Yanmar 3YM20 vs Beta 20

[stormalong]

Originally Posted by Dockhead

Probably the result of a badly conceived installation, but I have heard of this, so must not be a one-off situation.

Many Yanmars, including my 4JH3 HTE, have the water pump">raw water pump in a very awkward position. This is because the raw water pumps are GEAR DRIVEN, rather than belt driven.

Mine is awkwardly mounted right in front of the starter motor, so close you can't get an impeller puller in there, and if you forget to shut off the sea cock before removing the impeller cover, you've just bathed your starter in seawater (don't ask me how I know ).

But gear driven is really nice, plus being right at the bottom of the engine, they are always full of water, so leaving a sea cock accidentally shut or getting seaweed in the strainer doesn't destroy the impeller.

There are pluses and minuses, so you pays your money and takes your choices!

I saw this from as extensive thread on a different discussion board a few years ago. The pictures posted showed what looked like a standard engine mount and more than one participant in the discussion had the issue. The discussion was about how difficult an impeller change would be in an emergency situation.

The point that I was trying to make is if that engine was designed for marine use as Yanmar claims about it's engines, how could they come up with such a poor design.

BTW, I have owned three Diesel engines. A Westerbeke (Mitsubishi), a Perkins and a Beta (Kubota). All three have gear driven raw water pumps. My thinking is that this is the norm and belt drive is unusual. I could be wrong as this is anecdotal.

[Dockhead]

Originally Posted by stormalong

I saw this from as extensive thread on a different discussion board a few years ago. The pictures posted showed what looked like a standard engine mount and more than one participant in the discussion had the issue. The discussion was about how difficult an impeller change would be in an emergency situation.

The point that I was trying to make is if that engine was designed for marine use as Yanmar claims about it's engines, how could they come up with such a poor design.

BTW, I have owned three Diesel engines. A Westerbeke (Mitsubishi), a Perkins and a Beta (Kubota). All three have gear driven raw water pumps. My thinking is that this is the norm and belt drive is unusual. I could be wrong as this is anecdotal.

Well, if that is inherent to the engine design, then it is very poor design indeed.


Yanmar is a great company making great engines, but they have produced a few lemons and not every single design solution is perfect.


I think it's silly to be a fan boy of any one maker.


I owned a Westerbeke-marinized (with belt drive raw water pump!) Perkins 4-108 which gave 20 000 hours of service (!) without ever even having the head off. It had its own design defects (totally dysfunctional oil sealing for one), but what a great engine. Nothing broke, literally, and it never failed to start, not once, in 20 years of hard use, and it was already old when we first bought it.


I have never owned a Beta, but everyone I know who had had one has been extremely pleased with it.


Diesel engines have been around for more than 100 years and the technology is very well worked out. I think few of them are actually bad -- just one infamous model of VP comes to mind, and perhaps the early Yanmar 4BY common rail engines which were lemons -- so these are among the most reliable items of gear we have on board.

[Q Xopa]

Originally Posted by Dockhead

There is no such thing as "industrial rated"


With marine engines, "recreational rating" only refers to the rated power. The very same engine may have different rated power depending on whether the power is used continuously or not. Hardly relevant to us since in a sailboat you will very rarely use full power and never for extended periods of time.



Yanmar and Kubota both very durable, very good, Japanese engineering made by companies with huge engineering resources and a century, give or take, of experience building millions of diesel engines.

Yes agreed about rated power. These HP and Torque numbers are done at 'Standard' atmospheric conditions.

Also agree that they are both very good durable Japanese engines.

As previously stated I myself am a happy Yanmar 4JH4-TE owner.

Rod is also correct that Yanmar make both 'Pleasure/ Recreational' and 'Industrial/ Commercial' rated engines. These terms get intermixed by different manufacturers. Eg Cat call 'IND A' what others call Rating 1 – Continuous duty Commercial. But this is the same thing and it is the highest rating, basically meaning the engine can be run at Full power for unlimited time (obviously up to it's ultimate TBO life).

There are various 'lesser' commercial rating, then Recreational/ Pleasure rated engines. This essentially means- the engine is rated to run less than 300 hours annually and max 1 hour in 12 at max continuous rating.

Light commercial duty engines are built to run between 800-1000 hours a year. They are still only meant to run full power 1 hour in every 12.

One ref- Engine Ratings - CVS Pentapower

As you also correctly say this may or may not mean anything relevant in practice?

But one would assume the 'Commercial' engines are built to be more durable than 'Pleasure' engines.

If I am not mistaken, the Yanmar 3YM20 is a Pleasure rated engine and the Kubota D722 is a Commercial rated engine. Maybe something, maybe nothing. Take of that what you will.

[Dockhead]

Originally Posted by Q Xopa

Yes agreed about rated power. These HP and Torque numbers are done at 'Standard' atmospheric conditions.

Also agree that they are both very good durable Japanese engines.

As previously stated I myself am a happy Yanmar 4JH4-TE owner.

Rod is also correct that Yanmar make both 'Pleasure/ Recreational' and 'Industrial/ Commercial' rated engines. These terms get intermixed by different manufacturers. Eg Cat call 'IND A' what others call Rating 1 – Continuous duty Commercial. But this is the same thing and it is the highest rating, basically meaning the engine can be run at Full power for unlimited time (obviously up to it's ultimate TBO life).

There are various 'lesser' commercial rating, then Recreational/ Pleasure rated engines. This essentially means- the engine is rated to run less than 300 hours annually and max 1 hour in 12 at max continuous rating.

Light commercial duty engines are built to run between 800-1000 hours a year. They are still only meant to run full power 1 hour in every 12.

One ref- Engine Ratings - CVS Pentapower

As you also correctly say this may or may not mean anything relevant in practice?

But one would assume the 'Commercial' engines are built to be more durable than 'Pleasure' engines.

If I am not mistaken, the Yanmar 3YM20 is a Pleasure rated engine and the Kubota D722 is a Commercial rated engine. Maybe something, maybe nothing. Take of that what you will.

Well, we're talking about different things. You seem to be saying that some engines are built to lesser duty than others. That is certainly true of generators, and may be true of propulsion engines, but that does not follow from these ratings. If you read the CVS Pentapower article you linked, they are not talking about this, they are specifically talking about POWER ratings. So what duty at what rated power, and the same engine might have all four ratings but at different stated power outputs.


I doubt that the 3YM20 is lighter built than the Kubota. A variant of this engine, the 3YM27, is also sold in Yanmar's line of commercial engines. It is similar to the 3YM30 but rated at 27 horsepower instead of 30 and at lower RPM.


The 4JH3 engines were sold for commercial duty on commercial fishing boats, as well as for pleasure boats. There is even a "trolling lever".


The fact that an engine is sold as a "pleasure boat" engine doesn't necessarily mean it's lighter built -- in many cases it may just be rated at a higher power output than would be suitable for continuous duty.

[Q Xopa]

Originally Posted by Dockhead

Well, we're talking about different things. You seem to be saying that some engines are built to lesser duty than others. That is certainly true of generators, and may be true of propulsion engines, but that does not follow from these ratings. If you read the CVS Pentapower article you linked, they are not talking about this, they are specifically talking about POWER ratings. So what duty at what rated power, and the same engine might have all four ratings but at different stated power outputs.


I doubt that the 3YM20 is lighter built than the Kubota. A variant of this engine, the 3YM27, is also sold in Yanmar's line of commercial engines. It is similar to the 3YM30 but rated at 27 horsepower instead of 30 and at lower RPM.


The 4JH3 engines were sold for commercial duty on commercial fishing boats, as well as for pleasure boats. There is even a "trolling lever".


The fact that an engine is sold as a "pleasure boat" engine doesn't necessarily mean it's lighter built -- in many cases it may just be rated at a higher power output than would be suitable for continuous duty.

Yes agree with what you are saying.

Yes we are talking about slightly different things as, I dont think I explained well enough or you mistook my meaning.

Your example of the same engine 'derated' to a lower 'full' power but for longer. Yes exactly thats saying the same thing a slightly different way.

Conversely, two engines with similar output ratings but one rated for Commercial and the other for Pleasure. It follows that it is likely the Commercial rated engine is designed and built at least as well, for a longer harder service. As you say there is probably not much in it.

It also follows, as suggested in an earlier post, that the Betas are less durable because of how the parts are cast. This was the point I was countering.

The link I posted had the definitions for the different Commercial and Pleasure duty cycle ratings.

[Dockhead]

Originally Posted by Q Xopa

. . .It also follows, as suggested in an earlier post, that the Betas are less durable because of how the parts are cast. This was the point I was countering..

Those Kubota engines are super tough, super simple workhorses. However they cast the parts, there is no question that they are very durable, certainly no less durable than the Yanmar if not more so.



When I had a mooring on the Hamble River, I was well acquainted with the Hamble River water taxi operator, who put huge hours in his little fleet of watertaxis, on the order of 2000 hours a year IIRC. He used Betas, probably this very engine. He got over 10 000 hours out of them and they never broke. Over 10 000 hours they just started to gradually lose compression and oil pressure and he would change them out as he couldn't afford unexpected down time. He swore by them. Don't think he took all that good care of them, either.



Now funny enough, he eventually switched to Chinese engines. He said he could get 6 000 hours out of these, but at 1/3 the price, so the numbers worked.

[Q Xopa]

Originally Posted by Dockhead

Those Kubota engines are super tough, super simple workhorses. However they cast the parts, there is no question that they are very durable, certainly no less durable than the Yanmar if not more so.



When I had a mooring on the Hamble River, I was well acquainted with the Hamble River water taxi operator, who put huge hours in his little fleet of watertaxis, on the order of 2000 hours a year IIRC. He used Betas, probably this very engine. He got over 10 000 hours out of them and they never broke. Over 10 000 hours they just started to gradually lose compression and oil pressure and he would change them out as he couldn't afford unexpected down time. He swore by them. Don't think he took all that good care of them, either.



Now funny enough, he eventually switched to Chinese engines. He said he could get 6 000 hours out of these, but at 1/3 the price, so the numbers worked.

Yes I agree, that has been what I have seen and heard so far.

But I am not an expert like others posting with less opinion of these motors.

Not that I am saying the Yanmars are bad either. I agree with you they are both respectable motors and companies.

I heard the comment earlier about the Yanmar dealer network aceess to parts. Like another previous poster I was just in Fort Lauderdale at an agent chasing parts for my 4JH4. Lots of the common parts I requested had to be ordered in.

I order most parts online, and get them shipped, because it is slim pickings in Panama. But frankly going to a large agent in a big boating area doesnt seem to be much better. So Im not convinced about the dealer network touted advantage.

[rla]

I've fitted several Yanmars and been involved in their lives... most of them quite short !!
Dropping valves , breaking con rods and rotting as an anodic heap of dissimilar metals.
yes there are old GM engines I know that are years old and done thousands of hours but not YMs. Beta have a much better reputation and the lads that started the firm used a lot of their Lister engine previous experience and a lot of common sense, to make Beta (Kubota and John Deere) engines made for the marine job.

[nmccubbin]

We have over 1000 hours on our Beta 60
No issues
It starts First bang, even when in the Arctic. We have used the heaters once only, to test them
Mechanically quiet and no black smoke staining the hull
The SSCA database shows much better reliability than Yanmars, but over a smaller user base

The above comments make sense and show diversity
There is not absolute guarantee but on balance I would go for Beta

Definitely avoid Volvo

[Talbot]

My Priviledge 37 cat had 3GM30 Yanmars when I got her. I looked at using the beta 35, but went with the 3YM30 in the end. I also got new saildrives (SD20)as they can also be a problem.
The 3YM30 is a very different beast from the old GM. The fuel consumption is significantly improved, they are much less vibration, and service bits are MUCH easier to access.

They are also lighter than the beta. (important on a cat).

The beta saildrive looks much more agricultural.

Kubota parts are easy to get worldwide, but the Beta engines also have bespoke beta parts which - if you are going long distance - is a major decider.

[Pete the Cat]

I get a little tired of this “you can buy tractor parts argument” that Beta uses to sell their engines. As has been stated, it is not the standard parts on tractor blocks of marinized diesels that routinely cause problems. It is the “marinized” parts that these folks engineer and add on to the tractor engine that are the problem. Westerbeke “marinized” small diesels with raw water/freshwater systems and exhaust arrangements and replaced the solenoids and starters with ABA compliant substitutes And pioneered a business. As someone who has cruised for a few years, those “Marinized” parts are the weak link and you will not find them offered by the block manufacturers or tractor dealers. I repowered with a Yanmar 1000 hours ago in it has been flawless. The metals in it are built for salt environment. No zincs required. I serviced the exhaust elbow of my new engine at 1000 hours and it was indistriguishable from new-it is that clean burning. That suggests the quality of an engine designed for the function-not one cobbled from a collection of parts put on a tractor block. I recognize and appreciate that Beta is trying to bring better customer attention and service to the recreational marine industry—and their competitive pressure on big names like Yanmar and Volvo, but there is a reason that the boat manufacturers and charter boat operators generally use Yanmar engines. When you actually have to rely on their longevity and parts availability world wide, there is a choice. As for folks resisting common rail-I recall the same arguments when cars went from the inefficient and trouble prone mechanical carburetion schemes to electronic ignition and fuel injection. I suppose that many of you are out there with your Time honored sextants and RDF’s finding your way, rather than succumbing to the unreliable GPS nonsense. Just another view.

[ljones]

Both engines are reliable so the choice depends on parts availability and cost, local and worldwide service availability, and mounting/fit considerations.

I recently sold my Victory 35 catamaran that had a Yanmar 3JH2E engine. During 20 years of ownership, (approx 3000 hours) the only maintenance was oil/filter changes, replacing the motor mounts one time, replacing the exhaust elbow once, cleaning the heat exchanger, and repainting the engine. It always started on the first crank over, never smoked, and had excellent fuel economy.
My only complaint was that the water pump impeller was difficult to access and change— partially remedied by installing a Speedseal cover plate. In summary, a very reliable, easy to maintain engine. Deaton Yacht Services in Oriental, NC did some of the maintenance and they are terrific. Parts availability and prices were fine, although I never had to purchase any major parts.

I have several friends who repowered with Beta engines and they seem satisfied with that choice. I would be leery of buying parts from a tractor dealer because of the “marinized” issue.

[Firefly44]

for what it's worth, I can confirm that my 3YM20 is NOT common rail and that the water pump is very accessible for impeller change....

Dave

[Dockhead]

Originally Posted by Pete the Cat

I get a little tired of this “you can buy tractor parts argument” that Beta uses to sell their engines. As has been stated, it is not the standard parts on tractor blocks of marinized diesels that routinely cause problems. It is the “marinized” parts that these folks engineer and add on to the tractor engine that are the problem. Westerbeke “marinized” small diesels with raw water/freshwater systems and exhaust arrangements and replaced the solenoids and starters with ABA compliant substitutes And pioneered a business. As someone who has cruised for a few years, those “Marinized” parts are the weak link and you will not find them offered by the block manufacturers or tractor dealers. I repowered with a Yanmar 1000 hours ago in it has been flawless. The metals in it are built for salt environment. No zincs required. I serviced the exhaust elbow of my new engine at 1000 hours and it was indistriguishable from new-it is that clean burning. That suggests the quality of an engine designed for the function-not one cobbled from a collection of parts put on a tractor block. I recognize and appreciate that Beta is trying to bring better customer attention and service to the recreational marine industry—and their competitive pressure on big names like Yanmar and Volvo, but there is a reason that the boat manufacturers and charter boat operators generally use Yanmar engines. When you actually have to rely on their longevity and parts availability world wide, there is a choice. . . .

I spent 25 years with a Westerbeke marinized Perkins, and I can confirm that the marinization parts are definitely the weak leak, and outrageously expensive.


However, don't confuse Westerbeke with Beta. I know people who have put tens of thousands of miles on Beta engines and swear by them. The engineering of the Beta marinization parts is excellent and parts are no problem as long as you don't mind shipping them in. But as others have commented in most places you have to ship in Yanmar parts as well.


I really don't think you can go wrong with either one of these.

[StuartWeibel]

I replaced a Yanmar 1GM10 with a Beta 14. I did the installation on my own, a first engine installation. The experience was not without wrinkles, but the end result was satisfactory and having done it myself means that I have intimate knowledge of every aspect of the installation. This is good.

I am happy with the result: the engine is far smoother than the 1GM10, and I appreciate the extra power the engine has. Details of my experience are recorded in an extended blogpost at Re-powering s/v Ripple

Reading the responses to your post, the ones that struck me as most compelling are the few that actually reflect direct experience of both engines (as you requested in your query), and these posts lean strongly in favor of the Yanmar. While I am very happy with my new engine, I think a strong argument can be made for the Yanmar.

Best of luck