2 stroke inboard new tech?

DoubleEnder

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I don’t normally post in this forum, I have a sailing boat. But I saw this in Düsseldorf and I thought it looked interesting. A lightweight 2 stroke boxer engine, petrol driven. The one on the stand was hooked up to a saildrive but they said they are working on a gearbox/shaft arrangement.
https://www.arens-motors.com/arens-rvi-boxer-engine.html

FWIW.
The available engine solutions for small and midsize sailing boats are all a bit 20th century, if you’re lucky. I have a Beta diesel and while I have no complaints it would be nice if something more modern were available. Maybe hybrid electric is going to be the way .... but I liked this dinky little thing.

Apologies if I have strayed on to forbidden ground. I fear I’d just get told to love my diesel in the other place, and I think it’s fun to see new ideas.
 

Poignard

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A lovely little thing but petrol? No thanks!

Although having said that, I remember sailing Norfolk Broads cruisers with inboard Stuart-Turner petrol engines on which we cooked with open flames and smoked cigarettes without giving a moment's thought to the death-trap lurking in the cockpit locker! :D
 

Ferris

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Nothing wrong with petrol once the installation is good, I presume you've had a petrol car that didn't blow up.

With small craft (e.g. a small Freeman, dayboats, launches etc.) I can't understand why you would want a Diesel when a small petrol would be smoother and quieter. I was once a guest on a Freeman 23 running a ford sea panther petrol engine and it was a revelation in that type of boat and economy simply doesn't come into it at that size of engine.

Another more well established option for two-stroke petrols: http://www.dolphinengines.co.uk/
 

Poignard

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..... I presume you've had a petrol car that didn't blow up.
I must confess that I never have had a petrol car blow up.

I have had petrol leaks but they posed little risk since the petrol and vapor dropped onto the ground below (there being nothing in which it could accumulate) and quickly evaporated.
 

Ferris

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I must confess that I never have had a petrol car blow up.

I have had petrol leaks but they posed little risk since the petrol and vapor dropped onto the ground below (there being nothing in which it could accumulate) and quickly evaporated.

Point taken but are we are inundated with petrol boats going up like roman candles? Surely it ranks quite lowly in occurrence even if the severity of an incident is high. I suggest that there are multiple greater risks in boating. Mostly these engines would find there way to inland craft so the BSS sets a minimum standard for installation.

In my mind, assuming meagre fuel consumption of this type of engine and a lack of riverside petrol supply, I would be fuelling from 25l outboard fuel tanks for ease of refueling and risk reduction by only needing to decant once. This would also allow easy ID of leaks. Not sure if BSS allows this but that does not apply in my jurisdiction.

Point still stands, in many small boats a light, quiet, smooth petrol is an infinitely more pleasant than a comparable diesel powerplant.
 

gordmac

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Nice little engine, 2.5 times more powerful than the Dolphin and half the weight. Modern 2 stroke outboards are as economical as 4 stroke. Well worth thinking about for a smallish displacement vessel I would think.
 

No Regrets

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With small craft (e.g. a small Freeman, dayboats, launches etc.) I can't understand why you would want a Diesel when a small petrol would be smoother and quieter. I was once a guest on a Freeman 23 running a ford sea panther petrol engine and it was a revelation in that type of boat and economy simply doesn't come into it at that size of engine.

The Sea Panther will probably still be going in it's original untouched format. A Two stroke would not.

Thats why. And you wrongly assume the huge benefits the Diesel has in running costs would not matter to anybody.

One of the most foolish posts I have seen even on this forum in quite a while :nonchalance:
 

No Regrets

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Nice little engine, 2.5 times more powerful than the Dolphin and half the weight. Modern 2 stroke outboards are as economical as 4 stroke. Well worth thinking about for a smallish displacement vessel I would think.

Modern Two-stroke outboards are not as economical as Four strokes. Not on fuel or oil. :disgust:
 

Ferris

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The Sea Panther will probably still be going in it's original untouched format.
I agree, the one in the freeman I was on seemed in rude health

A Two stroke would not.
tell that to Yamaha. Why do commercial fishermen still but them, albeit where gas prices are reasonable. Personally ran a fleet of Yamaha two strokes in my local club that ran into thousands of hours.

Thats why. And you wrongly assume the huge benefits the Diesel has in running costs would not matter to anybody.
Running cost matter of course, but I doubt that the difference in fuel costs between a small diesel and a small petrol is significant compared to overall berthing costs, we’re not talking about a benetti here, small motorboats and launches where smooth and quiet operation is arguably worth the small additional expense.

One of the most foolish posts I have seen even on this forum in quite a while :nonchalance:
if you think so, yours is one of the most arrogant.
 

rotrax

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Having looked at the Web site, the engines appear to be 4-strokes. They merely claim that they are as light as 2-strokes.

I don't think so-I cant see any valve gear and the lubrication system is stated to be multi point injection. Not at all common on four stroke engines which also normally require a sump or a dry sump oil tank, neither mentioned or visible.

The engine may very well be a modern development of the Konig flat four two stroke engines used in successful hydroplane racing boats-and racing sidecar outfits. The light weight and high power of the Konig's were winners in both boats and motorbikes.

I would hope the reliability would be better today, they were often non finishers!

I have just looked at the link again, it states it has the advantages of a two stroke design with the fuel economy of a four stroke, so its a two stroke. The toothed belt disc valve drive is very Konig-esque. So I am pretty sure its a modern Konig.
 
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