in a couple of years, as leave the boat to them as a p/x for a Sanlorenzo, passing the potential problem to someone else.
That's a much better reason to start saving, I reckon!

 

[Deleted User YDKXO]

Two types of damper, the bonded, where the weighted outer element is bonded to the inner element with an elastomer. Visual sign of distress is simple as the elastomer will either bulge or start to break up. There is also a check to ensure continuity of bonding, with two engraved marks on inner and outer elements which must be in line.

Thanks LS1, thats really useful. I've just checked the parts manual for my engines and the vibration damper looks very similar to Bart's engine, not surprisingly, so I'll definitely be checking them both out this winter

 

[Portofino]

Thx from me LS1 -

http://en.m.wikipedia.org/wiki/Harmonic_damper

 

[Latestarter1]

From posting re Onan generator it appears that there is a bit of misconception re torsional vibration. Bart's vibration at point of failure was likely the result of damper ceasing to function, once the crank bearing thrusts had been taken out crank moved forwards due to thrust from helical timing gears and crank pins no longer in line with piston wrist pins not to mention failed main bearings, all causing engine to rumble and vibrate like hell.

Important point just to prevent any paranoia, is that you will never sense your engines torsional period (vibration) and it is all being looked after by the crank damper, or dampner as out North American friends insist on calling it.

Engine rotation is not truly synchronous during a cycle as is reached TDC crankshaft slows down, after TDC speed increases again which has the effect of imparting a twisting motion on the crankshaft. Crankshaft has its own torsional frequency when the effect of reciprocating masses and cranks natural frequency are close together this is the torsional critical period. The damper is simply a rotating mass which is elastic allowing the mass to very slightly lag changes in engines rotational speed damping out the twisting effect. Important factor is the length of an engine crankshaft, the longer the crank the greater the amplitude of the twisting effect furthest from the flywheel.

The Packard V12 gasoline engines fitted to U.S. Navy PT boats used to be subject to catastrophic crankshaft failures when pushed to high output. In order to resolve the problem later versions of the engine employed 'fork and blade' connecting rod big ends rather than side by side, allowing a shorter crankshaft journal changing the natural frequency of the crankshaft. What Packard never knew was that crews regularly wired the governors open, allowing motors to run 'pedal to the metal' which was actual cause of the failure.

The only time any owner will ever be aware of the effect of this changing engine speed is at idle when an ill matched gearbox drive coupling allows transmission to sense the speed variation causing transmission gears to talk to each other 'chatter'. This is what is being referred to when 'torsional compatibility' is mentioned in warranty documents.

Rest easy

 

[BartW]

Thanks LS1 for all these clarifications, much apreciated !!

some more info and details about my broken damper;
From the first moment, Ilko ( our local MAN service man) thought that there must have been a cause for the breaking of the damper;
some unwanted unnormal vibration,... ?
he and his colleague were very persistent on that,
He suspected wear or unbalance in the injection pump, causing unbalanced injections / explosions
after opening the engine, He noticed that the cranc had been disassembled previously, and had been worked on.
He also found a little "unballance" on the camshaft gear (0.4mm out of centric)

last week I met Alfonso, who was many years (before me) the captain on Blue Angel. He confirmed that the engine had been opened, and the crankshaft had been replaced, one or two year before I purchased the boat. The reason he told me was that a "screw has come loose inside the engine" and caused a terrible noice/unballance
That work was done by a certified MAN man in Rome, (I know the man, and he has a thursworthy reputation)
We 'ill probably never know exactly if this added to the braking of my vibration damper, ...

the least I can say is, that this damper was 23 years old, and that after many warming and cooling cycles, and forces on the damper, that there might have been a weak part in the fairly thin mounting flange.

I have found a original maintenance scedule for this engine in the boats old paperwork,
and there is nowhere mentioning about a damper inspection, nor preventive replacement.
perhaps LS1 can clarifie what's normal practice.

To Deleted User, (and other concerned boat owners)
In your case, I think your chances to face such a problem are almost zero,
your crancshaft is shorter, (as clarified by LS1),
much less engine hours,
and most of all; many years younger

the lesson I have learned is:
with any vibration on the engine, stop the engine immediately, and have a specialist looking at it.
I can say that I've alway's been cautious with the engine, checking oil and coolant levels, loose items, etc…
I have a IR measurement tool that I use frequently to compare the temperatures on different spots of both engines.
We didn’t have MAN people doing service on the engines, because I've alway's feared a ripp off; they send a assistant or unexperienced trainee for the servicing, and you pay a unreasonable bill.
In SOF there was just a lack of service people I could thrust.
The good thing where I'm am right now is that during the last few months, I had the chance to build up a relation of Mutual respect and understanding with the local MAN man.

 

[Hardmy]

Bonsoir Bart, I am following your post with lots of apprehension. I cannot contribute to this thread in any way, apart crossing fingers and holding my thumbs for you. The most important is, that your cruising 2015 won't be amputated because of all this. Best, V.