Engines

[veggi]

We are having a 70ft boat built, do I go for a Isuzu 55 or a Beta 50 engine, comments on sound levels and fuel consumption

appreciated.

[bottle]

We are having a 70ft boat built, do I go for a Isuzu 55 or a Beta 50 engine, comments on sound levels and fuel consumption

appreciated.

 

Hi Veggie

 

Welcome to the forum, no expert but unless you are going to use the boat on rivers a lot then I believe you may be over sizing the engine.

 

Have a look here Beta Marine just a quick look, Beta do recommend the 43 for up to 70ft but do say a 50 can be used.

 

Check the fuel consumption figures as well ie. Beta 50 @ max torque is 2 l/h as the 43' max torque is 1.5 l/h.

 

To be fair here is the Isuzu site, on there they say the fuel consumption for the 55 is 3.2 l/h it does have slightly more torque than the Beta 50

 

I am having a 60ft built and discussed with Beta the engine required as I will be using the Severn quite regularly and they said the 43 was the one to use.

[ChrisPy]

It's not really fair to compare manufacturer's quoted consumptions, and it means very little. Most vehicle derived diesel engines share a common basic design and have almost the same specific fuel consumption (litres per hour per bhp).The actual efficiency of your engine is going to be determined mainly by the choice of gearbox reduction ratio and propellor sizing.I think what I'm saying is you shouldn't choose between manufacturers on the basis of fuel consumption. Practical issues like accessibility and ease of maintenance, and availablity of spares, are probably better criteria.

Edited August 28, 2007 by chris polley

[Windjammer]

Is there a price difference to you ??

What is the warranty with each engine ??

 

I would have thought the Beta 50 in terms of power.

55 seems a bit OTT.

[veggi]

Hi Veggie

 

Welcome to the forum, no expert but unless you are going to use the boat on rivers a lot then I believe you may be over sizing the engine.

 

Have a look here Beta Marine just a quick look, Beta do recommend the 43 for up to 70ft but do say a 50 can be used.

 

Check the fuel consumption figures as well ie. Beta 50 @ max torque is 2 l/h as the 43' max torque is 1.5 l/h.

 

To be fair here is the Isuzu site, on there they say the fuel consumption for the 55 is 3.2 l/h it does have slightly more torque than the Beta 50

 

I am having a 60ft built and discussed with Beta the engine required as I will be using the Severn quite regularly and they said the 43 was the one to use.

 

Hi. The Isuzu site appears out of date as there current 55hp engine is Direct injection and the site is still showing the older indirect injection info. I have Emailed HMI engines for the latest spec.

[bottle]

Hi. The Isuzu site appears out of date as there current 55hp engine is Direct injection and the site is still showing the older indirect injection info. I have Emailed HMI engines for the latest spec.

 

Hi

 

Well spotted, must admit didn't look to hard just did some googling

[redfastlad]

Consider the Shire 45hp with the 3 alternators its a peach it will not dissapoint mine is a Trent boat and she revs to 3,000 charges the batteries via the 3 alts and heats the water atreat dont care about the consumption figure as last time out we did 2 weeks on the Trent on 12 gallons !

[Liam]

What is the 3rd alternator for?

[bottle]

What is the 3rd alternator for?

 

Hi Liam

 

1. to charge engine starting battery

 

2. to charge domestic batteries

 

3. actually 240v generator (alternator)

[jollyroger]

Pick one in the colour you like best

There is not much to choose between modern engines, they all do a similar job

[DHutch]

Yeah i was going to say, its proberbly a dometic 240v job.

- Basicaly an alternator with a build in inverter.

- I bealve they generate multiphase ac, rectify to dc, the invert back into a stable singlephase ac output.

 

 

 

Daniel

[5thHorseman]

We are having a 70ft boat built, do I go for a Isuzu 55 or a Beta 50 engine, comments on sound levels and fuel consumption

appreciated.

 

We have a 70ft and have an Isuzu 42 and find this more than adequate. 3000 rpm (when it delivers the full 42hp) produces a small tsunami on the bank so we do not use the full grunt of what we have . Pootling on the cut we are getting close to 1.25 litre an hour fuel usage this year, although difficult to be accurate as central heating comes off the same tank

The recomendation of a 250hr oil change I think is too long and so I change it between 150 and 200hrs.

Even with rivers in a near red state we have not had a problem in going against the current.

I would suggest 50 or 55hp is too much, you will waste fuel and rarely get the opportunity to use the power it can deliver.

Sound levels - I do not find a problem, we have a cruiser stern, but this is far more subjective, for which there are many solutions (see other threads).

 

HTH

 

5th

[zenataomm]

Personally I've never had more than 22hp on a 70'. A slow revver turning a big prop is more effective, easier on the ears and attracts a lot less crud on the blades. If the batteries do get low the handle starts it. Don't forget there is a maximum efficiency which is more down to the length and depth of the swim, which dictates how much water can get to the prop. After that you only waste fuel and the prop cavitates.

In the days of working canals a loaded motor pulling a loaded butty (45 - 55 tons of cargo plus the weight of the 2 boats) would go happily all day on such power, and of course the Bolinder Pup was only 9hp!

Still I doubt The Brays used their washing machine every day nor had much time to use their rivetted satellite dish with the hours they worked.

 

I like Jollyrogers suggestion, although the colour isn't going to add much to anyone's day as most engines are banished to live under a wooden box somewhere near where the drop down table and back stove should be. Oh dear I'm starting to sound like my dad, next I'll be moaning about the youth of today ............... which reminds me!!!! ...... no, no I'd better not!

 

zenataomm

[bristol & argo]

Personally I've never had more than 22hp on a 70'. A slow revver turning a big prop is more effective, easier on the ears and attracts a lot less crud on the blades.

 

Our 22hp pushes our ~40tonnes along just nicely, only it's air cooled so not so easy on the ears. Stopping on the other hand when some lunatic comes charging through a blind bridgehole without answering a hornblast, is an entirly different proposition . thats the main benefit of these modern oversized engines.

I think an extra cylinder would make my life slightly easier on our modern day canals.

 

simon

bristol and argo

[ChrisPy]

I think an extra cylinder would make my life slightly easier on our modern day canals.

I'll see if I've got a spare one lying around somewhere

[soffy]

Weve got a vintage dormans van den horst. It chuggs and at the end of a cruise you are so sleepy we have to have a snooze before going to the pub. It is a but noisy but you cant miss us.....

[tosher]

We have a 70ft and have an Isuzu 42 and find this more than adequate. 3000 rpm (when it delivers the full 42hp) produces a small tsunami on the bank so we do not use the full grunt of what we have . Pootling on the cut we are getting close to 1.25 litre an hour fuel usage this year, although difficult to be accurate as central heating comes off the same tank

The recomendation of a 250hr oil change I think is too long and so I change it between 150 and 200hrs.

Even with rivers in a near red state we have not had a problem in going against the current.

I would suggest 50 or 55hp is too much, you will waste fuel and rarely get the opportunity to use the power it can deliver.

Sound levels - I do not find a problem, we have a cruiser stern, but this is far more subjective, for which there are many solutions (see other threads).

 

HTH

 

5th

 

Hi 5thhorseman, Iam interested to know what size prop you have on your boat ? I have an Isuzu 42 on my 57 footer and can't get more than 2300rpm under full power. thanks tosher.

[Theo]

Yeah i was going to say, its proberbly a dometic 240v job.

- Basicaly an alternator with a build in inverter.

- I bealve they generate multiphase ac, rectify to dc, the invert back into a stable singlephase ac output.

Daniel

 

Isn't it the Travelpower that does the final inversion job?

 

Nick

[dor]

Hi 5thhorseman, Iam interested to know what size prop you have on your boat ? I have an Isuzu 42 on my 57 footer and can't get more than 2300rpm under full power. thanks tosher.

 

I've got a Vetus 42hp on a 57ft boat. It also maxes at about 2300 rpm under load, with a 17 x 12 prop. I've had much discussion with the builder and Vetus, the latter saying that with my engine and gearbox the prop is right. However as most of their sales are to the lumpy water brigade where this might be the case, I suggested that it was overpropped for normal canal use, as I was doing nearly 3 mph at tickover ( the engine is arguably too big for the boat, but I wanted a good reserve for tidal rivers). They eventually agreed and the prop will be changed to one with less pitch, either a 17 x 11 or 17 x 10. The reduced pitch should make it more tractable at slow speed, but still allow full power to be used by letting the engine reach a higher rev limit.

Edited September 19, 2007 by dor

[tosher]

I've got a Vetus 42hp on a 57ft boat. It also maxes at about 2300 rpm under load, with a 17 x 12 prop. I've had much discussion with the builder and Vetus, the latter saying that with my engine and gearbox the prop is right. However as most of their sales are to the lumpy water brigade where this might be the case, I suggested that it was overpropped for normal canal use, as I was doing nearly 3 mph at tickover ( the engine is arguably too big for the boat, but I wanted a good reserve for tidal rivers). They eventually agreed and the prop will be changed to one with less pitch, either a 17 x 11 or 17 x 10. The reduced pitch should make it more tractable at slow speed, but still allow full power to be used by letting the engine reach a higher rev limit.

 

Thanks for your reply, my prop is also a 17" x 12" and I have reached the same conclusion as you although my boat handles very nicely at tick over for entering locks etc. I have discussed this problem with Crowthers who were very helpfull but they say that the prop is too SMALL and they would recommend a 17 x 13 or 18 x 12 prop for a standard 57ft boat with a 42 hp engine which leaves me somewhat confused. But please keep us informed as to how your boat performs with the new prop. Thanks again - tosher

[Guest]

Interesting. My Vetus 415 (33HP 57 ft NB) never sees above 2400 RPM. Has been like that fo three years since new. OKat tickover speeds. Handles well etc. No intention of changing anyhting TBH. Nearly certain it is 17X10 prop. Often wondered if it would rev more freely in deeper water on rivers etc., but never had this boat on any yet.

Edited September 19, 2007 by Guest

[bottle]

Hi Tosher

 

See here link Beta Marine give a guide to prop sizes.

 

For their 43HP they recommend a 18 X 12

 

For their 39HP they recommend a 18 X 10

 

Similar to Crowthers

[bargiepat]

We are having a 70ft boat built, do I go for a Isuzu 55 or a Beta 50 engine, comments on sound levels and fuel consumption

appreciated.

 

Hi, You could think about a Beta JD3....................... You should have room for a seperate engine room , they are not that silent but the fuel consumption is great. I met someone on the Thames that told me he gets 0.9 litres per hour from his.

It also should go on for ever ......... I cruise at 800 revs with mine in a 60ft .

Regards Patrick.

Edited September 20, 2007 by bargiepat

[Liam]

I've only ever heard one JD3 running and it sounded a bit tinny. Probably a one off I'm sure.

[mykaskin]

We have the 1.7 litre 42BHP Isuzu in our 50 foot boat. The prop shaft installation was badly done, placed too high up and to close to the swim, so we get a bit of vibration. We purchased a smaller Crowthers high effeciency prop, which is 16x12 but equivelent to 18x12, to give extra clearance to the counter.

 

With this setup we reach 6.7 mph at 2400 rpm (flat out). We have pushed many rivers this year feet into the red including the Trent, Severn, and Avon with no problems.

 

Re: Beta JD3, these are not really anything special - just low power tractor engines, and sound like one as well. Never thought much of them, but not actually driven a boat with one.

 

Hope that helps, but probably just muddied the waters more!

 

Cheers,

 

Mike

 

BTW - We would have probably gone for the larger Beta engine if we had a boat built, but the shell already had this unit in it. We , however, do lots of tidal work including the Humber, so...

 

BTWA (By the way again) - My other boat, 60 foot, only has a Lister SR3 (17x? prop) and just about manages 5.3 mph on a good day, but is fine for canal work - just doesn't stop very well!

 

http://shoestring.zapto.org/

Edited September 21, 2007 by mykaskin