Volvo or Cummins?

My search for a nice (mid 90's+) 42 or 46 Grand Banks CL continues. Been on 7 boats from Great Lakes to MA down to FL. First comment is I can't believe the way some of these boats have been neglected. I'm talking real bad.....but I digress.
I did come across a well kept 1995 boat with a single Volvo TAMD 102D, 428HP. Broker called it commercial grade rated for 30,000 hours. Don't know about that but guy on boatdiesel said I will have problems getting parts. I did find parts on line but wonder about 10 years down the line? Can't imagine having a chuck of money invested in a boat and not being able to get parts!

Next boat is newer 2003 and has twin Cummins 6CTA8.3M3, 450HP. Lots of power for a 42 so my fuel cost will be high but I think better for parts availability don't you think? Both engines have wet sleeves for rebuilding but does that mean you could rebuild the engines in place and not remove the engine form the boat?
Thanks.

Working from the bottom up of your list of questions:

Recreational marine engines with the possible exception of DDs rarely get rebuilt and if they do almost never in place. I don't think you can drop the crankshaft or pull the camshaft of a Yanmar, Cummins, Cat or Volvo in place and you certainly can't line bore the block.

Fuel costs will not be high on the twin Cummins boat unless you make it that way by pushing the throttle open. Yes the twin engine boat requires two engines to be turning rather than one engine on the single. That will consume more power in parasitic losses for the twins. But the single engine will be running faster to make the same power (assuming both boats are going the same speed) and that requires some additional parasitic losses.

Net, the twins will require more fuel but not much, maybe a half gph in total at low speeds. At higher speeds, maybe the same.

The Cummins 6CTA is a very solid engine and parts are available everywhere and priced reasonably. Not sure about the Volvo but dock talk says the Volvo will be more expensive.

Finally although you didn't mention it, you will have better engine access for the single and more room for genset, extra batteries, even an active stabilizer system if you want to install one. But I have been in the engine room of a twin engine GB42 and engine access was quite acceptable and normal engine room stuff like batteries and generator fit in just fine. The GB46 would be even better.

David

Volvos are solid engines, with a well deserved reputation for reliability...and expensive parts.

Cummins, in my opinion, represent the better value. They are proven engines, have excellent support worldwide (factory and aftermarket) and are easy to work on.

What he said, especially expensive parts!

Actual fuel use will be determined by YOU and how you run the boat. If you plane the boat it will use fuel, lots likely. Engine won't matter much.

If you run the boat at displacement speeds it will use hugely LESS fuel.

How you use the throttle will determine the fuel use. True there may be slight differences between engines in efficiency but that will be on the order of a few percent, maybe up to 5% or 10% which is for most of us not a deal breaker. Many people have engines that can plane their boats but chose not to and have very acceptable fuel use.

As for rebuilding in place that is determined more by the boat than the engine.
How much head room is there above the engine? How much stuff must be moved/removed to gain access.

To be serious the odds of a cylinder liner replacement are pretty low. Even head work is likely low.

I don't know how old the Volvo design is but the Cummins dates to about 1985 or thereabouts with lots of upgrades by Cummins to that engine series.

The same cannot be said for the Volvo in question even though I expect it is a good engine.

Cummins has a good history of supporting the older engines although not all is perfect even for them. Volvo is getting a history of not supporting older engines so that has to be accounted for and that is why the comments.

Sometimes parts for older engines are picked up by other mfgrs such as Mahle, Federal Mogul or the like and extend the useable lifetime.

Often the base engines are good for long term service but it's the other stuff that can cause trouble. Even the best and most robust engines can be damaged by lack of mtce., overpropping causing overload especially if planing use is done.

Propping For another post maybe.

Cummins, it isn’t even close.

Smallish boat diesels seldom get complete rebuilds in the boat. Pull the top and do the heads, sure, but getting to the crank or reinserting the cam in the boat probably will not happen.

The quality of the rebuild will be vastly improved if you bite the bullet and pull the engine. It will be about $2,000 but it is money well spent. Travel time and truck time which will be charged for an 'in boat" rebuild will easily eat up the cost of pulling and replacing the engine. Not to mention that this gives you a great chance to do other bilge maintenance.

pete

I've owned or used boats with both Volvo and Cummins engines. Both are good reliable engines but as has been previously stated, Volvo is very, very proud of their parts. They are pricy and sometime hard to find. Some Cummins diesels are used in Ram trucks and some parts may be available through your Chrysler dealer (I know the 6BT parts are); this keeps them cost effective. A bigger question is single vs twin and there is a whole discussion chain on this site talking about that. Good luck with your call and let us know.

Another vote for Cummins, especially regarding parts cost and availability.

Had a single 6 C 450 HP Cummins in my boat. As mentioned, rock solid, great parts availability, and reasonable parts prices. Can't speak to this specific Volvo, but given a choice between the 2 manufacturers, I vote Cummins.

Ted

Comodave said:

Cummins, it isn’t even close.

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Yep. Nuff said.

Cummins all the way. The 6CTA is one of the best "small" marine diesel engines out there!!!!

Another vote for Cummins (that model you are looking at are a great engine, you can get good parts and tech assistance worldwide from Sbmar, the Tony Athens website).

Also another vote for finding a 46 if you can (rather than a 42 - there is a heap of extra room on the 46, both length and beam).

Hamish.

What spare parts are you expecting to buy? You gunna rebuild your engine?

Take care of your fuel and general maintenance items and likely your engine won't need anything other than filters, oil, zincs and impellers until the day you die.

That single engine Volvo may fit your needs better than a twin. Before you make a decision based on scare tactics, go to Alibaba and price out buying a whole suite of spare parts that you might want to keep on hand for distant cruising (filters, injectors, fuel lines, impellers, zincs, etc.) and plan to repair things yourself.

Or if you source your spares in America, can you buy bulk oil filters that are compatible, from AutoZone or online? If not, are Volvo factory parts really more expensive than having to buy TWO sets of spare parts and lube oil for those twin Cummins?

So if the Volvo and the Cummins are all in good shape, then your decision should be more around which boat is better shape, which engine config fits you better and which seller will negotiate lower.

Now, being subjective, I would say that if you plan on the bulk of your cruising to be at slower speeds, then go with the single and run it harder - it's healthier for the engine

makobuilders said:

What spare parts are you expecting to buy? You gunna rebuild your engine?

Take care of your fuel and general maintenance items and likely your engine won't need anything other than filters, oil, zincs and impellers until the day you die.

That single engine Volvo may fit your needs better than a twin. Before you make a decision based on scare tactics, go to Alibaba and price out buying a whole suite of spare parts that you might want to keep on hand for distant cruising (filters, injectors, fuel lines, impellers, zincs, etc.) and plan to repair things yourself.

Or if you source your spares in America, can you buy bulk oil filters that are compatible, from AutoZone or online? If not, are Volvo factory parts really more expensive than having to buy TWO sets of spare parts and lube oil for those twin Cummins?

So if the Volvo and the Cummins are all in good shape, then your decision should be more around which boat is better shape, which engine config fits you better and which seller will negotiate lower.

Now, being subjective, I would say that if you plan on the bulk of your cruising to be at slower speeds, then go with the single and run it harder - it's healthier for the engine

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This is an excellent post!! I think you need to zoom out. You are somewhat not comparing apples to apples. If it were a Single Cummins versus that single Volvo, I would say go Cummins. But now you are getting into the whole "Single versus Twin" debate. So the choice in which boat to buy isn't simply Cummins versus Volvo. It is also Twin versus single. I would be curious to know if it were twin Volvos versus a SIngle Cummins what the opinions would be.

Bottom line....if it were only engine manufacturer choice. I would pick Cummins. But your "problem" is a bit more complex than that.

Baker, you're right. Let's not sink to twins versus single. But what I was hearing in the posts was that twin Cummins are better than a single Volvo, because of price of parts and repairs.

As far as I can tell, a 428hp Volvo Penta TAMD 102A is a special light duty recreational rating. What is the rpm? The heavy duty commercial rating would be @ 1800 rpms.

So beyond the VP versus Cummins debate, the bigger issue IMO is: why is the yacht broker blowing smoke your way?

The whole idea of low power diesels is that outside of valve lash, you really don't work on them much.

Belts, filters, hoses, impellers, valve cover and injector gaskets.

Northern Spy said:

The whole idea of low power diesels is that outside of valve lash, you really don't work on them much.

Belts, filters, hoses, impellers, valve cover and injector gaskets.

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I don't know about the Volvo...but the Cummins wouldn't really be considered low power. It is close to 60hp per liter. That is pumped up pretty good. Also, you need to add to your list....turbos...aftercoolers....fuel coolers....transmission coolers....heat exchangers. All things that could really screw your world if something goes wrong. Your list would be appropriate for a Lehman though as it is certainly a low powered engine. Interesting to note....the B series Cummins and the Ford Lehman are almost identical in displacement. An NA Lehman is 120/135hp. An NA 6B Cummins is 115hp. The highest power of mechnical B series version is 370hp. And in the common rail QSB they crank it up to 425hp...all with the same 5.9 liters displacement.

Appreciate the great info guys. Here is a little more info. The single Volvo boat is a 46 coupled to a Hundested gear and variable pitch prop. Stated cruise is 1100 rpm for 8.5 kts and fuel burn of 4.5 gph. Great engine access as you might imagine. I did speak to a Hundested rep and he quoted a rebuild for the unit at 40,000 hours so I am good with that system and parts available too. Boat has bow & stern thrusters and is in really great shape. You can sense someone had some pride here. I was really interested until I heard that volvo parts could be a problem. But now Makobuilders is telling me a little different. Never thought of Alibaba.
The twin Cummins is a 2003 42 footer. I have not been on board yet but it looks sweet and it is priced much more. Per the posts here I don't think I could go wrong with this boat/engines if it really is as good as it looks.
The Admiral and I are transitioning sailors (25 years) coming from a 36 ft Catalina. Either boat is a big step up. We will cruise Lake Michigan and other lakes and maybe do the loop one day. If I could be confident in parts for the volvo I think it would be our first choice though. For the difference in price I could afford a bunch of spares and I'd have a room to stash them! I am still hesitant. In 10 years when I sell the boat will another prospective buyer be wondering about parts availability? Will I be able to sell the boat? Or should I be safe and go with the newer Cummins? Keep the comments coming. You all are very helpful. Thanks.

Hi Pat T,

One further thought from me.

All the 46s I have ever seen are twins, and so I am not sure that a GB46 with a single engine is a prevalent/popular configuration? There is nothing wrong with that of course, but it may make it possibly harder to sell when the time comes for you to move on?

In my earlier post I said choose a 46 over a 42, I think for my part now knowing the competing boats’ specs better I would personally be inclined to the 42 you mention because (a) I do prefer the specific engines (b) it’s a fair bit newer and (c) its a twin.

Good luck, GBs are great boats (that is a very biased opinion, BTW).

H.

Too bad that isn’t a single C series Cummins in that 46. That would be dreamy. But I do think the parts thing is overblown for the Volvo. I have never heard of anyone sitting around going nowhere because they can’t get parts. I do believe it will affect resale value down the road simply because the bad rap Volvo gets...deserved or otherwise.
A question no one has asked...is speed important to you at all?? That 42 with those engines should be able to get up and boogie. Obviously at a cost in fuel. Not sure what year GB went to planing hulls versus semi. But even if it is semi, you should be able to cruise in the teens easily with that power if you so desire. It might come in handy in the Great Lakes for making Port befit sundown.
One final thought and this is totally opinion and emotion. The GB46 is the perfect size. It just seems from a design proportion perspective, it is perfect...especially in the Europa. The 46 Europa is quite possibly the prettiest boat on the planet.

Even if the Volvo runs fine the whole time you own it, I wouldn't buy a boat with one simply because of resale. Down the road, anyone looking to buy your boat will be asking the same question. And they will get the same responses. Volvo has earned such a bad reputation around long term parts availability and cost, that lots of people won't even get past a listing description when they see a boat has Volvo engines. So just as you may reject an otherwise good boat just because of it's engine brand, so will the next person looking to buy your boat. And you will find your prospects all buying other boats.

I'd try to get an idea from the previous owners of what the fuel consumption difference is at lower speeds. If it's not much, take the twin Cummins. They'll likely have better resale. Parts has already been covered.

Cruising slow, either set of engines will be well below the power level it can output continuously for a very long time. But with the Cummins twins, you'll have the option of taking advantage of the semi displacement hull and making some speed without beating the snot out of the engines. The single Volvo probably won't get far enough above hull speed to be worth ever trying unless you're at WOT. FWIW, the GB49 currently sitting next to my boat has twin 375hp cats and those are apparently good for 18 kts at WOT, so fast cruise around 14 or so. Twin 450s in a 42 should be able to fast cruise at 17 - 18 and I'd expect 22 or better at WOT.

Pat T said:

Appreciate the great info guys. Here is a little more info. The single Volvo boat is a 46 coupled to a Hundested gear and variable pitch prop. Stated cruise is 1100 rpm for 8.5 kts and fuel burn of 4.5 gph. Great engine access as you might imagine. I did speak to a Hundested rep and he quoted a rebuild for the unit at 40,000 hours so I am good with that system and parts available too. Boat has bow & stern thrusters and is in really great shape. You can sense someone had some pride here. I was really interested until I heard that volvo parts could be a problem. .

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That sounds like a very interesting vessel. Suggest you keep chasing it. As noted by Spy and others, the base engine should not be much of a concern. The question is the parts and pieces termed marinization bolt ons. Looking this engine up on boat diesel may prove helpful as well as cold call a Volvo Penta shop.

The bigger Volvos are better than the smaller ones as they tend to be intended for commercial service. And sounds like a very interesting boat with the CPP and single engine.

I don't know what the parts situation is for that Volvo, never did much work on them. Suggest you call a dealer and ask if parts like cylinder kits, after coolers, heat exchangers, oil coolers, manifolds and turbos are still available. And for how long that situation is likely to remain.

Worst case is to buy the Volvo boat and if it poops completely, replace the Volvo with a modest rating Cummins C series.

For my new build 14yrs ago I bought a used 450C with 1200hrs on it. I have added 2800hrs since and it has basically been flawless. Total cost of the engine used was $14k, cheaper than the parts to rebuild that Volvo (probably, don't quote me on that).

Good chance that if running at 1100, that Volvo will last a long time until something like a cooler rots out.

I don`t see how to avoid the single/twin issue when the 2 boats under consideration raise it. You already know the joys of a single,albeit probably without thrusters,but boats with can unexpectedly be without. I suggest you drive a boat with twins and see if, like me, you appreciate what they can do.
More generally,I`d say go Cummins. And assuming you can live with 42ft instead of 46,which coming from a 36ft sailboat, should be enough. But check out the executive sleeping berth to see if it suits, that could be a factor.

Good discussions guys. To answer a few of your questions: The Volvo is a TAMD102D not 102A and per my research classified as rating 3, 428 HP at 2200 rpm.

Ski, great idea on swapping out for a Cummins. If I am not mistaken the HP of the 8.3L is similar to the Volvo. A quick search and one could be had in the 20-25K range rebuilt. But how much to engineer and install? Seems doable though and removing a single engine from a 46 has got to be easier than pulling one from a twin 42.

Bow thruster on the 46 is hydraulic so I am assuming more reliable than an electric?

And as far as speed goes remember I am past sailor. If we were sailing 6 kts I was doing well. Hull speed was about 7.2 on my last boat. So I would be tickled pink to be going above 8 kts especially in the exact direction I want to go! Can't wait to get a boat but so much to learn & be concerned about. Thanks for the education.

CPP setup coupled to a volvo would nix it from consideration from me. CPP is great in theory and practice....If you have deep pockets and time to wait. Who do you know that would work on CPP when (not if) you have an issue?...Never mind the Volvo.

Agree with you SOF. A key question would be what CPP spare parts go with vessel...