Engine Choices

Hey All,
First off I am a Newbie.....I am considering my first boat purchase and the boat I am looking at I have found with one of 3 engines. It seems that a Volvo diesel is the most common, but they also are found with Yanmar, and Cummins engines. Knowing little to none about engines I wondered if more experienced members might provide insight into these brands. I appreciate any experienced insight into the pros and cons of either.....or doesn’t it really matter and my questions are there only because I know so little ???
Thank you
Keith
“ It’s not the speed that kills, its the sudden stop at the end!”

Look at the engine displacement not just the HP rating. Cummins would be my choice all things being equal.

PACA 1953 said:

Hey All,
First off I am a Newbie.....I am considering my first boat purchase and the boat I am looking at I have found with one of 3 engines. It seems that a Volvo diesel is the most common, but they also are found with Yanmar, and Cummins engines.

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I have had all three brands over the years & my favorite is Yanmar but the Cummins were the easiest to work on.(IMO)

they all will break eventually. so first thing is to look at is service and support for what your wanting to buy. the cummins would probably be the best for part availability/cost as well as support.

Which model of those engines--Example--a Cummins 6bt is more desirable than a Cummins 555.


https://boatdiesel.com/

It is a 6 BTA Cummins

PACA 1953 said:

It is a 6 BTA Cummins

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Excellent engine.

Lots of 6BTA's out there in various configurations. Some better than others. Be more specific: 250,300,330,370hp? CPL number from tag? Type of aftercooler, which injection pump?

PACA 1953 said:

Hey All,
First off I am a Newbie.....I am considering my first boat purchase and the boat I am looking at I have found with one of 3 engines. It seems that a Volvo diesel is the most common, but they also are found with Yanmar, and Cummins engines. Knowing little to none about engines I wondered if more experienced members might provide insight into these brands. I appreciate any experienced insight into the pros and cons of either.....or doesn’t it really matter and my questions are there only because I know so little ???
Thank you
Keith
“ It’s not the speed that kills, its the sudden stop at the end!”

Click to expand...

It might also be helpful for the forum members in-the-know identify any engines to avoid like the proverbial plague.

Volvo parts are very expensive and supply is very slow. Cummins are the best IMO.

I have a cummins 6bt 210 in my trawler.... The bt has a turbo and the bta an additional aftercooler. The more complex, the more things that can "break".... while they may be more efficient with the additional parts, you very well may have to replace or repair each of these additions. I just replaced my turbo. Personally, I would avoid the aftercooler for sure, and while the turbo gives a power boost with less weight, I'm not sure what advantage the aftercooler gives. Maybe someone can clarify that addition.

KenM said:

I have a cummins 6bt 210 in my trawler.... The bt has a turbo and the bta an additional aftercooler. The more complex, the more things that can "break".... while they may be more efficient with the additional parts, you very well may have to replace or repair each of these additions. I just replaced my turbo. Personally, I would avoid the aftercooler for sure, and while the turbo gives a power boost with less weight, I'm not sure what advantage the aftercooler gives. Maybe someone can clarify that addition.

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Aftercoolers cool, and thereby shrink, the output of the turbo so each "charge" of air has more air per volume. The turbo compresses/heats, and thereby, expands the air, while the aftercooler cools, and thereby, shrinks it, so more actual air is delivered with each intake stroke.

KenM said:

. Maybe someone can clarify that addition.

Click to expand...

More HP for those that need it and pretty well required for new build emissions acceptance in this era.

Most diesels are reliable if 3 cubic inches of displacement or more are used to produce 1 hp at cruise.

At this low power level turbos ,after coolers and electronic injection are not required , except for the Air Police.

Thank you All for your input. So if one boat had a Cummins vs the other two, all other things the same, would the boat with the Cummins be worth a significant amount more...say$ 20,000 or so more?

Although its kind of silly to comment on the relative worth of three engine brands, when current condition is the most important factor, here is how I would rate the three engines in dollar terms when new:


Cummins: Base
Yanmar: $2,000 less
Volvo: $5,000 less


The rating is based on potential problems, cost of parts, and availability of competent technicians.



I actually made that decision some years ago when buying a new Mainship 34T. The Cummins was $10,000 more than the Yanmar and Tony Athens said no way is the Cummins worth that much more so I bought the Yanmar version. The big $ difference was probably due to Mainship's long standing relationship with Yanmar and their desire to block the competition.


It was a good decision.



David

I will reiterate from experience with my last boat...Volvo Penta parts are very expensive. The units can be particular and, IMO, require a technician that has experience with the issues of your specific model. Think of maintaining an European vehicle.

For example, I had a D4-260 with a DPH-A drive. VP was on the DPH-D (fourth version) of that drive when I sold the boat. Our very proficient technician helped us avoid problems he saw in other boats through a specific maintence plan, which was very reasonable - but not in the manual.

Aside from that, I enjoyed the efficiency and performance of the power package. It never left us stranded or limping home. It also sold quickly when the time came. Maintenance is KEY.

Good Luck

While I would pick the Cummins first and Volvo last, the difference in the cost of used boats is likely not the make of the engines, maybe the hours on the engines, but most likely the condition of the boat in general or the owner's situation and boat location. Don't get so focused on the engines make that you miss the leaking cabin roof.

Ted

Keith,
All good advice, especially OC Diver. Overall condition, regular past maintenance, and hopefully having maintenance records to show what has (or has not) been done to the boat (not just the engine) are important.
For a used boat, I don't think the brand of engine would have much (if any) affect on the asking price. However, as stated above, the brand MAY affect the desirability of the boat, and for some buyers may be a deal breaker.
Having owned both Volvo and Cummins (6BTA), I really like my Cummins and would not own another Volvo. For Volvo, I found parts were hard to find and sometimes had to be shipped from Europe, and they (Volvo) did not stand behind their product (long story there). Twice, I had trouble even getting a mechanic who would come look at it.
As stated, on the 6BTA, regular aftercooler maintenance (done the right way) is critical for successful long term operation. Plan on removing the aftercooler for servicing every 3 years (min.). This time frame can be extended if the engine is regularly freshwater flushed after use (maybe up to 5 years). All of this applies to the seawater cooled aftercooler (which is the most common I am told).

Personally, I would not rule out a boat with a Yanmar, especially if the boat was in good condition with a record of good maintenance having been performed.
Good luck in your search,
Tom

Open-d wrote;
“It might also be helpful for the forum members in-the-know identify any engines to avoid like the proverbial plague.”
There are none.

Most here would say buy Cummins but is seems it’s mostly that it’s a decision powered by vogueness among boaters. You appear to know what you’re talking about if you say Cummins Cummins Cummins. God’s boat in Cummins powered.

But it’s just a brand.

We mostly buy boats by using much more intelegence and objectivity. It seems the choice for engines is 99% about what brand you choose. For a boat we have many features we mull over till we can’t walk straight. For me I choose mostly because I wanted glow plugs and didn’t want aluminum for the exhaust manifold. I had had a Yanmar before and there was some corrosion issues. We were moving to Alaska and starting dependably in Alaska was a big gotta have for me. But most if not all engines have evolved where those two features aren’t available or need/wanted anymore. But there must be other features that are different and desirable on non-Cummins engines. I haven’t shopped for about 15yrs so I don’t know.

But if nothing else the biggest feature for me was the size/power of the engine. My favorite brand was Izuzu but power choices were limited to too much or too little power. All the brands had a wide choice of engine sizes then. Is that not true anymore? There are a few choices to make like rotation and bell housing fit but why not choose engines a bit more like choosing boats? There’s 10-15 popular boats to choose from. And there’s almost that many engines. The Vetus line alone has many different engine brands (mine among them) and a very wide range of power options. If I’d ask why dosn’t anybody mention Vetus I’d prolly hear about special manufacturer pricing. But what’s that got to do w choosing an engine for an old boat?

Price. But we don’t get zero’ed in on one brand on boats. And guys regularly buy boats that are universally over priced due mostly to their popularity and boats that are not so popular for cheap .. relatively.

Do most all new engines have aluminum exhaust manafolds now. Surely there must be some w cast iron manafolds obviously more suitable for trawlers.

Thank you all again! This is all such great information So on the subject of records, should one expect a responsible owner to have all repair and maintenance records? If so one should expect those to be shared if present? Also what about the “Boat History Reorts”? Is this something that you would check?

Boat maintenance records are nice, but they don't tell you everything. While maintenance is important, how the boat was run may have a much bigger impact on condition. Depending on the engine, if the owner ran the boat at or near wide open throttle most of the time, may more impact on the engines than how often the oil was changed. As part of the survey, you definitely want to have oil analysis done on engine(s), transmission(s), and generator.

Ted

I know nothing about engines. I will say that my last sailboat had a small Yanmar in it that seemed to be just about bulletproof. However a small 54hp engine is different than a 300hp engine. My ignorant experience with my Yanmar doesn't really inform me about potential experiences with larger Yanmars.


I current have a Cummins in my boat. 380hp 5.9l QSB. Yeah, I like it. However, this is the second engine of that type in my boat because the first one was killed off by a Cummins mechanic while "fixing" it. Worked out fine, I got a new Reman engine out of it.


Based on my experience, one might assume that Yanmar good, Cummins bad. However I don't see it that way at all. As others have said, the value of a boat is based on a lot more than simply which engine is in it. I would shop the boat first, then look at engine brand 2nd. A well maintained boat with a well maintained Volvo engine would be MUCH more attractive to me than a poorly maintained boat or a boat with a poorly maintained Yanmar or Cummins engine.

I don’no Dave.
I think I’d hafta buy quite a lot of engines before having to huck out a new just purchased engine.

Gosh I dislike all three with Cummins the one I dislike least. My choice would be Deere.

Fish53,
Do they have cast iron exhaust manafolds?
How high can they jump?

Since they have long ago quit building actual marine engines w the flywheel in the front ect ect we’re stuck w tractor, truck engines ect and they aren’t even designed to run under the same loads that marine engines do. It’s no wonder the available engines aren’t ideal.

I'd strongly advise getting your "forum education" at BoatDiesel.com. And while here, pay attention to Ski, who is real and respected professional mechanic.

Generally agree with everything mentioned. There are some lobstermen that swear by their Volvos. 6bta is a great engine and Cummins remans are a great deal. There was one of the bigger Yanmars that had head issues - Well documented on boatdiesel. Avoid peninsulars if there are any left out there.

Where will you be boating? We have had Volvo in FL and they were just not cooled well enough fot our water temps. Cummins except 555. Especially the newer ones. Beware parts availability and cost on both Yanmar and especially Volvo. Even here in Ft Laud boating service capital of the world LOL

It’s like you guys are getting paid to bash Volvo.