Question on MAN's

[Genesis]

The reason the MANs are so smokey at idle is that they use sequential turbocharging and INSANE boost pressures.

This in turn requires lower than usual base compression numbers so that the cylinder heads don't come up through the salon floor at full power...... result: low power smoke.

 

[Capt K]

Thanks, Scrod, and everyone else! If the MAN tech has any further info, let me know. Surveys are set for the 27th. I guess I'll be onboard running north in a month or so.

Thanks, again everyone, as always!!!

K

 

[captddis]

They also idle on half the cylinders.

 

[Avenger]

Okay, spoke to the M-A-N guy today and he said he knows of no specific pattern failures on the 2866LE401. He did say that most of the problems he sees are usually minor, and of a random nature. Although he also admits that he doesn't see a lot of the six cyl. engines. I don't know what the local population is, but if the mechanics don't see a lot of them it's usually a good sign. I hope your friend has good luck with his new toy.

 

[jim rosenthal]

Who really love MAN diesels are the Volvo guys....because it keeps Volvo from having the worst rep in the business. But not by much. Yes, Captain, I know your Volvo ran well but you only did 16kts and you're the only one I know who likes them. Now, CATs, THERE'S a reliable diesel.

 

[SKYCHENEY]

We've owned alot of Cats in trucks and construction equipment and most of them have been good, but our Volvo's in the construction equipment are quieter and smoother and more fuel efficient. So far, they have been alright too. I have one Volvo with over 10,000hrs on it now, so we'll see. They tell me I should get about 14,000hrs before overhaul.

I realize that we are not really talking about the same thing here due to the high hp/displacement ratio of most modern marine engines, but at least you can see how these companies seem to stay in business. If all of their engines lasted only 2-5000hrs, they probably wouldn't be around long.

Now Cummins---there is a real diesel, in my experience anyway.

 

[Genesis]

The problem with marine engines is that the market is too small for them to REALLY care.

Here's an interesting statistic for you..... out of all the oil we burn, twice what goes up in smoke as distillate (diesel) goes up as gasoline.

That puts into perspective just how much of a baztard stepchild marine engines really are, especially in the larger pleasure boats like ours.

It makes one wonder - would you be better off marinizing your own motor? Certainly it can be done. Certainly truck engines don't price out like boat engines......

Things that make you go "hmmmmmm...."

 

[MarioG]

Hey at least MAN gives you those pretty chrome valve covers.

 

[34Hatt]

It makes one wonder - would you be better off marinizing your own motor? Certainly it can be done. Certainly truck engines don't price out like boat engines......

I read something about this cause there are company doing this with the Cummins 5.9 out of trucks, the cam is different which also means different fuel pumps and injectors and so on. Then you get to resale it was not the same so after the Investigation I decide to stick with the full marine version and pay more after all, you all can't be the only ones paying a arm and leg for marine stuff

 

[REBrueckner]

One would HOPE that experienced engineers and designers would do a better job than amateurs at developing and manufacturing marine engines. But if there really is much custom design involved, and uniques parts, the small volume likely means higher prices.
On the other hand, if you convert a truck diesel to marine and choose a reduction drive and prop to get the rated RPM from the engine, you'd think it would give reasonably good service. A recent thread discussed how a Detroit Diesel truck engine differed from marine. Were there internal differences, like cams, valves or cylinder, or rings?? I don't remember any. But just having to buy all the external accessories (exhaust manifolds, heat exchangers, oil coolers, etc, etc, transmissions at retail might negate much of the anticipated cost saving.

Many,many years ago my Dad converted a 327 cu in chevy gas engine for our 38 ft Matthews. It had about 11,000 miles from a wrecked station wagon. He bought a reduction drive and Barr exhaust manifolds. I think he sized the prop for about 3,000 RPM max..but where he got that figure I have no idea...likely it just sounded right...
I still remember rounding a doorway in a barge (as a kid) when my Dad and some friends test started it on an engine bed...damn thing spewed flames out the exhaust just as I arrived....It scared me so much I fell down...But it lasted the eight or ten years we had the boat...

 

[captddis]

Automotive / industrial engines can certainly be converted with good results. The trick is to use the correct internal parts. I bought a high output brand new 8v92TA industrial engine and converted it to marine and boosted it to 650 HP from 585 Hp. I went item by item and compared the parts from the old engine to the new. The new engine had the brushed liners and correct heads, oil cooler , harmonic balancer etc. I had to change the cams, blower drive gear, flywheel and flywheel housing and remove the aftercooler. Also had to use the 130 injectors. Remember until 87-88, almost all of the marine engines were modified by the marinizer. In most cases on a Hatt it was done by Covington.