Users' Opinions On Various Makes of Engines Needed

[Nomad Willy]

Bruce indeed,
But the cost of replacement is great.
If I had one in a boat and it ran fine, didn’t overheat or smoke too much I’d keep it. No doubt. And if I was looking at old boats editing out the FL’s would severly limit my choices.
I even had one once marinized by Sabre

 

[Jbear]

My reply was kinda a joke. Most folks are going to like the brand of motors they have or have used...

 

[BandB]

My reply was kinda a joke. Most folks are going to like the brand of motors they have or have used...

And one of the reasons is that most are good. Just like most boats are. There are not many bad boat builders and not many bad engine builders.

 

[BruceK]

My reply was kinda a joke. Most folks are going to like the brand of motors they have or have used...

I know, and of course I have "owner bias". But they and Perkins NAs are great old simple robust engines,long lived, parts available,well suited to displacement speed trawlers, anyone can work on them. Old fashioned, sure, but plenty of positives. Give me 2 identical older boats, one with FLs, one with Volvo 165s, I`ll take the FL version every time.

 

[BandB]

I know, and of course I have "owner bias". But they and Perkins NAs are great old simple robust engines,long lived, parts available,well suited to displacement speed trawlers, anyone can work on them. Old fashioned, sure, but plenty of positives. Give me 2 identical older boats, one with FLs, one with Volvo 165s, I`ll take the FL version every time.

I'd take the one that had been maintained best and surveyed best.

 

[BruceK]

In my proposition, they are "2 identical older boats", save for brand of engine. That includes engine condition/maintenance.It`s theoretical, intentionally so. Come on, deal with it. Do you prefer the Volvos?

 

[ghost]

Engine reliability cant be measured by brand name, hours or even oil change history. Opinions are fun, and so is this thread, but that's as far as it goes.

 

[ghost]

Except for Volvos. I hate Volvos, because they cost me a lot of money. Those damn dirty Volvos.

 

[BandB]

In my proposition, they are "2 identical older boats", save for brand of engine. That includes engine condition/maintenance.It`s theoretical, intentionally so. Come on, deal with it. Do you prefer the Volvos?

No....you find two absolutely identical and then your choice is fine. Just I can't imagine two so identical. Where I am, I wouldn't prefer the Volvo's. Now, if I was in certain parts of Europe, I might.

 

[tiltrider1]

Not in the real recreational marine world. As oft mentioned in this thread (thanks Eric), adherence to proper maintenance trumps all and puzzles most. Throw in wrong prop and running at 80% + load and problems arise in short order.

You can tell all this the from an hour meter?

 

[ranger58sb]

I do have a friend that just bought a Selene 53(lucky bastard) with a Cummins 6CTA at 450hp. That boat is overpowered IMO. But it already has 6000 hours on it and a very complete log/history that shows it will likely go at least another 6000 and probably more. And the reason is that it is barely working. Just a WAG but I would say it is probably around 30% at 8 knots. That engine in a boat like Ski's(which he does have that same engine) that is run up on plane all the time is about a 5000 hour engine assuming all the other failure prone stuff doesn't kill it.

I dunno... we usually make between 7.5-8.5 kts our twin 450s at 1200 RPMs, depending on sea states, wind, etc. 35 ton boat, planing hull, engine temps high enough at those RPMs.

I'd imagine that Selene is at least 2x our displacement, so maybe a single 450 isn't that out of line, if at all. Could also depend on reduction gearing, etc.

Ski would likely know...

-Chris

 

[Ski in NC]

The 450 Cummins seems to do fine in trawler service. The Selene is a case in point, although we don't know how hard he actually runs it. I know of other trawlers with this engine (or the 480CE) that seem to do fine running at 1000-1200rpm and 2-3gph.

On mine, I have made two trips from NC to the Keys/Bahamas running almost exclusively at 950-1050rpm, about 2gph. Engine did fine. Last trip I was short on time and fuel was cheap, so I ran 1800-2100, about 18-21kts and 8-12gph. Again, the engine did fine. Burns clean at either speed, blowby is minimal, runs smooth, clean oil samples. Now at 2400hrs by me, 1200 when I bought it used so about 3600hrs.

At this rate I do not fear that it will be needing work by 5000hrs as posted above!! That's only 1400 more hours.

While it is a high output turbo diesel, it is only a couple liters more displacement than a Lehman 120. Running light load on the Cummins means the turbo is doing nothing and the engine is in an operating mode almost identical to the Lehman as far as loading goes.

Since it is propped for planing speed, while 950-1050 sounds like a real low rpm, it actually has a good bit of load on it. It is not idling, actually has some hearty fuel clatter.

If the loading ends up glazing the liners, in a weekend I could pull it down and put new cylinder kits in. Nice to have replaceable wet liners.

I think the 450C is a good match for the Selene.

Even in the sportfish fleet, where they are run hard and put up wet, the 450C's take the abuse better than others in that class. That's why I bought mine.

How's that for some "owner's bias"?? (which is real, by the way, see it all the time)

 

[Nomad Willy]

You can tell all this the from an hour meter?

I don’t see the connection to an hour meter or implications that hours run represents all re engine wear/condition.

IMO the hours meter isn’t meaningless but is information that can be applied to other observations. Everything one can take in may count a little bit ... or a-lot.

Here is the only post by Sunchaser that could possibly connect hours to engine life.
“Just traded in my 12 year old Suburban. It had about 1700 hours. I'm impressed with 12K hours on a boat with a Cummins. Much tougher operating parameters than a light duty truck with same engine.

But how do you put 12K in 17 years on a small boat unless commercial?”

But I just don’t see it.

I think there’s something to take away from your post #72 but I don’t think I understand it.

 

[Baker]

The 450 Cummins seems to do fine in trawler service. The Selene is a case in point, although we don't know how hard he actually runs it. I know of other trawlers with this engine (or the 480CE) that seem to do fine running at 1000-1200rpm and 2-3gph.

On mine, I have made two trips from NC to the Keys/Bahamas running almost exclusively at 950-1050rpm, about 2gph. Engine did fine. Last trip I was short on time and fuel was cheap, so I ran 1800-2100, about 18-21kts and 8-12gph. Again, the engine did fine. Burns clean at either speed, blowby is minimal, runs smooth, clean oil samples. Now at 2400hrs by me, 1200 when I bought it used so about 3600hrs.

At this rate I do not fear that it will be needing work by 5000hrs as posted above!! That's only 1400 more hours.

While it is a high output turbo diesel, it is only a couple liters more displacement than a Lehman 120. Running light load on the Cummins means the turbo is doing nothing and the engine is in an operating mode almost identical to the Lehman as far as loading goes.

Since it is propped for planing speed, while 950-1050 sounds like a real low rpm, it actually has a good bit of load on it. It is not idling, actually has some hearty fuel clatter.

If the loading ends up glazing the liners, in a weekend I could pull it down and put new cylinder kits in. Nice to have replaceable wet liners.

I think the 450C is a good match for the Selene.

Even in the sportfish fleet, where they are run hard and put up wet, the 450C's take the abuse better than others in that class. That's why I bought mine.

How's that for some "owner's bias"?? (which is real, by the way, see it all the time)

I guess I said it was overpowered "IMO" but what I was really trying to say is that a trawler purist would call it overpowered. I do believe it will do perfectly fine in that application(the Selen 53).

Ski, I wouldn't imagine your engine to suddenly crater at 5000 hours. I guess all I was saying is that people that run them fairly hard would expect about 5000 hours. You generally do not run yours hard. I do. I'll be perfectly happy to get "only" 5000 hours out of mine.

Coincidently, you mention the Lehmans ref displacement. Check out the 6Bs displacement versus the Lehman....almost exactly the same.

Ranger, your Ranger 42 is 70,000 pounds??? I find that hard to believe.

 

[ranger58sb]

Ranger, your Ranger 42 is 70,000 pounds??? I find that hard to believe.

Ummm... no... it's actually about 28K dry, but earlier I just used the "official" gross displacement (35K).

-Chris

 

[Baker]

Ummm... no... it's actually about 28K dry, but earlier I just used the "official" gross displacement (35K).

-Chris

OK....you said 35 tons...just a typo I reckon...as you were...

 

[ScottH]

Many, many thanks!

I want to thank all of you for taking the time to give me your opinions on various makes of diesel engines. I don't have to tell anyone that buying a trawler is a major purchase, and the engines are a critical part. It would be too nice to have pockets deep enough to be able to just throw a couple of new engines in the boat if the existing ones turned out to be junk. We don't. Your comments have been a huge help for us to make a good decision. Thank you, thank you, thank you!

 

[Nomad Willy]

ScottH,
There were only a few engines mentioned on this thread. There are many more that are not mainstream. Like my own Mitsubishi marineized by Yukon Emgines. They produce a very fine product and have been doing so since the 60’s. Yukon (formerly Klassen) has been supplying the fishing industry w propulsion engines as well as generators and are highly reputable. Some small companies are not top knotch. Some are not of course but one needs to do the research anyway.

Many of these engines can be had for far less than the name brands. The S4L2 Mitsubishi that my engine is based on is probably as good as the name brand engines. Lugger had an engine that I could have used but actually cost more than double what I paid. The Mitsu S4L2 is available from Holland as a Vetus or from Westerbeke here in the US. Same engine. And the Lugger engine was based on a common Japanese industrial engine.

So Scott you’ve probably just touched the surface. And diesel mechanics are everywhere. One almost always dosn’t need a brand name mechanic any more than one needs a brand name surveyor. It may help but most all the time probably not. A good mechanic and a good surveyor are just that. Unless of course you’ve got something like a Detroit diesel or a wood boat.

 

[T4Liberty]

ScottH,

Here is my $.02.

If we assume that the boat you choose:

1. has an engine(s) that have been maintained and operated properly and you will continue same
2. is a full displacement boat or will be operating at FD speeds
3. that the engine has an appropriate hp rating for the application (most often boats have far more hp than is required)

Then...

A. I wouldn't worry too terribly much about fuel efficiency. How you operate the boat will be a much bigger factor than the make of the engine.

B. I believe the best determinant of the life cycle of an engine (with the assumptions above) is horsepower rating to cubic inch ratio. I think it best to look for engines that have a hp rating that is 60% or less of the cubic inch capacity. The lower the better.

 

[Art]

ScottH,

Here is my $.02.

If we assume that the boat you choose:

1. has an engine(s) that have been maintained and operated properly and you will continue same
2. is a full displacement boat or will be operating at FD speeds
3. that the engine has an appropriate hp rating for the application (most often boats have far more hp than is required)

Then...

A. I wouldn't worry too terribly much about fuel efficiency. How you operate the boat will be a much bigger factor than the make of the engine.

B. I believe the best determinant of the life cycle of an engine (with the assumptions above) is horsepower rating to cubic inch ratio. I think it best to look for engines that have a hp rating that is 60% or less of the cubic inch capacity. The lower the better.

Exactly! Couldn't be said much better.

 

[DavidM]

Your advice would preclude the use of a 370 hp Cummins 6BTA or a 450 hp 6CTA and other high output engines. As Ski and I have said on the other thread, there is nothing wrong with running a 60 hp per liter engine at 10 hp per liter. Ski, I and others on this and the right engine for me thread do it all of the time.

They will last just as long running one of the above engines at that low power setting as an engine that only makes 25-35 hp per liter like a Cummins 6BT which is turbocharged but not after cooled or a Lehman/Perkins that is non turbocharged.

So if you find just the right semi displacement hull boat and it has one of the above engines or another high output engine like the Yanmar 6LP or 6LY, don't stick your tongue out at it. It will work fine for you and who knows you may like running it at high power once in a while.

David

 

[caltexflanc]

I want to thank all of you for taking the time to give me your opinions on various makes of diesel engines. I don't have to tell anyone that buying a trawler is a major purchase, and the engines are a critical part. It would be too nice to have pockets deep enough to be able to just throw a couple of new engines in the boat if the existing ones turned out to be junk. We don't. Your comments have been a huge help for us to make a good decision. Thank you, thank you, thank you!

The key is to get an independent mechanic who works on that type of engine frequently AND does engine surveys as part of their practice to do a thorough engine survey as part of your buying process. It will be some of the best money you ever spend on a boat if you get the right guy.

I have to add though it sounds like you are very tightly budgeted and that's dangerous.

 

[FF]

The problem is a really good engine inspection can run at least a grand.

Thats a lot to invest , especially if you have 2 or 3 boats that are of real interest.

The simplest system for avoiding a worn out engine , which could be very low time , due to abuse is easy.

Tell the broker or owner you will visit and want the engine to be DEAD COLD, not run for a day or so.

Check by feeling it , if its warm , walk away.

On cold start you should see a bit of white smoke , but not a lot unless its near freezing .

The coolant temperature at which the white smoke clears is a cheap indication of compression.

 

[sunchaser]

The coolant temperature at which the white smoke clears is a cheap indication of compression.

Few boats adequately warm up at the dock. This is why a good seat trial is needed.

 

[FF]

Few boats adequately warm up at the dock. This is why a good seat trial is needed.

True enough , but if the engine runs clean a min or two after start up you may have a winner.

When it takes 10 min at heavy throttle and a circ water temp of 140-160 to see the smoke depart , you might have a low compression and oil consumption problem.

For many folks this does NOT have to be fixed. Most hi time engines will still crank out another thousand hours or two, and at 200 hours a year 10-20 more years will only amount to 3 or 4 cases of extra lube oil.

 

[caltexflanc]

Every good engine survey or annual check I've ever seen by top notch mechanics, began with the cold start, exhaust observation test.

Something like this (which is aimed at old Detroits but also more applicable to others than the opening sentence states)

30" Compression Check on DD, by Genesis

 

[DavidM]

That little article is excellent and as you note is mostly applicable to other 4 cycle diesels as well.

A quick, clean cold start is a pretty good indicator of a healthy engine.

David

 

[Ski in NC]

Detroit two strokes definitely show good compression with a clean cold start. Over half the engine survey is completed by a good cold start on those.

Four strokes are a little different. I have had many with a clean cold start that then flunked the blowby test. Then to troubleshoot a compression test showed one or more weak holes. Yet it still got a clean (or reasonably clean) cold start.

 

[DavidM]

Ski:

Interesting observation. Have you ever seen the opposite: an engine that was hard to start (and started with a big cloud of smoke which seems to rule out fuel supply problems) but had no noticable blowby with the redneck test even under load?

If so, it was probably poor injection spray pattern, right?

David

 

[Ski in NC]

Dave, yep, seen the opposite. Hard starting smoky as heck engine that otherwise passed the other tests. A few examples that come to mind: Some Cummins 6B, 6C, Yanmar 6LY, MAN 284X mechanicals, Volvo 41/42. Mostly when ambient temp is low.

Many high output diesels lower the compression ratio to minimize temps and thermal stress on pistons and heads. Downside is nasty cold starts. But engines are otherwise fine and clean up under some load.

My 6C is pretty stinky anything below about 50F block temp.

In my experience, very rare to have injector problems that cause cold smoke but clean up under load. Many many injectors replaced for cold smoke with improvements rare.

High output engines tend to have CR about 14.5-15.5, but varies. Same block in continuous rating will have CR around 16-18. Thermal stresses not such an issue with lower specific rating, so they shrink the piston bowl to get higher CR. Nice clean cold starts then.