How longs a piece of string question : Volvo Penta TAMD41 inu dp 90 fuel consumption

I puzzle about lots of the questions asked here. These days you don't even have to RTFM. Just type into whatever AI you use. I typed into Gemini "tamd41 fuel consumption graph url". It more than answered the question and gave a nice graph also. It will also tell you which page to look at. I expect ChatGPT will get you there also. Knowledge is free these days!
 
ss2016 said:
I puzzle about lots of the questions asked here. These days you don't even have to RTFM. Just type into whatever AI you use. I typed into Gemini "tamd41 fuel consumption graph url". It more than answered the question and gave a nice graph also. It will also tell you which page to look at. I expect ChatGPT will get you there also. Knowledge is free these days!
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1. RTFM is a zero answer as it has no info at all ... Volvo say they wont give figures as they don't know what boat its fitted to.

2. I don't knowingly use AI as each time I have - its provided bulls*** answers based on info its taken from online ...

3. I did search on line and I have found figures ranging from 30 to 130ltrs per hour ...

Does that answer why I ask here ? Maybe someone has a similar boat ... that would be the figures I would trust more ...

You may trust AI - but I know I am not only one who doesn't.
 
Refueler said:
Boat 30ft planing hull Flybridge ...

Motorbåt HSÖ 30 1981 säljes på Gotland | Blocket

Ball park figure ?

Would 30lts / hr be about cruising speed or ??
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Hi, good afternoon!

For 21 years I owned a German Cabin Cruiser, Cytra 31 Courier, with 2x VP AQAD 41 DP.

Very fast, 33 kn, very economic!

Have a look to my statistic, Nautic (3).

I think with a single engine the consumption of the shown boat will be between 30-40 l/h at a cruising speed around 18-22 knots.

Going slow on rivers or canals it will be less than 10 l/h I/h.

I was very pleased with the engines, consumption, noise, technic nearly without problems.

1 x fuse for the lift of the z-drive

1x Injector

1x cap of the fresh water cooling pot

1x generator belt

But every two years trouble with the Z-drives! Clutch, lift, water in oil, cardan shafts.

The biggest problem was the extreme exhaust smoke after starting the engines, series A.

Cordially! Stefan
 
Nessy said:
Hi, good afternoon!

For 21 years I owned a German Cabin Cruiser, Cytra 31 Courier, with 2x VP AQAD 41 DP.

Very fast, 33 kn, very economic!

Have a look to my statistic, Nautic (3).

I think with a single engine the consumption of the shown boat will be between 30-40 l/h at a cruising speed around 18-22 knots.

Going slow on rivers or canals it will be less than 10 l/h I/h.

I was very pleased with the engines, consumption, noise, technic nearly without problems.

1 x fuse for the lift of the z-drive

1x Injector

1x cap of the fresh water cooling pot

1x generator belt

But every two years trouble with the Z-drives! Clutch, lift, water in oil, cardan shafts.

The biggest problem was the extreme exhaust smoke after starting the engines, series A.

Cordially! Stefan
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Thank you ... for not quoting AI !! (y)
 
ss2016 said:
I puzzle about lots of the questions asked here. These days you don't even have to RTFM. Just type into whatever AI you use. I typed into Gemini "tamd41 fuel consumption graph url". It more than answered the question and gave a nice graph also. It will also tell you which page to look at. I expect ChatGPT will get you there also. Knowledge is free these days!
Click to expand...
So let's all leave these forums and ask AI (y)

Oh, hang on, where do you think AI gets it's info ? From stuff others have posted online ? It isn't exactly AI, more like a fancy search engine.
 
PaulRainbow said:
So let's all leave these forums and ask AI (y)

Oh, hang on, where do you think AI gets it's info ? From stuff others have posted online ? It isn't exactly AI, more like a fancy search engine.
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AI .... just a session searching Youtube and you watch some of the so-called 'news' .... but as you watch them - you realise how much is utter tripe !

Problem is AI does not seem to distinguish between 'false online info' and factual. It includes the lot !!
 
colhel said:
The advert says tmd41 and you're thread title says tamd41. We have the tamd41a which is a 6cyl 200hp with turbo. I googled tmd41 to check and it came back with 150 hp 4cyl naturally aspirated.
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Noted ... my error as searching online - Google kept changing the Engine type .... I just then cut and pasted from the online search... without checking the spelling ... tried agin now and same again ... Google changed TMD to TAMD ...

BUT found this :

https://www.storebropassion.de/boote/volvopenta/programm1989.pdf

and it lists TMD41 as 6 cyl (219 cu.in) on page 7 .....

As you say - adverts says : Volvo Penta TMD 41 from 2006, INU DP 90

Which so far I have been able to translate to a TMD41 (cylinders ?) INU as a format of injection type .... DP-90 as a possible Duoprop ...

???
 
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Refueler said:
1. RTFM is a zero answer as it has no info at all ... Volvo say they wont give figures as they don't know what boat its fitted to.
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I support your cynicism about AI, its often right but when its wrong it is usually quite convincingly wrong, which is the most dangeroind type of wrong.

However VP usually do provide fuel consumption data in terms of L/h at particular revs - eg is this the engine you have? http://goldcoastpower.com/brochures/VOLVO TAMD41M Brochure Specifications.pdf

To convert that to L/NM you obviously do need to know something about your cruising revs and either cruising speed or the gearbox and prop dimensions

Assuming that spec sheet is for the right engine then your guesstimate of 30L/h looks about right.
 
Well Paul, if you ask AI a VERY simple question as Refuler did, in a matter of seconds, if you intelligently ask it what you want to know, it comes back with about the best answer you are going to get as in this case.
Intelligence is the ability to acquire knowledge and skills. Knowledge is stuff which is known. The clue is in the first four letters. That is the basic thing that AI does.
This question is a bit like asking what the product of 2+2 is. It is known. It went directly in this case to about the best source there is for the information which had escaped Refuler. I am not quite sure what else you can expect it to do.
I suspect VP did quite a lot more work than most of its customers would in producing the graph it came up with. It completely answers the question that he asked despite the fact he thinks VP wont answer it. It provided a lot more info besides.
Yes you can ask a lot more complex stuff as did DeepMind did WRT protein folding and took what we knew to predict a couple of hundred million more protein structures. That is AI two years ago.
My point is for the simple stuff why bother with a forum when you have the answer in your hands. Even a little more complex stuff I would turn to AI first. Say you want an explanation of the Coanda effect I would turn to AI and would get a concise explanation quickly. I wanted to know where Max Q for Starship occurred. It gave me a good answer. Or ask it "What is the best route for an Atlantic crossing to Jamaca in July and what issues."
Where this forum is useful is for all the opinion and experience related stuff. Someone wanted recommendations for a bent prop. Ideal.
 
Hi !

The "dp-90" drive is most probably a typo and means a 290 duoprop .

I had a seatrail with a 36feet 8.5 tonnes flybridge and twin ad41 / 290 drives . It had flowmeters installed , i looked there but it is not quaranteed they showed correct . The engines had to work hard to bring and keep the boat on plane but appeared to be overall great engines. Flow was about 65 litres on both at 3500 which was around the lowest setting to keep the boat on plane . Props were correct for a wot of 3800-3900 .

I assume for your setup similar values / 2 for a single engine .

Hope this helps
 
Doesn't matter if it's the 150hp TMD41 or the 200HP TAMD41, it will be underpowered. 200hp TAMD 41 in that boat will burn about 35lts an hour at a steady cruise speed.

BTW, the trailer isn't a road trailer, you'd need a small lorry to tow that on the road.
 
aerobat said:
Hi !

The "dp-90" drive is most probably a typo and means a 290 duoprop .

I had a seatrail with a 36feet 8.5 tonnes flybridge and twin ad41 / 290 drives . It had flowmeters installed , i looked there but it is not quaranteed they showed correct . The engines had to work hard to bring and keep the boat on plane but appeared to be overall great engines. Flow was about 65 litres on both at 3500 which was around the lowest setting to keep the boat on plane . Props were correct for a wot of 3800-3900 .

I assume for your setup similar values / 2 for a single engine .

Hope this helps
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If fitting one engine halve the fuel bill we'd all be tearing one out 🤣
 
ss2016 said:
Well Paul, if you ask AI a VERY simple question as Refuler did, in a matter of seconds, if you intelligently ask it what you want to know, it comes back with about the best answer you are going to get as in this case.
Intelligence is the ability to acquire knowledge and skills. Knowledge is stuff which is known. The clue is in the first four letters. That is the basic thing that AI does.
Click to expand...

So I asked ChatGPT the following question:

What would you expect the fuel consumption to be on this boat? https://www.blocket.se/annons/gotland/motorbat_hso_30_1981/1401971628

I thought that is a good test of intelligence - can it work out the link is about the boat, can it find the engine in the spec, can it then tell me a sensible answer.

It answered in Swedish! Now that makes sense to the extent that the website was .se but I asked my question in English. The answer does appear to be discussing fuel consumption. So I asked for an answer in English…

It does give values which seem sensible in a neat little table. It then goes on to explain the working like a diligent student. It slightly oddly begins by discussing the number of pounds of fuel it would use, then calculating the number of gallons (they are US gallons although an intelligent system would know I was in the UK so use appropriate units!). It does explain that Volva Penta TMD41 uses 0.4 pounds of diesel per horsepower per hour.

I suspect that number is a generic value for all diesels rather than specific to the TMD41.

So I asked it:

Can you tell me where you found the 0.4 pounds/hr/HP for this engine and how does it compare to other models?

And it replied:

This figure is a general benchmark used in marine diesel engine performance calculations. Specifically:
  • 0.4 pounds of fuel per horsepower per hour (lbs/hp/hr) is a typical Brake Specific Fuel Consumption (BSFC) value for older, naturally aspirated or early turbocharged diesel marine engines running at or near peak efficiency.
It’s not specific to the Volvo Penta TMD41, but it’s a reasonable average used when exact BSFC data is not published by the manufacturer.
…
…

And then provided more rule of thumb data and waffle about why fuel efficiency wasn’t the be all and end all but then, and this bit really makes me laugh it finishes off with:

If you’re looking for real-world numbers, you could:
  • Look up the Volvo Penta TMD41 workshop manual (some versions include fuel consumption tables).
  • Ask owners in boating forums like Boatdiesel.com or MarinForum.se.
  • Install a fuel flow meter (e.g., NMEA 2000 system) for precise measurement onboard.
Whilst some people use AI like a search engine, you need to be careful. Large Language Models like ChatGPT are not actually as intelligent as the seem. The use statistics to guess what the most likely words are in the answer but that doesn’t necessarily mean that everything written comes from the same source or belong to be combined together. It is not truely intelligent, it doesn’t learn from its mistakes. It bears a lot of resemblance to a politician - it will provide a long confident answer to a question, which if you know no different might make you sure they know what they are talking about. But if you know which questions to probe with might suddenly seem flimsy. It might even “accept” its answer was not what you wanted and give a better one. But Ask it the same question the following day and you’ll likely get some variation of the partly line.
 
PaulRainbow said:
Doesn't matter if it's the 150hp TMD41 or the 200HP TAMD41, it will be underpowered. 200hp TAMD 41 in that boat will burn about 35lts an hour at a steady cruise speed.

BTW, the trailer isn't a road trailer, you'd need a small lorry to tow that on the road.
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We will be having a look at her soon .... all depends on travel plans ... I have to travel soon for business and this may delay checking out the boat.

As to trailer .. I'm not worried about it - TBH ...

Gotland is a bit awkward because by road - it needs two ferry's .... Gotland to Sweden ... Sweden to Latvia. As regards towing .. depending on weight etc - it may be able to utilise my Range Rover .. but I suspect it will be a flat-bed truck to carry both boat and trailer combo.

If the weight is ?? - then it could be a fill the tanks and motor her across Baltic. Then go with RR to bring back the trailer. If as it probably is a yard trailer - I can bring it here on a short 5 day exception .. its an exception to allow import of trailers without local registration .. just needs Bill of Sale to show its from outside Latvia.
Would be nice to have a trailer ...
 
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