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-   -   Yanmar 3YM20 vs Beta 20 (https://www.cruisersforum.com/forums/f54/yanmar-3ym20-vs-beta-20-a-226210.html)

Dockhead 10-11-2019 19:12

Re: Yanmar 3YM20 vs Beta 20
 
Quote:

Originally Posted by Q Xopa (Post 3012047)
Im sure Rod or someone else can correct me, but I hear (unsubstantiated), that the Yamnar engines are 'recreational' rated, where as the Kubotas are 'argricultural/ industrial' rated. Which relates to their 'duty cycle'. Ie Industrial rated at higher loads for a greater proportion of their life than Recreational rated engines, that are not intended to be as abused, as much of their lives.


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.

Dockhead 10-11-2019 19:20

Re: Yanmar 3YM20 vs Beta 20
 
1 Attachment(s)
Quote:

Originally Posted by bounty hunter (Post 3013303)
RablinRod s statement that the 3ym is 'common-rail' hp injection is incorrect - a quick look at the Yanmar website confirms this


Indeed. He's confusing the 3YM with the 3JH40. 3YM has mechanical fuel injection using the classic Zexel injection pump:

Attachment 202954

Wotname 10-11-2019 19:44

Re: Yanmar 3YM20 vs Beta 20
 
Quote:

Originally Posted by bounty hunter (Post 3013303)
RablinRod s statement that the 3ym is 'common-rail' hp injection is incorrect - a quick look at the Yanmar website confirms this

Quote:

Originally Posted by Dockhead (Post 3013351)
Indeed. He's confusing the 3YM with the 3JH40. 3YM has mechanical fuel injection using the classic Zexel injection pump:

Attachment 202954

Two posts stating the 3YM series have old style mechanical injection (and a picture which has to be be worth a thousand words) - just need confirmation of this from a Yanmar dealer and the question will be settled for once and for all :wink:

Compass790 10-11-2019 20:02

Re: Yanmar 3YM20 vs Beta 20
 
Quote:

Originally Posted by Wotname (Post 3013361)
Two posts stating the 3YM series have old style mechanical injection (and a picture which has to be be worth a thousand words) - just need confirmation of this from a Yanmar dealer and the question will be settled for once and for all :wink:

How any Yanmar dealers would you need to canvass?:biggrin:

Dockhead 10-11-2019 20:11

Re: Yanmar 3YM20 vs Beta 20
 
Quote:

Originally Posted by stormalong (Post 3011862)
. . .I don't know which Yanmar it is but one of their "marine" diesels requires the removal of an engine mount to change the raw water impeller.


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 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 :banghead:).


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! :)

stormalong 10-11-2019 20:55

Re: Yanmar 3YM20 vs Beta 20
 
Quote:

Originally Posted by Dockhead (Post 3013376)
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 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 :banghead:).

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 10-11-2019 21:15

Re: Yanmar 3YM20 vs Beta 20
 
Quote:

Originally Posted by stormalong (Post 3013398)
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 10-11-2019 22:56

Re: Yanmar 3YM20 vs Beta 20
 
Quote:

Originally Posted by Dockhead (Post 3013344)
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 11-11-2019 01:31

Re: Yanmar 3YM20 vs Beta 20
 
Quote:

Originally Posted by Q Xopa (Post 3013459)
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 11-11-2019 02:00

Re: Yanmar 3YM20 vs Beta 20
 
Quote:

Originally Posted by Dockhead (Post 3013475)
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 11-11-2019 02:43

Re: Yanmar 3YM20 vs Beta 20
 
Quote:

Originally Posted by Q Xopa (Post 3013481)
. . .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 11-11-2019 08:57

Re: Yanmar 3YM20 vs Beta 20
 
Quote:

Originally Posted by Dockhead (Post 3013489)
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 15-11-2019 07:40

Re: Yanmar 3YM20 vs Beta 20
 
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 15-11-2019 07:42

Re: Yanmar 3YM20 vs Beta 20
 
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 15-11-2019 08:23

Re: Yanmar 3YM20 vs Beta 20
 
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 15-11-2019 08:55

Re: Yanmar 3YM20 vs Beta 20
 
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 15-11-2019 09:27

Re: Yanmar 3YM20 vs Beta 20
 
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 15-11-2019 09:33

Re: Yanmar 3YM20 vs Beta 20
 
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 15-11-2019 10:17

Re: Yanmar 3YM20 vs Beta 20
 
Quote:

Originally Posted by Pete the Cat (Post 3016287)
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 15-11-2019 10:37

Re: Yanmar 3YM20 vs Beta 20
 
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

stormalong 15-11-2019 11:28

Re: Yanmar 3YM20 vs Beta 20
 
Quote:

Originally Posted by nmccubbin (Post 3016228)
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

nmccubbin: It is interesting that you do not preheat. When I was at the Beta factory inspecting my new engine they told me it would be best to always preheat before a cold start. I do 10 seconds normally but 20 seconds on very cold days. The engine always starts in less than a second and I credit fast starts with long starter motor life. My old Perkins 4-108 also started easily but never that fast. I hear about so many sailors carrying spare starters and think it is totally unnecessary. The Perkins never needed a new starter in 17 years and the same with the Beta - now 16 years old (knock wood).

Quote:

Originally Posted by StuartWeibel (Post 3016377)
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

Stu, Your install writeup reminded me of my Beta 50 install. I am in the Seattle area now but replaced my Perkins 4-108 with a Beta 50 in England.

Working directly with the factory and the Beta Marine managing director made things go smoothly. The only external labor on my install was the craning out of the old and craning in of the new. One on the big advantages of Beta Marine is that they will do custom engine brackets. Maybe not cheap but they save so much labor that they are well worth it. I had to relocate the engine mount holes but that was easy compared to what many engine swappers go through with engine bed modifications. The tricky part was measuring properly which took me many tries with much concern about getting it right.

Part of my decision to go with Beta was the compatibility with the old Perkins. The fuel system and exhaust were a near perfect match. Now 16 years and about 4500 engine hours later I am still happy with the choice.

Visarend 15-11-2019 13:39

Re: Yanmar 3YM20 vs Beta 20
 
Quote:

Originally Posted by Cheechako (Post 3013233)
Compare RPM vs HP curves also. Yanmars are famous for rating at high rpm, thus making a lower HP engine appear to be higher HP. (Well... that's one way of saying it) I don't know about the Beta. I hated running my 3600 rpm Yanmars at 3400 rpm.


I had a look at torque curves, that I always find most interesting when dealing with non planing hulls. I see that Beta has a peak of 45 Nm @2600 rpm, while Yanmar has a flat maximum of 50 Nm from 2000 to 2400 rpm. According to those figures, it is probably interesting the possibility of choosing Yanmar and designing the drive train to obtain maximum (hull) speed at no more than 2400-2500 rpm, thus keeping a very good thrust at lower rpms. And I say that, notwithstanding the fact that I still keep in general a penchant towards Beta.

drcat 15-11-2019 15:40

Re: Yanmar 3YM20 vs Beta 20
 
What gets to me is the original question and this discussion. It's like should I buy a Rolls Royce or a Porsche? What about a Ford or GM or Toyota?
If a Beta is just a Kubota diesel with an added raw water pump and a water to water heat exchanger/ exhaust manifold, why spend the many added $s for the Beta when you can get a Kubota plus aftermaket raw water pump and a water to water heat exchanger/ exhaust manifold. Or go with a 12v variable speed magnetic drive raw water pump and avoid the issues we so often hear about of broken impellors and leaking pump seals.
There are also simple marine diesels out of China that are 20-25% of the cost of a Yanmar or Beta and probably millions of boats running them in Asia. Look at Alibaba.
If you got the bucks go spend it on Yanmar or Beta. If you are on a tighter budget consider alternatives.

Mauruuru 15-11-2019 15:43

Re: Yanmar 3YM20 vs Beta 20
 
I have a Yannar 3YM 30 that has been a great engine. I am going to replaceit when I convert to edrive but not because I ever had anyproblems with it just because I m convering to edrive. BTW my last boat was a 1970 Oday 30 with a single cylinder yanmar with lots of hours. Never let me down though there were some speeds where it would shake the bejesus out of the boat!

Old fella 15-11-2019 16:42

Re: Yanmar 3YM20 vs Beta 20
 
Quote:

Originally Posted by FlyingScot (Post 3013223)
Both the Yanmar 3YM20 and the Beta 20 are indirect injection.
https://www.betamarineengines.com/dow...C-SOM-0314.pdf
https://www.yanmarmarine.com/theme/y...heet_3YM20.pdf

I would not want common rail on a sailboat. The increased efficiency doesn't offset the complexity and increased difficulty of service.

I agree, it is common place for ford rangers and holden Colorados and others that there injectors **** themselves at only 70,000 k, and at a grand a peace, you can have that, plus in my boat I like things I can fix myself.

limte 15-11-2019 21:05

Re: Yanmar 3YM20 vs Beta 20
 
I'm a bit confused by the terminology used in this thread. Please correct me if I am wrong, but it is my understanding that direct vs. indirect fuel injection does not imply the same distinction as mechanical vs. electronic injection, nor the distinction between common rail and unit injectors. Also, I think that all available marine diesel engines with common rail injection are also direct injection with electronic control.


For example: my Beta 38 engine has indirect mechanical injection with unit injectors (not direct common rail with electronic injection).


In regard to the Beta engine, the support from Beta for owner installation was outstanding, and they were willing to make custom mounts for the engine, which saved me the great deal of work which would have been needed to remake the engine beds.



Regards,
Bob S

Wotname 16-11-2019 00:12

Re: Yanmar 3YM20 vs Beta 20
 
Quote:

Originally Posted by limte (Post 3016774)
I'm a bit confused by the terminology used in this thread. Please correct me if I am wrong, but it is my understanding that direct vs. indirect fuel injection does not imply the same distinction as mechanical vs. electronic injection, nor the distinction between common rail and unit injectors. Also, I think that all available marine diesel engines with common rail injection are also direct injection with electronic control.


For example: my Beta 38 engine has indirect mechanical injection with unit injectors (not direct common rail with electronic injection).


In regard to the Beta engine, the support from Beta for owner installation was outstanding, and they were willing to make custom mounts for the engine, which saved me the great deal of work which would have been needed to remake the engine beds.



Regards,
Bob S

Me too Bob :smile:

As I understand it, mechanical injection is simply what it says. A mechanically operated high pressure injection pump that injects diesel into the cylinder via the injector. A single shot of diesel is injected every compression stroke. It may go directly into the cylinder / head space or it may go into a pre combustion chamber located immediately at the end of the injector nozzle where it begins to ignite before the flame front moves further into cylinder / head space.

Common rail and EFI are (to my mind) synonymous terms and describe an injection system that operates at a much higher pressure and is electronically controlled. The fuel can be injected many times in the one compression stroke and in varying amounts at varying times.

A64pilot has described the process very well upthread.

I will leave it to others to explain direct and indirect injection differences:smile: ('cause I'm not totally sure)

Snowgoose35 16-11-2019 02:34

Re: Yanmar 3YM20 vs Beta 20
 
Well this has gone very off topic and as usual not really tried to answer the original question confined to those who had direct experience of both the Beta 20 and the 3YM20 - but I appreciate all the replies nonetheless

Just to be clear neither are common rail injection, neither have a black box (ECU whatever) and neither are hard to get to service parts - part of the reason I specifically asked about direct experience was to avoid comments that were irrelevant like that Yanmar on a 40 year old design had a silly place for the water pump (I've dealt with that one for 7 years) - the new Yanmar's have moved the water pump, moved the fuel filter and whilst the oil filter is still a little inaccessible if you need to get a full sized wrench on it, it is doable .

In the end I have ordered the Yanmar's - it was a close run thing as both are considered very reliable and the specs are close but the Yanmars make a bit more torque and are a direct fit in place of my existing ones. They also came out 15% cheaper than the Betas (despite getting a trade deal on the Betas) which frankly amazed me but that will pay for an awful lot of overpriced Yanmar oil filters if needs be :) The other useful advantage of the Yanmars is that they come as standard with 125a alternators and a digital control panel whilst the Betas have 40a and a very old fashioned looking panel

So once again thanks to all for the information both right and wrong (no offence but quite worryingly wrong from a claimed Yanmar dealer!!) but the decision is made now and the payment sent - just a 6 week wait for them to arrive and I can usher in an age of quiet vibration free engines which in my whole sailing career I have never known (having only had 3GMs in all my boats) .

Sputnik 16-11-2019 03:09

Re: Yanmar 3YM20 vs Beta 20
 
Good choice to go with Yanmar.
I have two friends who have fitted Beta 20......both have had massive problems with vibration issues after even though they have been fitted correctly and iaw the destructions.

Good luck, fair winds.

Neil

crankysailor 16-11-2019 05:45

Re: Yanmar 3YM20 vs Beta 20
 
I have a Yanmar btw and I just googled for a replacement panel and saw some list prices of $3000... someone is having a laugh and I guess eBay might yield options specially if one is willing to get a used one but the point is it seems to me that parts prices are rather high.. YMMV and if you have infinite bucks sure, you probably can't go wrong with the Yanmar.

longjonsilver 16-11-2019 05:57

Re: Yanmar 3YM20 vs Beta 20
 
Quote:

Originally Posted by drcat (Post 3016587)
If a Beta is just a Kubota diesel with an added raw water pump and a water to water heat exchanger/ exhaust manifold, why spend the many added $s for the Beta when you can get a Kubota plus aftermaket raw water pump and a water to water heat exchanger/ exhaust manifold.

i won't just tell you about it, i'll give you linx.

https://www.pumpvendor.com/sherwood_...ing_pumps.html

https://www.brazetek.com/shell-tube-heat-exchangers

jon

Dockhead 16-11-2019 15:29

Re: Yanmar 3YM20 vs Beta 20
 
Quote:

Originally Posted by Wotname (Post 3016824)
. . . I will leave it to others to explain direct and indirect injection differences:smile: ('cause I'm not totally sure)


It's simple -- indirect injection uses a pre-chamber, and direct injection does not.



My Yanmar 3TN74 driving my generator is indirect. My Yanmar 4JH3 HTE main engine is direct. Both use Zyxel mechanical fuel injection.


Direct injection engines are more thermodynamically efficient (less thermal losses), but noisier, and easier to start. They are more demanding of injection pumps and injectors.



The thing I like best about direct injected diesels is they are much easier to start. My 4JH3 HTE starts if you just look crossways at the starting key -- does not require even a full revolution even in subzero weather. I have never used the air heater and I'm not sure it even works.


Previous indirect injected diesels I've owned have been more challenging to start, and required the use of glow plugs.



See:


https://learnmech.com/what-is-direct...ect-injection/

a64pilot 16-11-2019 15:53

Yanmar 3YM20 vs Beta 20
 
IDI motors gained widespread acceptance in I guess the 80’s for automobiles, they can be lower compression and therefore lighter weight motors and I believe they can be less harsh that a direct injected motor, and also they are easier to make pass emissions, or used to be anyway.
They can also turn much higher RPM, my old VW Golf would turn 5,000 RPM I think.

Common rail really unfortunately isn’t any more efficient, you would think it would be, and maybe if it’s tuned to ignore emissions it could be I don’t know.
Passing emissions on a Diesel is tough, real tough, and expensive, that’s why so many automakers (it wasn’t just VW, they ALL cheat) ,if you cheat you can save a lot of money.

Anyway very precise control of fuel is required to pass strict emissions, and that means common rail, it or maybe a similar technology is going to happen if emissions come anything close to US automotive standards, only way out will be buy an old boat.
https://carbiketech.com/indirect-injection/

A major problem with making a Diesel pass emissions isn’t the type of ignition, but the type of fuel.
I predict we will soon see hybrid gas/Diesel engines, that is gasoline engines that are compression ignited, this will of course require high pressure direct injection (common rail if you will)

You see one of the major differences between gas fuel injection and Diesel is that a gas motor’s injector can spray continuously on the back side of the intake valve, then when the valve opens the fuel air mixture is drawn into the motor, and it doesn’t ignite until a spark plug fires because the compression is so low, higher compression gives you more power but requires higher Octane fuel or the whole fuel charge instantly burns, called detonation, and detonation is not valve rattle, detonation destroys an engine pretty quickly, usually Knocks a hole in the piston. The Holy Grail for a gas motor would be high compression with low octane fuel, and I think that’s coming.

The heat of compression is so high on a Diesel that combustion begins the instant fuel becomes present when the engine is up to temp and running under a load, for this reason only a tiny fraction of a second is available to get all the fuel in and flow stopped, this more than anything else limits the RPM of a Diesel, Jack up the fuel pressure to say 50,000 PSI and that time shortens a whole lot, and now you can have a hot rod Diesel with common rail.

So, take a gas motor, jack up the compression to gain efficiency etc. and direct inject the fuel so that the moment fuel becomes present the burn begins.
You have a hybrid gas/Diesel cause I’d suspect it will still have spark plugs for cold weather operation and starting etc.

Compass790 16-11-2019 17:16

Re: Yanmar 3YM20 vs Beta 20
 
Quote:

Originally Posted by Snowgoose35 (Post 3016842)
Well this has gone very off topic and as usual not really tried to answer the original question confined to those who had direct experience of both the Beta 20 and the 3YM20 - but I appreciate all the replies nonetheless

Just to be clear neither are common rail injection, neither have a black box (ECU whatever) and neither are hard to get to service parts - part of the reason I specifically asked about direct experience was to avoid comments that were irrelevant like that Yanmar on a 40 year old design had a silly place for the water pump (I've dealt with that one for 7 years) - the new Yanmar's have moved the water pump, moved the fuel filter and whilst the oil filter is still a little inaccessible if you need to get a full sized wrench on it, it is doable .

In the end I have ordered the Yanmar's - it was a close run thing as both are considered very reliable and the specs are close but the Yanmars make a bit more torque and are a direct fit in place of my existing ones. They also came out 15% cheaper than the Betas (despite getting a trade deal on the Betas) which frankly amazed me but that will pay for an awful lot of overpriced Yanmar oil filters if needs be :) The other useful advantage of the Yanmars is that they come as standard with 125a alternators and a digital control panel whilst the Betas have 40a and a very old fashioned looking panel

So once again thanks to all for the information both right and wrong (no offence but quite worryingly wrong from a claimed Yanmar dealer!!) but the decision is made now and the payment sent - just a 6 week wait for them to arrive and I can usher in an age of quiet vibration free engines which in my whole sailing career I have never known (having only had 3GMs in all my boats) .

FYI you have no need to use the genuine yanmar oil filters AFTER the warranty has expired, you can just find a baldwin or other crossover filter.
Good bonus getting 125A alternators. Hope you update the post to tell us your impressions after you install the new engines tho it will make me grind my teeth with jealousy if you say it's quiet & vibration free as we have a Yanmar single:smile:

a64pilot 16-11-2019 19:07

Re: Yanmar 3YM20 vs Beta 20
 
You don’t have to use “genuine” Yanmar filters or oil from day 1, but you may have to prove you followed service intervals and used an oil of the correct grade.

Wotname 16-11-2019 21:42

Re: Yanmar 3YM20 vs Beta 20
 
Quote:

Originally Posted by Dockhead (Post 3017241)
It's simple -- indirect injection uses a pre-chamber, and direct injection does not.


.........

The thing I like best about direct injected diesels is they are much easier to start. My 4JH3 HTE starts if you just look crossways at the starting key -- does not require even a full revolution even in subzero weather. I have never used the air heater and I'm not sure it even works.


Previous indirect injected diesels I've owned have been more challenging to start, and required the use of glow plugs.



See:


https://learnmech.com/what-is-direct...ect-injection/

Thanks for the explanation.

I don't think the claim that indirect injection makes the engine hard to start is universally true. I don't dispute that it may be true in some instances or for some engines..

E.G. Both of the 2GM20 engines I had started in the same manner as your 4JH3 HTE. Look sideways at the key and think start! They have pre com chambers and no glow plugs.

Perhaps it makes a difference if engine has lost some compression and/or has a compromised electrical supply to the starter motor. I can't speak to those conditions 'cause I haven't experienced them on an IDI engine!

ramblinrod 20-11-2019 10:16

Re: Yanmar 3YM20 vs Beta 20
 
Quote:

Originally Posted by ramblinrod (Post 3013099)
Clean air and fuel is important to every ICE on the planet. I don’t believe there is any difference in sensitivity between common rail and cam driven pumps, an injector orifice is an injector orifice. How the injector is driven has no connection to the fuel supply IMHO.

Thanks to those who questioned.

I have been very busy winterizing boats as a result of recent cold snap, and have not been able to post.

I stand corrected on two counts, a result of posting from memory, while rushed to perform boat winterizing services, without any fact checking on my part.

First, the Yanmar 3YM series does not incorporate common rail fuel injection technology, as I previously stated.

There has been a lot of discussion surrounding this technology, and I erroneously associated it with the Yanmar 3YM line. I knew better, it was simply "a momentary lapse".

Under this false presumption, as my experience with the 3YM line is that they are very, very reliable, I responded that the common rail technology is no more susceptible to fuel contamination than mechanical fuel injection.

This should have simply read, the 3YM is not prone to fuel injection problems or any more sensitive to fuel contamination than any other small rec boat diesel.

That said, it is true that common rail technology engines (which the 3YM is not) may be more sensitive to fuel contamination than mechanical fuel injection engines, from the perspective that the fuel pressure is much higher, and orifices may be smaller.

But the truth is, as I stated, that all diesel engines require clean fuel and air to perform reliably; meaning that regardless of fuel injection technology it is or utmost importance to feed clean air and fuel to every diesel engine. A slug of dirt or water can stop a diesel of any technology, dead in it's wake, and I have performed many repairs on poorly maintained, non common rail engines, to prove it.

The advantages of common rail technology are numerous, and like every design or purchase decision, there are pros and cons.

To me, for the larger Yanmar rec boat engines, the benefits of improved performance, fuel economy, ability to modify the fuel injection parameters if needed, and carbon emissions reduction, warrants consideration despite the possible higher sensitivity to fuel contamination (which should not be present in the first place). This could prove very important to the average boater as environmental regulations become more stringent, as we all know they will.

The same holds true for turbos. Yes they add moving parts which, and as such are an additional potential failure point, but improved performance, better fuel economy, and emission reduction is the benefit.

Notwithstanding, the 3YM series does not incorporate common rail technology, so this is simply not a consideration when evaluating a repower opportunity with one.

Based on my experience with these engines, from the vessel to the corporate level, given a choice between a Beta and Yanmar repower, even with the Yanmar was 20% more expensive (which they usually are not) I would choose the Yanmar every time BEFORE I became a Yanmar dealer, solely based on my experience servicing ALL diesel engines used in marine applications for rec boats from 20 to 50 ft.

Sorry for any confusion my previous post may have caused.


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