Narrowboat Engine

Discussion in 'DIY Marinizing' started by timswait, Jul 4, 2008.

  1. timswait
    Joined: Jul 2008
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    timswait Junior Member

    I'm considering engines for a narrowboat. It's a bit different to most of the projects discussed on here as it only needs 30-40hp to chug along. I'm after something smooth, quiet and most of all really efficient. The boat will be a liveaboard, I don't want to fit a separate generator so will use the engine for power, hence the need for smooth and efficient at low throttle openings. Will probably use 24v electrics for the boat. I'm thinking of using a fairly modern common rail direct injection diesel from a car. I'd get something like this skoda or this Pug.. Take the engine out with loom, ECU and ignition switch and put into the boat. I'd run the engine on it's own 12V electrical system with all the ancillaries from the car and then fit a 24V alternator (maybe somewhere around where the power steering or aircon pump would go?) to run the boat's electrics.
    Narrowboats tend to use a skin cooling tank, so could I just connect this up in place of the car's rad?
    Water cooled exhausts sound a bit complicated is it necessary? Can't I just use the car's silencer cans and wrap the manifold with exhaust wrap? The other idea I had was to make a jacket to go around the manifold and blow air through it which could be routed into the cabin to provide extra heating and make use of the waste heat while cooling the exhaust (a bit like a VW beetle!).
    Any comments or other ideas? My main problem I can see is mating the engine to a suitable gearbox.
     
  2. FAST FRED
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    FAST FRED Senior Member

    With the slender hull and low speed requirements 30 hp should be way overkill.

    What are the vessels dimensions , and esp what does it displace?

    My guess would be the 30hp engines are run at very low speeds .

    The only way a diesel is "efficient" is when its loaded , so you may prefer 10hp to 30, for the same speeds.

    FF
     
  3. timswait
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    timswait Junior Member

    It's 60ft long and 7ft beam. Assuming a 2ft draught that gives its displacement as around 24 tonnes (18.3x2.1x0.6). Canal boat people seem to think about 30hp is enough for chugging at 4mph, but if on tidal waters it's better to have 50hp. We would need to use the River Trent which is tidal and apparently has strong currents, so will probably need about 50hp. 50hp is about the power of a small city car, where could I get a 30hp engine even if it was sufficient?
     
  4. murdomack
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    murdomack New Member

    You would be unlikely to find a small diesel in a car, although there are 1.5 litre ones in the likes of the Peugeot 106. These give ~56 bhp at 5000 rpm, which sounds a bit fast for a boat engine, so if you kept it down to ~ 3000 rpm it might suit you.
    Most boat engines that you buy from marine engine companies are based on industrial units and will be stronger, and designed to give their best power at lower speeds.
    If you are trying to save money, or if it's just a challenging project, good luck.
    You should really be asking people with narrow boat knowledge and I have not seen a lot of discussion on here about these. Try some English sites, google "narrow boat engine", or whatever, and work through them. Here is one I opened,

    http://www.canaljunction.com/boat/problems.htm

    I would not use a vehicle exhaust pipe as they tend to be pretty thin, you don't want exhaust fumes in your boat, very dangerous.
     
  5. CDK
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    CDK retired engineer

    To obtain a CRDi engine you'd have to buy a crash vehicle, remove the parts you need and sell the rest. The scrapyard guy takes just the engine and the gearbox, rendering the engine useless for a marine conversion. You need the wiring harness and the ECU.
    Without a water jacketed exhaust the installation is very difficult. You don't want vibrations and noise, so the engine mounts and exhaust parts must be quite flexible. With a steel pipe and heavy insulation you cannot achieve that goal. Look at Lancing Marine to see which manifolds are available, then find the engine for it.
    You can install 2 alternators and use 12V batteries, the 2nd alternator must be isolated from ground and wired in series with the 1th. Then you have 12V for the engine and 24 for the boat.
     
  6. FAST FRED
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    FAST FRED Senior Member

    The US source low cost source for used diesel engines ( 30 + HP) is at the shops that install and fit reefer units to large trailers.

    $ 300 to $500 will usually get a running engine.

    These are usually Kubota or Yanmar fitted with oversized lube oil sumps.
    Larger engines may be Perkins.

    They have a std bell housing size so a cheap Hurth or used marine transmission can be fitted.

    These engines will have high time , but in the best conditions , fired off , run constantly at a good load , and maintained VERY well.

    Good hunting .

    A place that works on small diesel tractors might be a priceier source.

    An auto or light truck takeout may have a harder time hooking to a marine tranny.

    FF
     
  7. CDK
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    CDK retired engineer

    " The US source low cost source for used diesel engines ( 30 + HP) is at the shops that install and fit reefer units to large trailers.

    $ 300 to $500 will usually get a running engine.

    These are usually Kubota or Yanmar fitted with oversized lube oil sumps.
    Larger engines may be Perkins."

    That sounds like paradise to me, and probably to timswait also.
    But he is located in Europe....

    I paid almost $ 4000 for 2 very tired VW turbo diesels, one very unwilling to start because the previous owner used it without a fuel filter for who knows how long. Only when the fuel injection pump was totally clogged up and all 4 glow plugs burnt out he decided to abandon the 6 years old van. The other one came from a large organization and was properly serviced.
     
  8. AuxiliaryComms
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    AuxiliaryComms Master work in progress

    You might try reposting your question at CanalWorld.net or just browsing through the site. I know they've had a lot of talks about htier engine preferences.
     
  9. FAST FRED
    Joined: Oct 2002
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    Location: Conn in summers , Ortona FL in winter , with big d

    FAST FRED Senior Member

    That sounds like paradise to me, and probably to timswait also.
    But he is located in Europe....

    I dont know Europe but would be really suprided to hear they do nor use refrigerated trucks to move fresh produce.

    Do not phone , GO TO THE SHOP, with cash, they will be happy to dicker for what is essentially scrap to them.

    HEAR it run, before reaching for those Euros.

    FF
     
  10. timswait
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    timswait Junior Member

    Hi, I've got hold of the 'donor' vehicle that I'm fitting the engine from, a VW Polo 1.9 SDi. Not common rail, but fully electronic direct injection. Rated at 63hp, so a little over-powered, but then that's 63hp at something like 4000rpm, in the boat I'll probably never be revving it over 2000 (aim to chug along at 1500rpm mostly), so I reckon the power should be about right.
    My main question now is what to do with the exhaust. I'm using a keel cooling tank for the cooling water, and I want to keep it as simple as possible, so don't really want a wet exhaust. The simplest (and cheapest) way is to use the car's manifold, and then connect a suitable silencer and lag the whole thing. But every narrowboat engine I've seen runs the exhaust mainifold through a water header tank (something like in the picture). I guess this cools the exhaust somewhat, but how necessary is it and does it have any other purpose? My engine is beneath deck, so i'm a little worried about 'under bonnet' temperatures. My other idea was to air jacket around the manifold, similar to an old VW Beetle, and have a blower to blow air through, in the winter I could blow it into the cabin and get extra heating. Obviously I'd still insulate around the outside of the air jacket, but an air jacket would be easier for me to fabricate than one of the header tank type water jackets.
    The other thing is that in the photo of the Isuzu I've attached there's what appears a braided pipe in the exhaust. Is this a high temp flexible section to cut vibration? If so where can I get one?
    Cheers.
    Edited to point out that the white car is what I've got, not the shiny blue engine! That's just what I'm aiming for! ;-)
     

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  11. murdomack
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    murdomack New Member

    Hi

    The water header tank that I think you are talking about is probably the exhaust manifold which has the engine cooling water filler cap on it. Here is a Westerbeke one,

    http://www.marinedieseldirect.com/c...&printservice=45100&printoperators=&comment1=

    there are companies that make these in the UK like Bowman, but I don't see a VW one in their range. I'm sure someone makes them though

    http://www.ejbowman.co.uk/products/MarineHeatExchangers.htm

    Here is a website showing a dry exhaust for a fishing boat, might give you some ideas. If you have fabrication ability, make your own flanged pipes and silencer as normal car exhaust is very weak for using in enclosed spaces, remember that a leaking exhaust can kill you without you being aware that it is happening.

    ftp://ftp.fao.org/docrep/fao/field/006/ad533e/ad533e02.pdf
     
  12. timswait
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    timswait Junior Member

    Yes, that is what I'm talking about, what does it actually do and is it really needed, can I not just fit the cast iron one from the car?
    Bowman do a VW one for the 1.5 TD, and I know from this forum it also fits the 1.9 TDi, it looks like it might fit mine, although I really need to get the engine out the car so I can measure it properly to find out.
     
  13. murdomack
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    murdomack New Member

    Hi Again,

    Go back to post #5 where CDK explains a good part of the reason. There is also the heat, but you have ideas for working around that. If you want the exhaust to be totally dry you will need to fit a metalic bellows piece to cope with the vibration. I don't know how much they cost, but it's probably less than going with heat exchangers. These ones are good for 450 deg C.

    http://www.vibracoustics.com/cms/uploads/75-A-01_02 05J.pdf
     
  14. CDK
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    CDK retired engineer

    The Bowman VW150-3490 exhaust manifold with integrated heat exchanger and header tank will almost certainly fit. Designed for the 1.5 VW diesel, I used it for 1.9 TD engines without any modifications. It is a light alloy casting with rubber grommets on the cooling fluid side and a 4 hole flange for the exhaust.
    It absorbs so much heat from the exhaust gases that you can use an insulated dry exhaust pipe and silencer if you absolutely want to. At 2000 rpm I estimate the exhaust temperature to be around 200 degrees C. The penalty for that, as I pointed out earlier, is a lot more decibels because you cannot use rubber hoses.
     

  15. murdomack
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    murdomack New Member

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