Volvo vs. Cummins

bligh said:

From what I understand, Nordic Tugs went with the Volvo engine in their 32's and 26's since the larger Cummins engine would not fit in the engine room. I am not sure if there was some redesign of the engine compartment or main salon cabin sole of the 32 at the time, but that is what they told me. Cummins engines are still being installed in many other NT's.

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I thought it also had to do with Cummins not having engines in the sizes they needed that meet the new emissions standards.

The only thing I have heard regarding the 6LP was a class action settlement that involved the the valves on 1997 - 2002 6LP models.

Carolena said:

I thought it also had to do with Cummins not having engines in the sizes they needed that meet the new emissions standards.

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Yes the smaller engines, I presume.

My research says both Volvo and Cummins make exceptional marine diesel engines, probably the best two out there in the sizes most of us would consider. Chessie Cummins built his first diesel around 1920 and early ones were for marine (he was a boating fanatic). I am not sure Volvo had made a diesel that long ago but that really means nothing. Cummins has now replaced the 5.9 with the new 6.7, same horsepowers, but gobs more torque, yields notably greater acceleration and just a touch more top speed. But the 6.7 is extremely quiet and has very low emissions, compared to its very popular predecessor. I don't know what Volvo has done lately but I doubt they have been sitting on their thumbs. Their engines are in very upscale boats and that tells me they are also outstanding motors. My two cents worth. My new boat will have the Cummins 6.7 made in Indiana and shipped to France to install in my boat. I would say I am prejudiced, as I am a Hoosier. But I have fond memories of a Volvo 240D station wagon I once had, nuff said!!

"One thing is crucial with a Volvo is to keep correct coolant mixture in all the time, failure will lead to a perforated cylinder liner on No 1 piston where the flow of water from the water pump hits the cylinder liner."

This is critical on any new engine where the cylinders sit in coolant .

SCA is required , esp in a high powered unit that rings the cylinders like a bell on every power strike.

Std green antifreez is fine , but it MUST have the SCA added .

Volvo is cheaper for the boat assembler , and the "dont pay till its sold" also helps initial sale.

Cummins parts everywhere. Many independent mechanics very familiar with Cummins.

Brooksie said:

Cummins powered trucks outnumber Volvo powered trucks by maybe 100:1 or more in the US, this speaks volumes in itself and insures parts availability both OEM and aftermarket way into the future.

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+1

Sailor of Fortune said:

I beg to differ. The cost of parts is expensive when you can't get them. Volvo has shut the door on many of the older common series engines. No replacement parts being manufactured in many instances. Volvo engines enjoy a good reputation in everything other than support.
By comparison the Ford Lehman is much easier to source parts for.

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I saw this thread; did not realize it was months old and was going to disagree wtih Marin until I read my own post.

I don't know what i was thinking. I think an Alien wrote that post and signed my name.

In any case, i totally agree with SOF and can only say

In addition, I was going to respond to Marin and say that to ASSUME an engine is better because it was designed for marine application is truly out of this world.

The better case can be made that Volvo designed an engine that 90% of it's users would die before it even had 10,000 hours on it.

In the meantime, those manufacturer who took an engine that was made to run pretty much continuously, started from a far better place.

At least if you need an engine that can go non-stop for days or weeks on end.

Wxx3 said:

:

In addition, I was going to respond to Marin and say that to ASSUME an engine is better because it was designed for marine application is truly out of this world.

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As is typical of threads on this forum, you are responding to what you think I wrote, not what I actually did write. If you go back and actually READ what I wrote you will find that I said it was my understanding that Volvo marine diesels were designed for this purpose from the outset but what advantages this might give Volvo engines is something I don't know. Or words to that effect.

I don't mind if what I write is challenged, but I don't much care for being accused of writing something that I didn't write.

Joebad said:

My research says both Volvo and Cummins make exceptional marine diesel engines, probably the best two out there in the sizes most of us would consider. Chessie Cummins built his first diesel around 1920 and early ones were for marine (he was a boating fanatic). I am not sure Volvo had made a diesel that long ago but that really means nothing. Cummins has now replaced the 5.9 with the new 6.7, same horsepowers, but gobs more torque, yields notably greater acceleration and just a touch more top speed. But the 6.7 is extremely quiet and has very low emissions, compared to its very popular predecessor. I don't know what Volvo has done lately but I doubt they have been sitting on their thumbs. Their engines are in very upscale boats and that tells me they are also outstanding motors. My two cents worth. My new boat will have the Cummins 6.7 made in Indiana and shipped to France to install in my boat. I would say I am prejudiced, as I am a Hoosier. But I have fond memories of a Volvo 240D station wagon I once had, nuff said!!

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The Cummins QSB5.9 still exists as far as I know.... You might be hung up on their road stuff. And their power outputs are close but can be different. Volvo support is a nightmare....I don't care how good their engines might be.

My Volvo TMD-100A is a Turbo-charged, Marine version of a Diesel...tractor engine.

It's still in use in many single engine commercial vessels throughout the world. Hatton Marine in Seattle has never had a problem getting parts, and they even have some used parts when appropriate (I needed a replacement cooling tank about 10 years ago - used was under a BU versus maybe 3 BU for NOS).

I'm a "one rat study", but I am a satisfied rat. ?

I have had my VOLVO TMD40's for fifteen years and can attest to their ease of maintenance as I do all my own work on them. It just galls me that VOLVO does not care that they have the worst customer service in the industry. It doesn't have to be that way.

Richard (Wxx3) wrote;
"In addition, I was going to respond to Marin and say that to ASSUME an engine is better because it was designed for marine application is truly out of this world."

There are no engines in boats our size designed as marine engines. If there were they would have their flywheels on the front of the crankshaft instead of the back. Rear mounted flywheels on small boats aren't a feature on marine engines for small boats .. only conversions.

And if you were powering a boat most likely having a flywheel on the front is an advantage or offers several advantages. The option to mount the engine as low as possible in the boat is obvious but CG, engine mounts, transmissions and other things may enter into it. So an engine designed as a marine engine may have many advantages but it probably dosn't relate to the basic quality of the engines. Alloys used, machining methods, tolerances and quality of bolt on outsourced materials and components all contribute to quality. But if the engine is destined for a boat boat stuff counts.

manyboats said:

Richard (Wxx3) wrote;
"In addition, I was going to respond to Marin and say that to ASSUME an engine is better because it was designed for marine application is truly out of this world."

There are no engines in boats our size designed as marine engines. If there were they would have their flywheels on the front of the crankshaft instead of the back. Rear mounted flywheels on small boats aren't a feature on marine engines for small boats .. only conversions.

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Eric,

Sorry, but I'm going to have to throw a flag on that statement. The Volvo MD series marine diesels were designed and built for one thing, and one thing only, boats. Granted, later small marine diesels are often based on industrial or automotive designs, but some engines are definitely marine only.

Run what you got.....Some of us, in a quest for the right boat, don't have a choice...

The electric clutch for the supercharger in later models of Vulva engines was a joke. It was just not funny. Knomes, all of those engineers were knomes.

LarryM said:

Eric,

Sorry, but I'm going to have to throw a flag on that statement. The Volvo MD series marine diesels were designed and built for one thing, and one thing only, boats. Granted, later small marine diesels are often based on industrial or automotive designs, but some engines are definitely marine only.

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That might be a purpose built marine engine, but geez it is sea water cooled. I've spent a bunch of time trying to chip out corrosion blocking coolant channels on those. Most aggravating. Direct cooling is a definite cheap-out.

It does not matter if an engine is built for marine, automotive, industrial, agriculture, whatever. An engine just converts fuel and air into spin, heat, noise and smoke. Does not matter what it started life as, they all do the same thing. We just want the "spin".

What matters is the quality of the engineering that adapts the engine to the unique marine environment.

A few rules seem to apply:

NO ALUMINUM in contact with coolant. Volvo and Yanmar fail here. Lots of aluminum here like whole exhaust manifolds. So what, save 20lbs, create maintenance nightmare. Detroit, Cat and Cummins- Zero Al in contact with coolant.

No sea water oil coolers. Volvo and Yanmar again fail. Detroit, Cat and Cummins simply do not do that. Coolant cools oil, much better temp control, no corrosion issues. Oil hot enough to keep dry.

Simple serviceable coolers. Cummins uses Serck and Sen-Dure coolers, easy to service and easy to remove from engine. Cat and Yanmar similar, easy to service. Some Volvo stuff is a real PITA and since made in house, parts availability is up to them.

I can get a 30yr old Detroit cooler direct from Sen-Dure.

There are a few valid complaints about the Cummins- Stupid leaking sherwood pumps and having to pull a mount to replace. Putting the leaky pump above the HPFP on the QSB...

But in general, Cummins does a better job than just about anyone else.

I don't have much Deere experience, just not many in my fleet. Generally very good as I hear, but I think they use aluminum in coolant path too. Someone else might confirm..

Still waiting on stupid building permits. This is killing me.

Ski,

I agree on all points. Decades ago, some of the marine diesels were made specifically for the marine market. They were produced in low numbers, raw-water cooled, and designed with heavy castings to last in the marine environment. Their heavier mass allowed for smooth running, and their relatively low rpm minimized bearing wear. Many are still going strong today. I had a Volvo MD6 that ran over 30 years in salt water with no issues at all. I changed impellers when needed and replaced one mixing elbow, but never worried about the rest of the cooling system.

Now, I have a Yanmar 4JH3E that is a great engine except I worry about the aluminum heat exchanger, which although still in great shape, is a real concern as the engine ages. I change the coolant annually and even check the voltage of the coolant a couple of times a year. If they had used cast iron instead of aluminum none of this would be necessary. And according to the PO, it lost an oil cooler to corrosion at about 1,000 hr. Supposedly there was an engineering change that solved that problem, but I inspect it annually as well.

Like you, I have heard good things about Deere.

Detroit Diesel marine 8v53s had aluminum heat exchangers. Not so good, so they all make mistakes. Take the Cat 3116 for example. Volvo however, seems to be very good at doing stupid things. And just keeps coming up with increasingly stupider (is that a word ?) things.

LarryM said:

Eric,

Sorry, but I'm going to have to throw a flag on that statement. The Volvo MD series marine diesels were designed and built for one thing, and one thing only, boats. Granted, later small marine diesels are often based on industrial or automotive designs, but some engines are definitely marine only.

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Larry I'm very glad to have been found wrong. WOW it looks indeed that you are right. That's wonderful. I remember the Albineer's Club where so many had these engines. Had no idea they were completely marine.
Another 100% marine engine is the 22hp Albin engine that powered the first Albin boats. It was designed as a marine engine and unbeliveably the 25' Albin boat was created for the engine.

There's two so there could be more. But wouldn't be surpprised if that was it.

Larry "decades ago" like about 60 years or more there were engines like Lathrop, Hercules, Redwing, Universal, Chris Craft, Nordberg, Kermath and I think even Chrysler was a true marine engine.

Ski,
I remember many tales of the MD Volvo's lasting 30+ years. Wouldn't that be a sure sign of a marine engine? Had to be built for it or they would never have lasted 30years. But re aluminum manifolds I agree. That's one of the big reasons I chose the Klassen engine for my boat.

Thank you LarryM.

My dad's Ingrid 38 had a Sabb diesel - I think they might be marine only.

But I think a lot of this confusion is about "lightweight" diesels, which are a tremendous challenge in the marine world. I know others here are not fans of David Pascoe, but I think his rule of thumb works just fine.

Those Volvo MD 1 , 2 or 3 were probably the last marine engines Volvo made.

With the decades of rule expansion by the Air Police of the world , the number of engine Mfg has declined , so except for large ship engines , most small boats with a 50-500hp need will be using marinizations.

Happily tho the engine guys are working hard to bring mechanical injected engines up to Air Police specs.


The commercials of the world are not happy with $1000 injectors and $10,000 brain boxes.

refugio,
I had a feeling another one would pop up.
I agree. I'm sure those Sabbs were 100% marine.

I don't however think "lightweight" has anything to do w it. Well one thing is obvious. The pool of diesels that get marineized are probably lighter weight as they come from applications where a light engine is more desirable. Don't want a monstrous pice of cast iron on a small tractor or in a sailboat. And of course lightweight is a good thing for non-trawler type boats. Most all the small marine diesels have aluminum manifolds. In this case lightweight is not good IMO.