MAN 680Hp and 820Hp engines from the early 90's any problems other than the usual?

[Tender_aft]

I have 5 boats in my list (more on that when I have been to see them in a months time), 3 of them are DD engined (I have all the info I need on those and am thoroughly sold on them), and the other two are MAN engined. Of course, the boat has to be the "right" one, so I will end up with whatever engines come in the "right" boat.

I have researched these and it seems that they are pretty good (they were/are in Trent lifeboats), but parts and servicing can be expensive. Once I have taken a look at the boats in question, If I am interested still, I will get the serial numbers and ask MAN for the service history.

Does anybody have experience of the engines at these Hp ratings? any thoughts on what to look out for and parts/servicing/rebuild costs?

Thanks

 

[cryan]

MAN are pretty robust for the most part. I have known MANs of all sizes that have had issues with cam shafts and fuel pumps. Parts are easily available from the MAN depot in Stockport. I've been supplied by them for engines from the 1960's. MAN have been trying to bring all their official marine servicing in-house with the Primeserv brand. Primeserv is EXPENSIVE as its aimed squarely at the commercial market. One good thing about MAN though is that anyone can enrol on an engine specific course at their academies in Stockport or Augsberg. They're not cheap courses but well thought of. Where there have been some issues is when the engine is not an MAN one but actually a MAN badged version of an engine designed by one of the companies they swallowed up. I have seen a few high speed MAN engines at the powers you mention and have never known many defects. Those engines were all mechanical fuelling though so I can't speak for electronic fuelling. I presume DD is Detroit Diesels? I have always been a fan of Detroit Diesels. They are often used as emergency generators on large ships which I think shows the confidence people have in them.

 

[Tender_aft]

MAN are pretty robust for the most part. I have known MANs of all sizes that have had issues with cam shafts and fuel pumps. Parts are easily available from the MAN depot in Stockport. I've been supplied by them for engines from the 1960's. MAN have been trying to bring all their official marine servicing in-house with the Primeserv brand. Primeserv is EXPENSIVE as its aimed squarely at the commercial market. One good thing about MAN though is that anyone can enrol on an engine specific course at their academies in Stockport or Augsberg. They're not cheap courses but well thought of. Where there have been some issues is when the engine is not an MAN one but actually a MAN badged version of an engine designed by one of the companies they swallowed up. I have seen a few high speed MAN engines at the powers you mention and have never known many defects. Those engines were all mechanical fuelling though so I can't speak for electronic fuelling. I presume DD is Detroit Diesels? I have always been a fan of Detroit Diesels. They are often used as emergency generators on large ships which I think shows the confidence people have in them.

Thanks Cryan, I imagine MANs this age are mechanical fuelling, but I'll find out when I go and see them. Sounds like good news though.

(Yes DD is Detroit Diesels. Been talking and thinking about them so much recently, I've resorted to a minimalist acronym )

 

[Latestarter1]

You only mention power ratings not specific engine models however assume by 680 you are refering to the 2848 LE401 V8 680.

Unlike Cryan I would never describe MAN's as robust but my experience with them is mainly in rail applications, however the 2848 does the job provided that it is serviced absolutely by the book.

The A1 inspections due every other year
1 Check or replace injectors: evaluating opening pressure, tightness, and spray pattern.
2) Change valve caps on expansion tank
3) Clean: intercooler, charge-air pipes, turbos, and heat exchangers.

There is also a supplimentary A2 service every second A1 which involves change of coolant engine fuel supply and gearbox oil cooler hoses.

M5 Valve clearance checks and adjustments every 400 hours

Mechanical fuel system operating on the edge which works fine provided servicing is by the book.

There was an issue re the oil cooler housing, alloy changed out for cast iron, too lomg ago to remember.

If I was purchasing vessel with 2846 LE401 I would make 1,000 hr service conditional upon the sale as it is around £5K per motor.

 

[Tender_aft]

You only mention power ratings not specific engine models however assume by 680 you are refering to the 2848 LE401 V8 680.

Unlike Cryan I would never describe MAN's as robust but my experience with them is mainly in rail applications, however the 2848 does the job provided that it is serviced absolutely by the book.

The A1 inspections due every other year
1 Check or replace injectors: evaluating opening pressure, tightness, and spray pattern.
2) Change valve caps on expansion tank
3) Clean: intercooler, charge-air pipes, turbos, and heat exchangers.

There is also a supplimentary A2 service every second A1 which involves change of coolant engine fuel supply and gearbox oil cooler hoses.

M5 Valve clearance checks and adjustments every 400 hours

Mechanical fuel system operating on the edge which works fine provided servicing is by the book.

There was an issue re the oil cooler housing, alloy changed out for cast iron, too lomg ago to remember.

If I was purchasing vessel with 2846 LE401 I would make 1,000 hr service conditional upon the sale as it is around £5K per motor.

Thanks Latestarter, no mention of the models, as I don't know at this stage, I was hoping the HP rating and the age might give it away.

There isn't much info online; one thread in a US forum. I am well aware that there is probably more in boatdiesel.com, which I plan to join as soon as I am deeper than the preliminary search stages. I'm getting to the stage where I know a (very) little about all the engines that I may end up with, which makes it easier when yet another boat comes along. I didn't realize the journey to actually getting the boat would be quite as long. At this rate, by the time I get one, they will run off generators or solar

Edited to say, I just joined boatdiesel.com now, at last! with the model number you gave me, I can do some deeper research

 

[Deleted User YDKXO]

Unlike Cryan I would never describe MAN's as robust but my experience with them is mainly in rail applications, however the 2848 does the job provided that it is serviced absolutely by the book.

Hi LS1, don't want to be a pain but did you see my post from a couple of weeks back asking your opinion of the MAN D2840 LE403 engine (V10 1050hp)? Engines have done about 500hrs