Man 2848LE 800HP V8

There is not an easy answer here.
All MAN service schedules kept, never overheated, better engine oil and coolant, average loading, wrong propeller loading and amount of fuel consumed means a lot to life long hours on any engine.
You will need perfect records to prove these service points were up.
MAN parts and service is expensive and sadly, some to lots of service items get skipped or cheapened.

That was a great engine, now 900hp and still getting over 4000 hours.

Perfectly serviced mechanical injected 800 Man V8's could see over 6000 hours.
However, because of it's age in years, 4500 to 5000 max, IMO.

Then, some engines were called MAN-grenade for a reason.
I feel this forum (YF) likes MANs and this nic-name was developed from poorly installed or serviced MAN engines.

If you are considering a MAN powered boat, Find a real MAN shop close by.
Go check them out. It will be a shop like this that helps the life of your MAN engines.

I think Cabo47 is referring to his own engines? In the early 1990's, I think it was, Man had a problem with piston heads disintegrating. They honored all warranty work and fixed the problem fairly quickly. I think they even swapped out pistons in the affected existing engines.

Sorry if I was wrong. Questions like his (IMO) usually come from shoppers.
Also Cab047 stated early 2000 engines. Was there piston problems then also?

Beau, You have the V12 version of this engine if I recall correctly? Long life?

I think the problem was isolated to the early 1990's Maybe someone with more knowledge can corral that better.

I have the 10 cylinder 820's; a solid workhorse. Runs all day at generator rpm

I believe it was 1996-97. Two guys in a marina I was running at the time blew their motors on their south runs. Mann fixed on and replaced motor on the other.

There was a batch of faulty Bosch injectors around that time .
A certain number hosed fuel [ stuck open ] and pistons melted with catastrophic results, before a MAN managed to recall and replace enough in the field .
But that’s nearly 20 y ago or so .Any faulty ones will have been replaced by now .How ever the nick name lingers on .

Yes, it was. I remember the protests at the FLIBS that year, lots of angry customers came out to recommend some action by the company.

I think I was incorrect, seems that he is referring to a 50' which would not be his Cabo....

They were the 1050 hp 10 cylinder MANs that were the ones that had big issues, melting pistons and such.

as for the 800's......6,000 hours +/- …….I know an owner of a 50' Post with the 10 cyl 820's and has just under 7,000 hours without rebuilds.

I wish I knew the answer to your question, because those engines are exactly the ones running my own boat.
2004 vintage, about 16 hundreds hours clocked, so far so good.
And if they'll last as much as Capt Ralph predicted, they'll outlive me, so I'll take his estimate!

FWIW, I did a bit of homework before buying the boat, and I found a rather widespread consensus about the fact that they were among the more robust engines of their era and in that power node, together with the Cat 3406.
They are in fact the very last of the fully mechanical MANs, with no electronics of any kind.
Essentially the same technology of the V10/820 that Beau has in his boat, but when the V8/800 was released in the second half of the 90s, as an upgrade from the previous 680hp, it overlapped the V10/820 in a lighter package, so they upped the V10 to a semi-electronic 1050hp, and then to the common rail 1100hp, before eventually phasing out the V10 block completely.

A somewhat folkloristic story is the reason why MAN kept building the V8/800 for a few years after they released the common rail V8/900, i.e. up to 2006, as I recall: it was their only engine in that power segment approved for installation in boats built to classification society standards.
In fact, not only the newer V8/900 CRM, but also their inline 6 (available as 700hp semi-electronic and 800hp CRM) did not tick that box.
Now, you can make of that what you will, obviously. It certainly doesn't imply that the other engines were bad.
Anyway, it's kind of reassuring that the older technology was trusted more than the newer one.
But I'm saying this with my fingers firmly crossed!

Should you be interested in more details, just specify.
I know my chicken reasonably well, by now.

Like the bomb proof 3406, The MAN R6s should also prove bomb proof.
One rod bearing per crank bearing keeps that crank shaft straight and powerful.
That's why 6 cly motors can make more reliable HP per lung than V blocks.

You remember the ole Hornet in line 8? Blown it made the most HP per lung in gas engines.

I remembered as a hand in crew, a new MAN (V10s?) boat heading down the StJohns river later 80s from Bronson Lambs yard. Every minute of running, the more block vent smoke came out. When we made back to the dock, both engines died (suspect sized).
They were pulled thru the night and never talked about again. 2 weeks later, that same boat was screaming down the river and never came back.
Bronson never would fill me in on the whole story. Scuttle was new blocks were flown in and fixed all issues in a couple of days.
I had always kept reservations about working on them for a long while. Then SeaRay started selling them.
Fast Forward 20 years, I'm servicing them and crawling all around them. They sling oil as a good Detroit but fixable.
Freaking DanFoss sensors are expensive POS's. Never could cross a Nason sender to them. But, I stayed busy.

You can follow all of my YF threads on MANs I have posted. You need a heavy tech in your area. None (worth a ship) are in this area.
Thru the early days, Performance Diesel in Texas, I guess felt sorry for me; sent manuals and parts and answered all my phone calls.
Great guys. We both kept the customers happy.

Here in the swamp, most of those boats have headed back south and Detroit and old Cummins are the norm.
The big MAN issues these days are refinishing the valve cover caps.
Yep, I'm sure they fixed their issues. You still need bux to deal with scheduled items and these POS senders. Oh, Main logic boards cant remember hours on the later high tech stuff.

I rarely see sensor issues on Man's now. The sensors have gotten a lot better. I remember doing an engine startup on a brand new cabo with MAN CR 900's.....on startup one sensor the port engine alarmed, so they ran and got a new one. On the way in from the seatrial ANOTHER sender on the port engine went bad. The 1100 HP CR v10's are very good engines. I run a set of the new 1200 HP v8's and they don't have nearly the torque the 10's did. I haven't seen any issues with the new MANs lately. Here and there a few things......had a gasket leak raw water onto a turbo bypass valve/wastegate and MAN came out and fixed it ASAP.

Yeah most inline 6's are a beast and reliable......like the C18......

Been running the 2876 In line 6 @700 Hp for the past 5 years from 480 to 880 hrs and zilch issues , yup zilch .
Fresh MAN spec oil and filters annually only .
Tend to cruise at 80 % load ....in-fact I use that handy parameter on the screens a lot along with the EGT gauges .
I did the valve lash myself with the help of a mate just a few exhaust valves were out .Pretty easy engines to work on .I think that’s a 400 hr interval ?

Yes the gold valve caps have pitted on the exterior , but are immaculate on the inside .....if you remove them and peek under .

They seem well engineered compared to the previous VP KAD 300 motors .Particularly like the zero use of pencil anodes .
Like MAN s transom / hull anode system along with the engines electrics isolated from the rest of the boat .
No corrosion what so ever of any components, or likely to be as long as the huge anodes are connected by the earthing strap to the block .unlike the VP engines .

Rarely go over 1800 rpm ( WOT 2200) mindful of there age 2003 .

So it helps interns of longevity of let’s face it old engines to be sympathetic to them imho , which I guess depends on the instal where they up to the job when new ?

Sensors .

Not had any fail yet .But there’s a few ( or were before my ownership) that look new none OEM .They have red Danfoss labels on .The OEM are painted white .

So you can get the identical part from a danfoss dealer not MAN

I have found a U.K. supplier ready , as pre purchase research did indeed suggested they are the Achilles heal of MANs

Look like £150 for a pressure sensor so to me seems not unreasonable every now and again in the bigger scale of running a boat ??

They ship WW
https://www.mandmcontrols.com/danfoss-pressure-controls/danfoss-pressure-switches-single

I see your point ref. main bearings in principle, but output also depends on manufacturers' choices, to a large extent.

At this size, Cat and also FPT have always been focused on inline engines, but the Germans not so much.
As I recall, MTU never had any inline engines in their lineup, and also among MAN engines, actually their Vs always had a higher specific output, compared to the inline 6.
Obviously, we must take models of the same vintage, in order to make a meaningful comparison.
Back in the V8/800 days, their most powerful inline 6 was the 700 (aka D2876LE401 - the "R6" label came a bit later, with the 730 and 800).
And in spite of the fact that the V8/800 was still mechanical and the I6/700 had an electronic governor, the specific output was higher for the V8 engine, even if just by a hair (54.7 hp/liter vs. 54.6).
In fact, as one of the older MAN dealers told me, they introduced the inline 6 mainly as an alternative for installation in not very beamy boats, where the V8 width could be problematic.
In the following years, they invested even more on V engines, as in you can check in their latest lineup, all fully electronic and CR, where the differences went ballistic.
The specific output reached 80 hp/l for the V8 (and 83 for the V12!), while their more powerful I6 still delivers "only" 68 hp/l.

Not that I'm a fan of high specific output, mind.
Rather the opposite: in a boat, I rate durability well above weight/performance ratio.
Just saying, along the lines of your thoughts...

When I was beginning my search 4 years ago I was told by a few people in the industry that the 1050 MAN's were an engine to be cautious of. Part of my usage is trolling for salmon and I was highly encouraged to go common rail as they idle better I was told. I absolutely love my R6's and the new I6 is now being offered in 850hp and I have been told several improvements were made over an already well regarded R6 model.
As for the mechanical 800's the OP is asking about I have heard they are good motors and like was early said if maintained no reason not to see 5k plus.

I think you may be "lugging" at 2200? Most of us try to keep WOT at 2350 for a load margin

I have always recommended just an extra few more rpm on the MAN engines.