Users' Opinions On Various Makes of Engines Needed

[Baker]

Interesting premise there Baker; the way you stated it anyway. "A truck gets up to speed and then the load decreases significantly." By "load"... You do mean the load of hp. required for accelerating the inertia of a truck's dead weight... correct? Once up to speed the truck engine has to overcome other uniquely variable loads [such as tread designs, tire pressures, winds, bearing designs] than before due to natural airflow blockage or assistance and faster tire rotations and more bearing/grease rotations/frictions.

Therefore, although considerably different in many respects/aspects of friction and natural property blockage/assistance during acceleration and after attaining cruise speed, the overcoming inertia "load" during acceleration for a boat engine also decreases significantly once hitting cruising speed... correct? That is of course depending on speed reached, how quickly speed is reached and what design hull is riding in what manner either in or over the water.

Of course each "load" factor for land or water craft, of accelerating weight and then maintaining speed, has included in its formula just how fast to accelerate to reach and maintain a desired speed.

https://www.google.com/imgres?imgur...ved=0ahUKEwiC0KWwpL7XAhUr6YMKHeNWBn0Q9QEIKjAA

In my example, I was assuming the engine is properly sized for the mission. Look at my engines. That is a planing boat. I run it on plane. I am running it at about 75% power at normal cruise. That 75% power is constant at cruise. Many people on here run at displacement speeds with larger engines. Then yes, there may be some "coast" after reaching cruise speed. But then again, it is only because an excess of power. Take Eric's little boat with his 50hp engine. He is likely running close to 60-70% power at 6 knots. And that power is constant at that speed. TO put it very simply, water is 10 times more dense than air. And if your boat engine is properly sized for the mission, it will likely be doing a constant 60-70% power at cruise.

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.

 

[smitty477]

The BMW and Hino and many uncommon marine engines almost always have good solid base engines, otherwise they would have never made it in the other applications (ag, industrial, road) that usually precede marine packaging.

The problem is in the marine specific parts. I know the Hino and BMW used a lot of aluminum parts in contact with coolant with the expected corrosion issues. Trying to find replacement parts is difficult and expensive. Many of these engines have been pulled running fine, but with corrosion issues, and new power installed.

So if looking at an engine that is no longer in production or supported, make sure you can get parts. Look up things like exhaust manifolds, heat exchangers, etc.

If you can't find replacement parts, that does not mean that it is a bad engine. Many orphans are out there running fine. But owning one means a risk of a forced repower just due to parts. Any purchase price should be adjusted due to that very real liability.

Cats- generally can still get almost anything.
Cummins- can get most anything, but the old V-block 504, 555, 903, etc are a challenge.
Volvo- some older models now in orphan status, what you can get is $$$
Deere- Not much experience, but seems ok
Detroit- Long out of production, but still can get most anything
Yanmar- Seems like you can get anything, but $$$
Lehman- Can get most anything, but from limited vendors
Perkings- Can get most anything for the base engine, but some marine specific parts are NLA and hard to source.

I found that sourcing Hino parts to be about the same or a bit less in $$ than the Cummins 6b equivalents with things like manifolds, risers, etc mentioned above. The frequency of required replacement for these parts were much less in either time or hours of use based upon many owners responses over the years.

 

[smitty477]

In my example, I was assuming the engine is properly sized for the mission. Look at my engines. That is a planing boat. I run it on plane. I am running it at about 75% power at normal cruise. That 75% power is constant at cruise. Many people on here run at displacement speeds with larger engines. Then yes, there may be some "coast" after reaching cruise speed. But then again, it is only because an excess of power. Take Eric's little boat with his 50hp engine. He is likely running close to 60-70% power at 6 knots. And that power is constant at that speed. TO put it very simply, water is 10 times more dense than air. And if your boat engine is properly sized for the mission, it will likely be doing a constant 60-70% power at cruise.

Yes - of course you are correct. That is why the 'mileage' of any marine craft is always much less than a similarly powered road vehicle. Does not matter if you compare them at 2 , 10 , or 50 mph the lower loads always favor the road application. Same with the acceleration curves.

 

[Baker]

I found that sourcing Hino parts to be about the same or a bit less in $$ than the Cummins 6b equivalents with things like manifolds, risers, etc mentioned above. The frequency of required replacement for these parts were much less in either time or hours of use based upon many owners responses over the years.

Which brings up another point. Cummins are so prolific that there is an aftermarket for them. Take the coolant heat exchanger for example. THe Cummins sourced part is $1900. But you can find an aftermarket supplier(Mr. Cool) and get the HE for $860...not bad.

 

[smitty477]

Which brings up another point. Cummins are so prolific that there is an aftermarket for them. Take the coolant heat exchanger for example. THe Cummins sourced part is $1900. But you can find an aftermarket supplier(Mr. Cool) and get the HE for $860...not bad.

Yes - aftermarkets available for trans coolers , oil coolers , fuel coolers, risers, etc.
Same with Hino's as well - Lenco, Sendure, Mr Cool, national exhaust, Greenwater etc.
Many sources for many of the parts if/when you consider good aftermarket suppliers.

 

[Art]

In my example, I was assuming the engine is properly sized for the mission. Look at my engines. That is a planing boat. I run it on plane. I am running it at about 75% power at normal cruise. That 75% power is constant at cruise. Many people on here run at displacement speeds with larger engines. Then yes, there may be some "coast" after reaching cruise speed. But then again, it is only because an excess of power. Take Eric's little boat with his 50hp engine. He is likely running close to 60-70% power at 6 knots. And that power is constant at that speed. TO put it very simply, water is 10 times more dense than air. And if your boat engine is properly sized for the mission, it will likely be doing a constant 60-70% power at cruise.

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.

"TO put it very simply, water is 10 times more dense than air."

Also TO put it very simply... my brain is 100 times more dense than either!

Happy Thinken Daze! - Art

 

[Nomad Willy]

Baker wrote;
“Take Eric's little boat with his 50hp engine. He is likely running close to 60-70% power at 6 knots”

Close;
6.15 knots
37hp
50% load (2300rpm)

A bit more efficient that you thought.
But thanks for think’in of me.

 

[Nomad Willy]

“Originally Posted by Baker View Post
Assuming 50mph average....that is 600,000 miles in 3 years. I am having a hard time believing that. And they are not at higher RPMs. A truck gets up to speed and then the load decreases significantly.”

And unless they are in Kansas they go up and down hills all day long, frequently at WOT and overloaded and not at the best rpm for that.

 

[Seevee]

We can't compare truck diesels to boat diesels because there aren't any boat diesels any more.

There have been a few small purpose built marine diesels in the past such as the the Volvo MD series up until 1984. (It was one of their good engines) Almost all new "marine" diesels are truck, bus, or tractor engines that have been marinized.

Yanmar tries to market their marine engines as "purpose built" and give them a different model number from the tractor engines, but they are still basically the same with a marinizing kit.

I agree that Yanmar have great parts service. That has been Volvo's downfall.

AusCan,

Well we aren't comparing truck to boat diesels. I don't anyone said that. We are comparing different boat diesels with each other. And while most engines aren't "boat" specific when they are made, there sure are after they are "marinized". The parts put on the motors can make a HUGE difference. Most are made for cars, trucks or heavy equipment and converted to marine use.

The manufacturer and whom ever modified it and who ends up servicing it can make a HUGE difference.

 

[Benthic2]

Does anyone think it makes a difference when an engine was made in an engines production run ? What I mean is if "Engine X" was produced for 20 years...does it get refined over time so that one produced in year 20 is much better than one produced in year 1 because the manufacturer addressed the known failures that developed ?

 

[BandB]

Does anyone think it makes a difference when an engine was made in an engines production run ? What I mean is if "Engine X" was produced for 20 years...does it get refined over time so that one produced in year 20 is much better than one produced in year 1 because the manufacturer addressed the known failures that developed ?

Absolutely. How much difference depends on the engine, but some have a rough initial run. I personally would prefer not having the first of anything.

 

[tiltrider1]

The true measurement of an engines life is neither miles nor hours but fuel consumed. The harder you work the engine the more fuel it consumes. With the Isuzu diesel I referenced earlier it ran for 30,000hrs but used only 15,000 gallons of fuel in that time. That’s 1/2 gallon per hour. At 2000 rpms under 35% load it would burn 5 gallons an hour. So is it a 30,000 hr engine or a 3,000 hr engine?

 

[Airstream345]

Wow, quite the debate here.

To the PO: I think you should buy a boat with an engine in it, maybe two. Make sure they are what you want and have been well maintained. Get a survey. Be prepared to maintain the engine(s) just as well if not better under your stewardship. Enjoy the sound of diesel motor(s) at cruising speed.

 

[knotheadcharters]

Opinions are like .... well you know. Facts are facts. A lot of high hour engines, different brands all running well and then there are a lot of low hour engines all brands that have been grenades and have had issues.


A few things I do know. I am a professional mariner and have come to love and rely on DD 6-71's in any configuration. The last tug I ran we had two as generators constant 1800rpm Naturals. We ran them for months on end and changed the oil every 500 hours. Never a problem.


A friend of mine is also a Tug Captain and has over 200K, yes 200,000 thousand hours on his Detroit's. The heads have never been off! Everything else has been changed of course and regular maintenance was done,


My personal boat, 6-71 Tib's, 1200 hours, 28 years old and run like a top. No smoke at start up at all.


Only used a few months of year( I'm always working)
When I'm gone they stay cold, no regular start ups or ran at the dock.


As far as economy, I mostly run at 8-9 kts, 1100rpms and burn 6.13 gallons an hour total and that includes running a 15Kw generator. At 15 kts, 1800 rpms, I am burning 18 gallons an hour total. Now I know to a lot of you, that's a lot but my boat is not a "Trawler".

 

[FF]

"Detroit- Long out of production, but still can get most anything"

This is true fior the 2 stroke DD , but new excellent DD engines are being sold daily.

The hassle is they are about 400HP in the tamer versions which is way out of white boat trawler needs.

Sadly to meet the air police they are all electronic injection which causes higher repair prices and can be dangerous to forward motion in thunderstorms.

 

[Art]

Opinions are like .... well you know. Facts are facts. A lot of high hour engines, different brands all running well and then there are a lot of low hour engines all brands that have been grenades and have had issues.


A few things I do know. I am a professional mariner and have come to love and rely on DD 6-71's in any configuration. The last tug I ran we had two as generators constant 1800rpm Naturals. We ran them for months on end and changed the oil every 500 hours. Never a problem.


A friend of mine is also a Tug Captain and has over 200K, yes 200,000 thousand hours on his Detroit's. The heads have never been off! Everything else has been changed of course and regular maintenance was done,


My personal boat, 6-71 Tib's, 1200 hours, 28 years old and run like a top. No smoke at start up at all.


Only used a few months of year( I'm always working)
When I'm gone they stay cold, no regular start ups or ran at the dock.


As far as economy, I mostly run at 8-9 kts, 1100rpms and burn 6.13 gallons an hour total and that includes running a 15Kw generator. At 15 kts, 1800 rpms, I am burning 18 gallons an hour total. Now I know to a lot of you, that's a lot but my boat is not a "Trawler".

Now - there's a statement posted on a specific type of diesel engine! 200K hrs. = OMG! And, I believe you... sort of. 200K hrs. means that engine was run 24/7 absolutely non stop for every hour of 22.9 yrs. So... let's say it ran average of 2/3 of every hour of the year. That = 34 yrs. Yup... I can visualize that happening on a tug! But, WOW... 200,000 hours without even having the heads off. Those exact design engines should be built again!

For your boat: 1,200 hrs. in 28 yrs... = 43 hrs. per. yr. ... which = 4651 yrs. if 200K hrs. were to be reached at your per yr. hr. count. That's over twice as long as since Jesus walked the Earth!! LOL

Imagine if JC had a DD 6-71 to work miracles with. This would be a different world today!!

Happy Engine Chat Daze! - Art

 

[Fletcher500]

A friend of mine is also a Tug Captain and has over 200K, yes 200,000 thousand hours on his Detroit's. The heads have never been off! Everything else has been changed of course and regular maintenance was done,/QUOTE]

That is amazing. I grew up working on fishing boats and many had the Detroits. I don't recall every having a major mechanical causing us not to make it back to the dock.

Good discussion. Its always interesting to read about others peoples experiences.

 

[bayview]

Dont know where you got your cummind ideas but aftermarket parts are readily available for the inline sixes. Anyone can fix them.

Perhaps you are painting with too broad a brush. The makers have had many models over the decades and the results vary widely.

 

[Nomad Willy]

Tiltrider1 wrote;
“Just to drive some of you nuts. I just sold a 2001 Isuzu nqr with 30,000 hrs on the engine. At 28,000 hrs I had the head rebuilt to stop the smoking. That engine still has plenty of life left in it.

What’s an nqr ?

Then he wrote;
“The true measurement of an engines life is neither miles nor hours but fuel consumed. The harder you work the engine the more fuel it consumes. With the Isuzu diesel I referenced earlier it ran for 30,000hrs but used only 15,000 gallons of fuel in that time. That’s 1/2 gallon per hour. At 2000 rpms under 35% load it would burn 5 gallons an hour. So is it a 30,000 hr engine or a 3,000 hr engine?”

I like the idea of fuel burned re engine life but it gives no room for anything but ideal history. And there probably isn’t an engine out there that hasn’t experienced bad moments like shutting down when hot or running up to speed while stone cold. Starting the engine for a few moments before oil went back in during an oil change. Most have probably experienced some kind of overheat. My engine probably would have if I didn’t have a Murphy switch protector. **** happens they say ... and it does. Small things like fly stuff and then there’s death. An engine being in a boat for 15-30 yrs almost guarantees that non-ideal things have happened.

Then there’s how ther’e run. Maintanance. So many operators.
I think Marin Fare had a total strokes notion of engine wear. I know at one time he thought it was a matter of how many times a piston went up and down. But there’s the very meaningful variables. One piston experiences high side loads against the cylinder wall under heavy load. Another never gets it’s oil warm/hot enough to burn off the undesirables residual in the oil. The oil for a trawler engine is frequently chosen by the boat owner that dosn’t have a manual, or dosn’t care to follow it. Too many variables.

Go talk to the guys at Lugger Engines in Ballard Seattle. They say “run’er had and don’t baby it”. One Lugger guy actually said “run it like you hate it”. That was in a PMM article.

Lots of variables in history from general maintenance to operators to weather to personal whims. Everybody’s an expert on how to run an engine and over many years there’s accidents that just happen.

So IMO total fuel burned has merit as it may be more meaningful than hours run in one respect. Load is closly related to fuel burned. But there’s all those variables. A DD at low revs burns considerably more fuel (hp per gal) than a fully modern engine at 70% load.

But total fuel burned probably has more merit than hours run in most cases. Would anyone agree w that? But I have yet to see a boat w a total fuel burned gauge.

I think the only place where it really dosn’t apply is re an engine that’s been severly underloaded or run very close to the pin but these are both extremes. Running real hard is extremely rare in trawlers but running very light is common. So this theory of engine wear should work fairly well for those that dismiss underloading as not the least bit bad.

I hope this was the thread that asked for opinions.

I do have a problem w tiltrider’s
“At 2000 rpms under 35% load it would burn 5 gallons an hour.” but it’s not important.

 

[Baker]

Does anyone think it makes a difference when an engine was made in an engines production run ? What I mean is if "Engine X" was produced for 20 years...does it get refined over time so that one produced in year 20 is much better than one produced in year 1 because the manufacturer addressed the known failures that developed ?

Yes. The Cat 3196 would be a good example. It is a great engine on land. But it had some pretty big issues with the aftercoolers in the marine versions. Class action lawsuits, the whole bit. I think they had 8 iterations of the aftercooler over the span of about 6 years. I honestly do not know if they ever figured it out. At 660hp, not a trawler engine but I was looking at boats with them.

My Cummins also have different iterations. That is why when you buy parts, the first thing they ask for is serial numbers and/or CPL. If they don't ask that question, I would not buy parts from them. The 6B series of engines were not always as highly regarded as they are today. It took Cummins awhile to get it figured out. But you have to give them credit for sticking to it and continuing to revise their designs.

 

[sunchaser]

The true measurement of an engines life is neither miles nor hours but fuel consumed.

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.

 

[caltexflanc]

But I have yet to see a boat w a total fuel burned gauge.

Floscans can track that and the gauges for some modern engines can as well. Then of course there's the good old log book.

 

[boathealer]

But you have to give them credit for sticking to it and continuing to revise their designs.

Likely just a business decision - probably tens of millions in tooling that was worth fixing up.....

 

[Baker]

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.

80% load....in theory. In actuality, it might be 100% load or even worse!!!

 

[Xsbank]

Wow, 5 pages. Do you think the OP can make a decision with all this? The engine is just one consideration, pick a boat you like, get it surveyed and live happily ever after.

 

[AusCan]

Does anyone think it makes a difference when an engine was made in an engines production run ? What I mean is if "Engine X" was produced for 20 years...does it get refined over time so that one produced in year 20 is much better than one produced in year 1 because the manufacturer addressed the known failures that developed ?

The issues usually get refined as time goes on, but there are exceptions. It is not always a constant improvement.

The Caterpillar 3516's originally were built with wet exhaust manifolds. The wet manifolds were failing after about 5 - 10,000 hours so Caterpillar changed to a dry manifold. The first dry manifolds were a disaster, failing within the first 1000 hours. Eventually these problems were addressed but it took several more years.

 

[BandB]

Yes. The Cat 3196 would be a good example. It is a great engine on land. But it had some pretty big issues with the aftercoolers in the marine versions. Class action lawsuits, the whole bit. I think they had 8 iterations of the aftercooler over the span of about 6 years. I honestly do not know if they ever figured it out. At 660hp, not a trawler engine but I was looking at boats with them.

My Cummins also have different iterations. That is why when you buy parts, the first thing they ask for is serial numbers and/or CPL. If they don't ask that question, I would not buy parts from them. The 6B series of engines were not always as highly regarded as they are today. It took Cummins awhile to get it figured out. But you have to give them credit for sticking to it and continuing to revise their designs.

Very good examples. Odd how CAT is the favorite of so many owners and captains, but they've had issues like that a couple of times on new engines. Now, I don't know if they've had more than others or their's just more widely known, largely due to them addressing the issues.

Most new engines today are very mature even with the requirements for new anti-pollution levels. Not many "new" engines, perhaps because the companies have been so involved meeting standards, so I've heard of very few problems. Common rail and turbochargers are now just common, every day characteristics. Now the exceptions have been VW and Mercedes with their recalls and Cummins 6.7 liter in Dodge Rams with water pump bearings that can overheat and lead to fire.

 

[Jbear]

Well, thanks for the question! Ford Lehman's are the best. Duh.... [emoji23]

 

[Nomad Willy]

Jbear,

Perkins is better than FL and I replaced my Perkins cause it was old and had a flame thrower type starting heater. Perkins was OK though.

 

[BruceK]

It`s quite likely some owners keep their old boats because they like their FLs and know they won`t get them or an equivalent(with some exceptions) on newer boats.