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

Snowgoose35 07-11-2019 10:42

Yanmar 3YM20 vs Beta 20
 
I need to repower and will get one of these - I can get both at so close to the same price that its not a decider and they have 1 hp difference in power and 4 ft lb more torque to the Yanmar but for 0.2L / hr greater fuel consumption - its a bit more fuel but again not enough to go one way or the other.

What really matters to me is a) reliability which reports show as very good for both and b) noise and vibration

I've watched video of both and its hard to see a difference but with mobile phone video sound is always poor so has anyone direct experience of both ?

I've heard people be very impressed by the smooth running of the Beta but can't find much about the Yanmar in this respect and my experience is only of the much older 3GM series which are very noisy and rattly - will the 3YM20 be better than the older ones?

Any feedback is gratefully received

skipmac 07-11-2019 11:28

Re: Yanmar 3YM20 vs Beta 20
 
I would take the Beta any time over the Yanmar. Beta is based on a tractor engine, no electronics to run it, easier to get parts, better customer service.

FlyingScot 07-11-2019 11:38

Re: Yanmar 3YM20 vs Beta 20
 
I'm a big fan of Yanmar. I would buy the Beta given a choice. Never heard any real negatives with Beta.

Snowgoose35 07-11-2019 11:45

Re: Yanmar 3YM20 vs Beta 20
 
Quote:

Originally Posted by skipmac (Post 3011191)
I would take the Beta any time over the Yanmar. Beta is based on a tractor engine, no electronics to run it, easier to get parts, better customer service.

What electronics are used to run the Yanmar 2YM20 ? It doesn't seem to have a black box like the bigger engines or have I missed something? That would be a major negative given how poor the latest Volvos have proven to be with all their electronic gubbins - I like stuff I can fix myself

Scubaseas 08-11-2019 10:26

Re: Yanmar 3YM20 vs Beta 20
 
3YM20 is still a "dumb" diesel without an ECU. Regular old HP injection pump and injectors. Both are good but I would go with the Beta.

ramblinrod 08-11-2019 10:35

Re: Yanmar 3YM20 vs Beta 20
 
Quote:

Originally Posted by Snowgoose35 (Post 3011154)
I need to repower and will get one of these - I can get both at so close to the same price that its not a decider and they have 1 hp difference in power and 4 ft lb more torque to the Yanmar but for 0.2L / hr greater fuel consumption - its a bit more fuel but again not enough to go one way or the other.

What really matters to me is a) reliability which reports show as very good for both and b) noise and vibration

I've watched video of both and its hard to see a difference but with mobile phone video sound is always poor so has anyone direct experience of both ?

I've heard people be very impressed by the smooth running of the Beta but can't find much about the Yanmar in this respect and my experience is only of the much older 3GM series which are very noisy and rattly - will the 3YM20 be better than the older ones?

Any feedback is gratefully received

Yanmar without any question. The design and technology is vastly superior to other brands. Many parts that are sand cast on others, are investment cast on Yanmars. You canít kill them even if you try (almost). They have a huge marine dealer network. They design and sell tractor engines too but their marine engines are marine engines. Betas are a 3rd party marinizer. Yes, one can get Kubota tractor parts from a tractor dealer, as can they get Yanmar tractor parts for a tractor dealer. But one cannot get Beta parts from a tractor dealer. Note, the starter, alternator, and some other parts you may get from a tractor dealer, are not marine grade, and should be called in your next survey for replacement.

That said, I love the way Yanmars start and run. Reasonably maintained, a Yanmar with 5000 hrs will start in 0C /30F weather without complaint, where other brands, require glow plugs.

Yanmar dealers are often near the water, where tractor dealers often ainít.

After many years of working on sailboat engines, I became a Yanmar dealer, because I admire them so. I only sell what I install, for an established customer (This post is not to solicit internet business, but rather advice based from a different perspective.)

We just purchased a used boat for our personal use that doesnít have a Yanmar, and if it wasnít perfect in every other way, including coming with a complete spare engine and transmission, I would have passed.

ramblinrod 08-11-2019 10:44

Re: Yanmar 3YM20 vs Beta 20
 
One more thing, of the 20 or so Youtubers we follow religiously, the two who have repowered with Beta, Project Atticus and White Spot Pirates have had what I consider, premature unexpected engine problems.

Not needing replacement parts, is much more important than saving a few bucks in needed replacement parts.

Supers0nic 08-11-2019 10:59

Re: Yanmar 3YM20 vs Beta 20
 
1 Attachment(s)
Yanmar in now producing the 3YM30AE. There are several upgrades from the previous model. I just had one installed in my 33í trimaran. It only has 4 hours on it but so far am very pleased

stormalong 08-11-2019 11:08

Re: Yanmar 3YM20 vs Beta 20
 
I am a happy Beta owner. I would suggest Beta because you will will be able to get Kubota parts anywhere. They are very reliable and well made. After about 4500 hours I have had very little maintenance needs.

Yanmar, which claims that their engines are designed for marine use has more limited parts availability and prices to match. I know that Yanmar also makes engines for small tractors but are the parts compatible and cross referenced? 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.

maine50 08-11-2019 11:24

Re: Yanmar 3YM20 vs Beta 20
 
Beta is set up to help self installers install their new engine. They can adjust the spread of the engine mounts usually to mean you don't have to change/fabricate new mounting beds. I think they are a better choice for the aftermarket customers. --Tim

ramblinrod 08-11-2019 11:46

Re: Yanmar 3YM20 vs Beta 20
 
Regarding replacement parts, Yanmar has the widest dealer network for marine engines in the world....by far.

In the first 20 years or 5000 hours of ownership, if you maintain your Yanmar properly, all you should need is oil, filters, belts, impellers, and possibly a thermostat, all in stock and very inexpensive from your friendly neighbourhood Yanmar dealer, or favourite online discount Yanmar retailer.

Iíve heard lots of round the campfire stories, but I have yet to meet a Yanmar I didnít like. If I had a choice of two boats to purchase, everything equal, but one with a Yanmar, the other a Beta, it wouldnít take one second of thought to choose the Yanmar.

The installed base is huge. There are used engines and pard everywhere. I can often get rarely required replacement parts for a 40+ year old Yanmar, within 24 hours, maybe 72 if it has to come up from the US.

3 years ago, was about to pull the trigger on a 3YM30 for my personal boat, when I found a 1985ish Yanmar 3GMF, that I knew /respected the shop that serviced it its whole life. Snapped it up after the shop test, where the engine started for the first time in weeks, in what felt like a fraction of a second Before I actually depressed the start button. I have absolutely the same affinity for the 3YM30. They come standard on many major production boats in the 28 to 35 ft range. Great engines.

Re Stories of ECU lightning issues. Anyone here ever had to replace one? I didnít think so. (The VP issue is a completely separate thing, grips design file followed by total incompetence). I feel for VP because employees with ďP Eng.Ē after their name shoulda done better.

If any diesel 12 Vdc system gets hit by a direct strike, such as to hurt the ECU, there will be far more issue than just the ECU, like rings welded to the cylinder walls.

By the way, if a boat mechanic tells you that you need a new ECU due to a lightning strike, tell them you will need the old part to send to Yanmar for analysis. 90% chance there is no issue, 9% chance they will replace the bad one as a spare for you, if you ask nicely. (They are truly that great of a company.)

a64pilot 08-11-2019 11:52

Yanmar 3YM20 vs Beta 20
 
I believe a Beta may be indirect injected, and if it is, and if the Yanmar is direct injected. I donít know if either is correct, but indirect injected Diesels are smoother and quieter than direct injected ones.
However direct injection is slightly more efficient, not so much to matter really, just as IDI is often quieter, but not hugely so.
https://www.hemmings.com/blog/articl...t-or-indirect/

If it doesnít have glow plugs, itís likely direct injected and if it does, it might be IDI.

ramblinrod 08-11-2019 13:08

Re: Yanmar 3YM20 vs Beta 20
 
Quote:

Originally Posted by a64pilot (Post 3011908)
I believe a Beta may be indirect injected, and if it is, and if the Yanmar is direct injected. I donít know if either is correct, but indirect injected Diesels are smoother and quieter than direct injected ones.
However direct injection is slightly more efficient, not so much to matter really, just as IDI is often quieter, but not hugely so.
https://www.hemmings.com/blog/articl...t-or-indirect/

If it doesnít have glow plugs, itís likely direct injected and if it does, it might be IDI.

The Yanmar 3YM series incorporates common rail EFI technology. Vastly superior in efficiency, reliability, and emissions reduction. You will not see black soot from the exhaust of one of these engines, coating a white transom, even if overloaded (poor prop selection).

Mike Banks 08-11-2019 13:51

Re: Yanmar 3YM20 vs Beta 20
 
A 3 cylinder diesel engine usually runs more smoothly than a two cylinder--so if vibration is a consideration I might source a 3.

I have a 3YM30 and it purrs.

westwon 08-11-2019 14:07

Re: Yanmar 3YM20 vs Beta 20
 
I have had a Beta 20 in my Newport 30 for 5 years now. The install was easy, the engine starts easily every time, and the maintenance could not be easier. I absolutely love the oil change pump that is directly fitted to the engine, the ease of inspecting the heat exchanger tubes, the water pump location, etc. I'm sure the Yanmar is great as well, but I'm very happy with the Beta. Oh, and the after sales support here in Canada (Gartside Marine in Sidney, BC) is outstanding.


Steve

donradcliffe 08-11-2019 14:16

Re: Yanmar 3YM20 vs Beta 20
 
As an unbiased customer, I would take the Beta hands down. In my experience, the Kubota engines are better built and more reliable. Parts are available from anyone at a reasonable price, compared to Yanmar's system of requiring you to buy from a dealer whose market (and markup) is protected.

While I was in Australia in the 90's, I heard of half a dozen catastrophic Yanmar failures in engines with less than 2000 hours, and Yanmar warranties offered NOTHING. I sail Tuesday nights on a Catalina 320 with a Yanmar 3GM. The owner has spent what a new engine would cost keeping that one running since 2000.

OTOH, I put a Beta 50 in my Beneteau as a repower, and my only problem in 2000 hours was the oil change pump, which Beta gave me a free replacement for. I talked to a friend who bought an Olson 40 with a 20 hp Kubota-based engine. The boat was on the beach after the famous Cabo storm, so he had it towed home and the engine torn down by his trucking company mechanics. They told him it was built like a Swiss watch, and had bearings not seen in other engines under 500 hp. I did the Baja Bash in a sistership. The Kubota overheated so badly it seized. We let it cool, but more water in it, and motored another 600 miles--no permanent damage. If it had been a Yanmar, at a minimum it would have need a new head gasket.

Not all Yanmars are bad--I've motored over 500 hours on several boats with the 4JHTE engines, and they are pretty reliable as long as you give them clean fuel with no air bubbles. They also have a good cooling system and are hard to overheat.

Snowgoose35 08-11-2019 14:32

Re: Yanmar 3YM20 vs Beta 20
 
Quote:

Originally Posted by Mike Banks (Post 3012006)
A 3 cylinder diesel engine usually runs more smoothly than a two cylinder--so if vibration is a consideration I might source a 3.

I have a 3YM30 and it purrs.

The 3YM20 is a 3 cylinder as is the Beta 20

Q Xopa 08-11-2019 14:33

Re: Yanmar 3YM20 vs Beta 20
 
Quote:

Originally Posted by ramblinrod (Post 3011902)
Regarding replacement parts, Yanmar has the widest dealer network for marine engines in the world....by far.

In the first 20 years or 5000 hours of ownership, if you maintain your Yanmar properly, all you should need is oil, filters, belts, impellers, and possibly a thermostat, all in stock and very inexpensive from your friendly neighbourhood Yanmar dealer, or favourite online discount Yanmar retailer.

Iíve heard lots of round the campfire stories, but I have yet to meet a Yanmar I didnít like. If I had a choice of two boats to purchase, everything equal, but one with a Yanmar, the other a Beta, it wouldnít take one second of thought to choose the Yanmar.

The installed base is huge. There are used engines and pard everywhere. I can often get rarely required replacement parts for a 40+ year old Yanmar, within 24 hours, maybe 72 if it has to come up from the US.

3 years ago, was about to pull the trigger on a 3YM30 for my personal boat, when I found a 1985ish Yanmar 3GMF, that I knew /respected the shop that serviced it its whole life. Snapped it up after the shop test, where the engine started for the first time in weeks, in what felt like a fraction of a second Before I actually depressed the start button. I have absolutely the same affinity for the 3YM30. They come standard on many major production boats in the 28 to 35 ft range. Great engines.

Re Stories of ECU lightning issues. Anyone here ever had to replace one? I didnít think so. (The VP issue is a completely separate thing, grips design file followed by total incompetence). I feel for VP because employees with ďP Eng.Ē after their name shoulda done better.

If any diesel 12 Vdc system gets hit by a direct strike, such as to hurt the ECU, there will be far more issue than just the ECU, like rings welded to the cylinder walls.

By the way, if a boat mechanic tells you that you need a new ECU due to a lightning strike, tell them you will need the old part to send to Yanmar for analysis. 90% chance there is no issue, 9% chance they will replace the bad one as a spare for you, if you ask nicely. (They are truly that great of a company.)

Being an agent is your opinion unbiased?

I am also a Yanmar owner, so I definitely am a biased happy Yanmar owner.

But I also know of many happy Beta owners.

Q Xopa 08-11-2019 14:42

Re: Yanmar 3YM20 vs Beta 20
 
Quote:

Originally Posted by donradcliffe (Post 3012027)
As an unbiased customer, I would take the Beta hands down. In my experience, the Kubota engines are better built and more reliable. Parts are available from anyone at a reasonable price, compared to Yanmar's system of requiring you to buy from a dealer whose market (and markup) is protected.

While I was in Australia in the 90's, I heard of half a dozen catastrophic Yanmar failures in engines with less than 2000 hours, and Yanmar warranties offered NOTHING. I sail Tuesday nights on a Catalina 320 with a Yanmar 3GM. The owner has spent what a new engine would cost keeping that one running since 2000.

OTOH, I put a Beta 50 in my Beneteau as a repower, and my only problem in 2000 hours was the oil change pump, which Beta gave me a free replacement for. I talked to a friend who bought an Olson 40 with a 20 hp Kubota-based engine. The boat was on the beach after the famous Cabo storm, so he had it towed home and the engine torn down by his trucking company mechanics. They told him it was built like a Swiss watch, and had bearings not seen in other engines under 500 hp. I did the Baja Bash in a sistership. The Kubota overheated so badly it seized. We let it cool, but more water in it, and motored another 600 miles--no permanent damage. If it had been a Yanmar, at a minimum it would have need a new head gasket.

Not all Yanmars are bad--I've motored over 500 hours on several boats with the 4JHTE engines, and they are pretty reliable as long as you give them clean fuel with no air bubbles. They also have a good cooling system and are hard to overheat.

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.

Compass790 08-11-2019 16:52

Re: Yanmar 3YM20 vs Beta 20
 
We have a yanmar engine but I would replace with Beta/kubota if buying new just because of Yanmars predatory parts pricing. However you should not need many parts for a long while if you maintain a new diesel properly.

ramblinrod 08-11-2019 17:06

Re: Yanmar 3YM20 vs Beta 20
 
Quote:

Originally Posted by Q Xopa (Post 3012041)
Being an agent is your opinion unbiased?

I am also a Yanmar owner, so I definitely am a biased happy Yanmar owner.

But I also know of many happy Beta owners.

Well, one can surmise what the will. All I can tell anyone is that I had serviced all brands of sailboat auxiliary diesels for years, and after developing a strong preference for Yanmar, I contacted them to become a dealer. The replacement parts business has not been nearly as lucrative as I had hopes, which is likely a testament to the reliability of the engines.

Re: Classification question by another poster. It is true that Kubota does not manufacture a marine engine. Yanmar does. Yanmar produces
Marine Recreational class engines to suit the needs of pleasure craft. They also produce Marine Commercial Engines to suit the needs of larger craft and work boats.

Having breadth and depth to the product range is not a bad thing. They can do this because they have earned a very large portion of the market, and have the sales volume to develop designs specific to narrower market segments.

Wotname 08-11-2019 17:37

Re: Yanmar 3YM20 vs Beta 20
 
Quote:

Originally Posted by Snowgoose35 (Post 3011154)
I need to repower and will get one of these - I can get both at so close to the same price that its not a decider and they have 1 hp difference in power and 4 ft lb more torque to the Yanmar but for 0.2L / hr greater fuel consumption - its a bit more fuel but again not enough to go one way or the other.

What really matters to me is a) reliability which reports show as very good for both and b) noise and vibration

I've watched video of both and its hard to see a difference but with mobile phone video sound is always poor so has anyone direct experience of both ?

I've heard people be very impressed by the smooth running of the Beta but can't find much about the Yanmar in this respect and my experience is only of the much older 3GM series which are very noisy and rattly - will the 3YM20 be better than the older ones?

Any feedback is gratefully received

Although the specs seem similar on the brochures, I would be asking what injection system is used.

I would only choose old style mechanical injection rather than common rail EFI (if there such a choice is available).

Old style injection is way way way more tolerant of fuel contamination issues. Super clean diesel and cruising can't be used in the same sentence.

If you are willing to take extreme efforts to ensure very very clean diesel is always available, then maybe it doesn't matter.

Quote:

Originally Posted by ramblinrod (Post 3011985)
The Yanmar 3YM series incorporates common rail EFI technology. Vastly superior in efficiency, reliability, and emissions reduction. You will not see black soot from the exhaust of one of these engines, coating a white transom, even if overloaded (poor prop selection).

While all you say is true, I would suggest that the reliability factor flies out the porthole as soon as one fails to keep the fuel supply ultra clean.

gulfcoastsailor 09-11-2019 03:43

Re: Yanmar 3YM20 vs Beta 20
 
ďAn engine mount has to be removed to change the raw water impellerď

Not true on mine.

Captain Bill 09-11-2019 05:22

Re: Yanmar 3YM20 vs Beta 20
 
Auxiliary parts such as starters and alternators are Not marine grade on Yanmars and are not even made by Yanmar. Mine are both made by Hitachi. They are not even painted by Yanmar. I had an exhaust elbow go bad and dump saltwater on the starter on one of my engines. It eventually failed. When I took it off and turned it over it still had the Hitachi label and part number on the bottom. I googled the part number and found that it is used on small lawn tractors from many different manufacturers including Kubota. So is the alternator. These are standard parts, not "marine grade". I have over 5000 hours on my Yanmars and the only thing I've had to do to the engines besides normal maintenance is replace the rear main seals in both engines. I have had to replace the heat exchanger on one engine which developed a leak and saltwater corroded an hole in the gasket face. While Yanmar may have an extensive service and parts network, I have had several instances where normal maintenance parts were not available anywhere in the US and had to be shipped from Japan with delays of up to 3 weeks, while sat in a boatyard running up daily fees for lack of a $20 seal, which according to Yanmar should be replaced every two years. Most of my problems with Yanmar have to do with the saildrives, which is not relevant to the OPs choice.



I have known a few people that have repowered with Betas and all of them are happy with their choice. When it comes time to repower my boat I will definitely be going with Beta.

bounty hunter 09-11-2019 22:48

Re: Yanmar 3YM20 vs Beta 20
 
Quote:

Originally Posted by Snowgoose35 (Post 3011154)
I need to repower and will get one of these - I can get both at so close to the same price that its not a decider and they have 1 hp difference in power and 4 ft lb more torque to the Yanmar but for 0.2L / hr greater fuel consumption - its a bit more fuel but again not enough to go one way or the other.

What really matters to me is a) reliability which reports show as very good for both and b) noise and vibration

I've watched video of both and its hard to see a difference but with mobile phone video sound is always poor so has anyone direct experience of both ?

I've heard people be very impressed by the smooth running of the Beta but can't find much about the Yanmar in this respect and my experience is only of the much older 3GM series which are very noisy and rattly - will the 3YM20 be better than the older ones?

Any feedback is gratefully received

does it matter to you that the Beta '20' only outputs 17-odd hp? whereas the yanmar is 21hp

the Beta '25' is a more direct comparison in terms of output

ramblinrod 10-11-2019 10:54

Re: Yanmar 3YM20 vs Beta 20
 
Quote:

Originally Posted by Wotname (Post 3012139)
Although the specs seem similar on the brochures, I would be asking what injection system is used.

I would only choose old style mechanical injection rather than common rail EFI (if there such a choice is available).

Old style injection is way way way more tolerant of fuel contamination issues. Super clean diesel and cruising can't be used in the same sentence.

If you are willing to take extreme efforts to ensure very very clean diesel is always available, then maybe it doesn't matter.



While all you say is true, I would suggest that the reliability factor flies out the porthole as soon as one fails to keep the fuel supply ultra clean.

Clean air and fuel is important to every ICE on the planet. I donít 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.

a64pilot 10-11-2019 13:14

Yanmar 3YM20 vs Beta 20
 
No, it has everything to do with fuel cleanliness and how long an injector will last.
Why a common rail needs perfectly clean fuel is due to fuel pressure, they run on average about 30,000 PSI. An average mechanical engine runs at about 800 PSI.
This very high fuel pressure will take any particle and actually cut the nozzle of an injector like a water jet cuts steel.
Couple that with the fact that a Common Railís injector tip hole size is so incredibly small means itís even more easily damaged.
It takes insanely high pressure for the Magic of Common Rail to work, like multiple injection events per cylinder firing etc. one reason they can run so smooth and idle so quiet is the a common rail can inject a tiny pre-shot of fuel early to get a fire going so that the main injection event burns smoothly and doesnít ďDieselĒ.

Jamming the pressure up so high means you can get all the fuel needed in a very short time, plus as each injector is individually managed and fired also enables things like adjustable timing to be simply a matter of programming, and lots of other magic like skipping cylinders and limp home modes etc.

Common Rails are a completely new type of Diesel and can do things like make Diesels real hot rods and make them as quiet as a gas motor. Just listen to any new Diesel pickup truck.

However it requires incredibly clean fuel, or you will be changing fuel injectors, and sit down when you price them, because they are mechanical marvels, that doesnít come cheap.

FlyingScot 10-11-2019 15:19

Re: Yanmar 3YM20 vs Beta 20
 
Quote:

Originally Posted by bounty hunter (Post 3012878)
does it matter to you that the Beta '20' only outputs 17-odd hp? whereas the yanmar is 21hp

the Beta '25' is a more direct comparison in terms of output

I don't see that in the specs.
Yanmar 21bhp vs Beta 20bhp. If you referring to maximum continuous power, Yanmar doesn't allow continuous full throttle operation either. This model seems to want 100 rpm less. My 3YM30 wants 200 rpm less.

FlyingScot 10-11-2019 15:21

Re: Yanmar 3YM20 vs Beta 20
 
Quote:

Originally Posted by a64pilot (Post 3013169)
No, it has everything to do with fuel cleanliness and how long an injector will last.
Why a common rail needs perfectly clean fuel is due to fuel pressure, they run on average about 30,000 PSI. An average mechanical engine runs at about 800 PSI.
This very high fuel pressure will take any particle and actually cut the nozzle of an injector like a water jet cuts steel.
Couple that with the fact that a Common Railís injector tip hole size is so incredibly small means itís even more easily damaged.
It takes insanely high pressure for the Magic of Common Rail to work, like multiple injection events per cylinder firing etc. one reason they can run so smooth and idle so quiet is the a common rail can inject a tiny pre-shot of fuel early to get a fire going so that the main injection event burns smoothly and doesnít ďDieselĒ.

Jamming the pressure up so high means you can get all the fuel needed in a very short time, plus as each injector is individually managed and fired also enables things like adjustable timing to be simply a matter of programming, and lots of other magic like skipping cylinders and limp home modes etc.

Common Rails are a completely new type of Diesel and can do things like make Diesels real hot rods and make them as quiet as a gas motor. Just listen to any new Diesel pickup truck.

However it requires incredibly clean fuel, or you will be changing fuel injectors, and sit down when you price them, because they are mechanical marvels, that doesnít come cheap.


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.

Cheechako 10-11-2019 15:42

Re: Yanmar 3YM20 vs Beta 20
 
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.

FlyingScot 10-11-2019 15:58

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.

Both are rated at 3600 rpm.

bounty hunter 10-11-2019 15:58

Re: Yanmar 3YM20 vs Beta 20
 
Quote:

Originally Posted by FlyingScot (Post 3013221)
I don't see that in the specs.
Yanmar 21bhp vs Beta 20bhp. If you referring to maximum continuous power, Yanmar doesn't allow continuous full throttle operation either. This model seems to want 100 rpm less. My 3YM30 wants 200 rpm less.

no i wasnt so much referring to the manufacturers maximum recommended continuous load - i was just pointing out something which i hadnt seen in earlier comments in the thread - and that was whilst both Yanmar and Beta's model designation suggests theyre both '20hp' - when making an 'apples-apples comparison', that the manufacturer supplied documentation tells a different story.

Yanmar docs show their motor outputting a maximum of 21 metric hp when measured under ISO8665 conditions;

https://www.yanmarmarine.com/theme/y...heet_3YM20.pdf

Beta's 'headline' number is 20hp - but if you take a closer look at the specs they publish here;

https://issuu.com/betamarine/docs/b2...14309/68213453

youll note a second - and lesser - output curve as measured at ISO8665 - which shows only about a maximu of 17mhp being produced - from this curve you can also calculate out that torque production is similarly slightly lower than the Yanmar engine

Cheechako 10-11-2019 16:02

Re: Yanmar 3YM20 vs Beta 20
 
Quote:

Originally Posted by FlyingScot (Post 3013248)
Both are rated at 3600 rpm.

OK, take a look at the HP curve and how do they compare on the way up to 3600 rpm. Does one develop more HP earlier? etc

FlyingScot 10-11-2019 16:46

Re: Yanmar 3YM20 vs Beta 20
 
Quote:

Originally Posted by bounty hunter (Post 3013250)
no i wasnt so much referring to the manufacturers maximum recommended continuous load - i was just pointing out something which i hadnt seen in earlier comments in the thread - and that was whilst both Yanmar and Beta's model designation suggests theyre both '20hp' - when making an 'apples-apples comparison', that the manufacturer supplied documentation tells a different story.

Yanmar docs show their motor outputting a maximum of 21 metric hp when measured under ISO8665 conditions;

https://www.yanmarmarine.com/theme/y...heet_3YM20.pdf

Beta's 'headline' number is 20hp - but if you take a closer look at the specs they publish here;

https://issuu.com/betamarine/docs/b2...14309/68213453

youll note a second - and lesser - output curve as measured at ISO8665 - which shows only about a maximu of 17mhp being produced - from this curve you can also calculate out that torque production is similarly slightly lower than the Yanmar engine

Good catch.

Quote:

Originally Posted by Cheechako (Post 3013254)
OK, take a look at the HP curve and how do they compare on the way up to 3600 rpm. Does one develop more HP earlier? etc

The Beta is a little smaller in displacement so I suspect the Yanmar makes more power through most of the rev range. Especially when accounting for what Bounty Hunter mentioned with the power ratings.

Uncle Bob 10-11-2019 17:34

Re: Yanmar 3YM20 vs Beta 20
 
Quote:

Originally Posted by ramblinrod (Post 3011985)
The Yanmar 3YM series incorporates common rail EFI technology. Vastly superior in efficiency, reliability, and emissions reduction. You will not see black soot from the exhaust of one of these engines, coating a white transom, even if overloaded (poor prop selection).



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.


Well, which is it, common rail or not. You cant both be right.

Wotname 10-11-2019 17:36

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.

FWIW, the Beta documentation shows it to be a traditional mechanical injection system while ramblinrod tells us the 3YM series are common rail EFI. I assume he is correct!

A common rail EFI would be a deal breaker for me!

Quote:

Originally Posted by ramblinrod (Post 3011985)
The Yanmar 3YM series incorporates common rail EFI technology. Vastly superior in efficiency, reliability, and emissions reduction. You will not see black soot from the exhaust of one of these engines, coating a white transom, even if overloaded (poor prop selection).


bounty hunter 10-11-2019 17:43

Re: Yanmar 3YM20 vs Beta 20
 
Quote:

Originally Posted by Uncle Bob (Post 3013299)
Well, which is it, common rail or not. You cant both be right.


RablinRod s statement that the 3ym is 'common-rail' hp injection is incorrect - a quick look at the Yanmar website confirms this

a64pilot 10-11-2019 17:43

Yanmar 3YM20 vs Beta 20
 
Quote:

Originally Posted by Cheechako (Post 3013254)
OK, take a look at the HP curve and how do they compare on the way up to 3600 rpm. Does one develop more HP earlier? etc



You canít break out Tq and HP separately. I know everyone tries to but they are interrelated.
Torque is a twisting moment, but no movement, RPM is of course speed. Torque times RPM x a constant 5252 is Horsepower. Decrease either torque or RPM and HP goes down, increase either or both and it goes up.

If you look at any dyno chart that the engine makes 5252 RPM or higher, youíll see that the HP and torque curves cross at exactly 5252 RPM, if they donít then the graph has been doctored, which happens more than you might think.

Then to further complicate things, it wouldnít matter if one did make more power down at a lower RPM, unless it was a HUGE difference.
The reason is the propellor will only use so much HP per RPM, so if you prop an engine correctly, that power that itís capable of making at low RPM wonít be used, cause you only pick a prop that matches engine output at one RPM, that being itís max RPM, so at any RPM less than max the engine is capable of producing more power than the prop will accept.

Uncle Bob 10-11-2019 17:48

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


Oh heaven forbid no, RamblinRod incorrect :whistling:, and him being a certified Yanmar dealer and all!! :biggrin:

skipmac 10-11-2019 19:04

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 donít 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.


Actually it makes a big difference. Common rail systems are much more complex and are quite different from an old style, mechanically driven injection system.



https://www.sae.org/publications/tec.../2010-01-2242/



To meet increasingly stringent diesel exhaust emissions requirements, original equipment manufacturers (OEMs) have introduced common rail fuel injection systems that develop pressures of up to 2000 bar (30,000 psi). In addition, fuel delivery schemes have become more complicated, often involving multiple injections per cycle. Containing higher pressures and allowing for precise metering of fuel requires very tight tolerances within the injector. These changes have made injectors more sensitive to fuel particulate contamination.


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