New Yanmar outboard diesel- perfect for TT35

I just noticed Yanmar's announcement of a new 50 hp diesel outboard in cooperation with a German manufacturer. It is based on common rail injection and has dual crankshafts to reduce vibration from the 2 cyl engine. See:

YANMAR LAUNCHES THE DTORQUE 111 TURBO DIESEL OUTBOARD - Yanmar Marine

Certainly they will be expensive but a pair of these would be ideal for the TT35 if the buyer were going to put several hundred hours each year on them so the lower fuel consumption might pay for them. Not to mention at least double the engine life of a gasser.

David

Very interesting.

Suspect the oil change interval will be 100 hours, same as the gassers.

"Certainly they will be expensive but a pair of these would be ideal for the TT35 if the buyer were going to put several hundred hours each year on them so the lower fuel consumption might pay for them. Not to mention at least double the engine life of a gasser."

I'm don't think an extra $10,000 in engine costs would be paid back by a lower fuel burn.

Modern gassers can get 14HP from a gallon of gas , modern diesels still get about 20Hp if properly loaded.

Diesel costs more than gasoline , but at lest doesn't die in the tank from Ethanol .

Many small trawler will burn 2-4GPH of diesel, at 3-5GPH on gas a few hundred hours a year might not make back that $10,000 very soon .

4000 Hours is current gas engine life , perhaps double that for diesel inboards.
10,000 claimed by mfg , but it will be a while to see if its just puff.

Not sure if diesel outboards will be problem free , the diesel pod drives do not seem to last long.

Thanks for posting. I hope its successful. If it is, others will follow and it will all be good for us.

There used to be dozens of these in various HP ratings running around Block Island and the east end in pump out and service boats - maybe 15 years back.
They were in service for many years - wonder what happened to them?

Instead of two DTorques, how about one OXE?

OXE - DIESEL OUTBOARD

More on the DTorque: https://www.neander-dtorque.com/dtorque/

Diesel power would go a long way to improve my opinion of the design as a trawler use type. The anesthetics well that is another issue that hinges on personal preferences. There are a lot of ugly aluminum work and fishing boats in the PNW the bulk of them proving their worth by performance practicality and toughness so to some they are beautiful in a way. Time will tell if the TT35 can earn its wings and I think reliable diesel power would be a leg up. Many of the proven and time tested PNW aluminum boats would be in direct completion with this design and if aesthetics is not a big issue I would go diesel and aluminium.

FF said:

Diesel costs more than gasoline , but at lest doesn't die in the tank from Ethanol .

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???

Marine -- i.e., at the fuel docks -- gasoline around here is more expensive than diesel...

-Chris

ranger42c said:

???

Marine -- i.e., at the fuel docks -- gasoline around here is more expensive than diesel...

-Chris

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Every place we stop for diesel fuel on our way south has gasoline priced significantly higher than diesel.

Guess it's regional - not the case on the mid-Gulf.

First, I'm not convinced a new product is going to be more dependable than mature products used for decades nor am I convinced there would ever be a payback.

However, a more basic issue. Even the attempt seems to be an effort to fix a problem that doesn't exist. Only in the trawler world does there seem to be such an aversion to gas. There are economical and dependable gas outboards that do the job just fine.

We have been using the Yanmar diesel outboards (D27 and D36) for many years and still do, (although out of production some years back) the last units we purchased around 2010 out of Australia cost AU $ 24'790,(36 hp)

These units take a beating from our third world boat crews but keep on running, although down on horse power the torgue is amazing to say the least, yes oil changes are recommended @ 100 hours but spin on filters and small lube capacity it's not an issue, I guess the biggest draw back we find is their weight @ 100 kg's - 120 kg's (Dry).

Cheers Steve

BandB said:

First, I'm not convinced a new product is going to be more dependable than mature products used for decades nor am I convinced there would ever be a payback.

However, a more basic issue. Even the attempt seems to be an effort to fix a problem that doesn't exist. Only in the trawler world does there seem to be such an aversion to gas. There are economical and dependable gas outboards that do the job just fine.

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diesel OB is not new and is very well tested particularly in commercial use. The reason it was pulled from US market had nothing to do with mechanical function it was an environment thing. OB & diesel does have its good side and when applied and fit to good use makes sense on some boats. I think with advanced engineering we will see the return of the aborted OB diesel market.

TO NOTE: Yanmar claims the new outboards fall well within the latest EU RCD 2 limits.

What I still don't understand is why is there a need for diesel OB's for recreational use?

BandB said:

What I still don't understand is why is there a need for diesel OB's for recreational use?

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With diesel OB tender, single fuel on board. Important for some.

Insequent said:

With diesel OB tender, single fuel on board. Important for some.

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But then that's an application where the weight of the diesel is most negative.

BandB said:

But then that's an application where the weight of the diesel is most negative.

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Not necessarily. For larger tenders and not wanting high speed its fine.

I looked at the DTorque website that someone posted a link to. It has a displacement of 0.8 liters and is turbocharged. Making 50 hp that means it produces 63 hp per liter which puts it in the range of most current turbocharged, common rail engines.

I don't think you can make any comparisons with the old Yanmar O/Bs. Those used the GM block I believe which was 1 liter and produced 27 hp and did not have a turbocharger. The old GM engine was very robust and had a long life.

This new engine uses an all new crank system which has no long term history. Time will tell how it holds up. I wouldn't buy one until I see how it does after a few years.

The target market is for European commercial workboats that put a lot of hours each year on them and can benefit from the lower fuel consumption and the hopefully longer life.

It will take a unique customer that can benefit from the new diesel in a TT35: One that cruises fast so the fuel consumption will be important and puts several hundred hours each year on his engines.

David

djmarchand said:

I just noticed Yanmar's announcement of a new 50 hp diesel outboard in cooperation with a German manufacturer. It is based on common rail injection and has dual crankshafts to reduce vibration from the 2 cyl engine. See:

YANMAR LAUNCHES THE DTORQUE 111 TURBO DIESEL OUTBOARD - Yanmar Marine

Certainly they will be expensive but a pair of these would be ideal for the TT35 if the buyer were going to put several hundred hours each year on them so the lower fuel consumption might pay for them. Not to mention at least double the engine life of a gasser.

David

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Some time past, I started a thread on the new Neander tech diesel outboard with the double crank, so interesting that Yanmar is using this now!
I like it but I will also never own it.
http://www.trawlerforum.com/forums/s6/neander-tech-diesel-outboards-30968.html

That twin counter rotating crank on a two cylinder is a really neat configuration. Kudos to the guys that came up with it, although I suspect it may be an old concept.

Two cylinder four strokes have always been infernal beasts. You could choose to have the pistons moving together to get an even 360deg firing pattern, but that would leave to a horrible mass balance no better than a single cylinder. If you put big weights on the crank you can balance some of this, but with a single crank, any weights will also cause lateral forces which is just another vibe. Yuk.

You could have the pistons moving 180deg out like a two stroke outboard, that leads to better mass balance but in a four stroke now your firing pulses are way off balance (think Harley).

This arrangement fixes things. You have the pistons moving together so you get the even firing. The mass of the two pistons going up and down can nearly all be counteracted by weights on the two cranks. Since the cranks are counter rotating, the forces from these weights create no lateral forces, only up and down which is in the right direction to counteract forces from the pistons moving up and down.

Neat stuff.

Engine still is going to have a vibe problem at low rpm due to the high compression of a diesel and the low cylinder count. The fix is to set the idle rpm up, but that combined with relative low peak rpm (compared to a 6000rpm gasser) means that there simply is not a lot of rpm "room" between idle and cruise and full rpm.

We see this problem on go fast diesel boats with big engines; idle at 600, cruise at 1800, max at 2300. Nice to go fast at 1800, but that also means you are going pretty fast at 600!! Not fun in no wake zones and around the dock.

How social this thing is remains a question to me.

And I also think it is a niche product, when you critically analyze the cost/weight/performance/social skills/longevity factors it will lose out to the gasser outboard in most apps.

Still neat stuff...

Just a matter of money and weight unless range is critical.

Diesel OB is not appealing to me.

David,
I have a friend that had an engine in his sailboat w the two counter rotating crankshafts and he said it was amazingly smooth. Could be the future for small diesel engines. On an OB there is (or could be) a built in advantage in that one can pick what crank to take the power from. This can be a big bonus feature as the other crank and all the weight there can be placed for best CG. Honda ofset a crankshaft on at least one engine to gain a CG advantage. The offset moved the powerhead fwd for better balance. However the weight of the ofset crank may be too heavy for good balance on this diesel ... or even a problem.

I remember that prior thread on the Neander. Then I thought it was an obscure company with a tiny niche product that probably wouldn't sell in the real market. Now that Yanmar is selling them, it puts them in the mainstream.

I do expect them to be heavy- two cranks has got to be heavier than one, plus all of that torque takes beef to contain it. An equivalent gasser outboard has about a liter of displacement and weighs 250 lbs. I saw one blurb that said the Neander weighs 385 lbs. That shouldn't bother the TT35 and the work boat market that it targets.

David

I would not mind owning one, not objecting to the technology, I think it is a cool idea, but I will never be in the market for an outboard and likely costs a lot too.

MurrayM said:

Instead of two DTorques, how about one OXE?

OXE - DIESEL OUTBOARD

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Did you see that the OXE outboard uses belt drives? While it may be quieter and might slip to save a prop, I think you'll spend a lot on belts through the life of the outboard.

Guided sport fishing and other commercial operations might stand to gain the most as these engines “should” have greater longevity and lower fuel costs. They go through outboards quite quickly.

stubones99 said:

Did you see that the OXE outboard uses belt drives? While it may be quieter and might slip to save a prop, I think you'll spend a lot on belts through the life of the outboard.

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I can't find any links to a maintenance schedule or service manual for these engines, so don't know how often the belts should be replaced...but it appears to be soft on belts (can supposedly perform a smooth crash stop) as demonstrated here:

These new gas outboards are so reliable and efficient (if propped properly and at lower speeds). I'd much rather have 2 Yamahas on the back of my TT 35......if I was buying one!

Lets come back in five years and I think the issue of diesel OB will be settled one way or the other. The market performance and maintenance and dependability issues will be sorted out.