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  1. #1
    Ausfish Addict Chimo's Avatar
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    Jun 2006
    Gold Coast

    Diesel for Llittle Boats

    If someone wants to start it im more than happy to contribute some of the ideas we have.

    Cheers PB

    OK there you go;

    If one wants to avoid stern drives and big engine boxes above the floor and go diesel; how to do it?

    Maybe someone needs to convert a Subaru flat four into a diesel.

    Can you run a dry sump with a diesel?

    Sticking the engine in the mid ships and running a shaft has some appeal except for running aground which seems to be best done in outboards in the Gold Coast undredged waterways. At what point does a keel become undoable?

    What could go wrong.......................

  2. #2

    Re: Diesel for Llittle Boats

    My son in law has just got a 25' Bertram with a stuffed Volvo diesel in it, he is wondering whether to replace/rebuild it, toss it out and put a pod and outboards on it, and even though it is a tiny 4 cyl diesel motor, the engine box is gigantic, often thought about some sort of flat diesel, the Subaru engine although a flat 4, is still reasonably high from bottom of sump to top of motor, mind you, nothing like a "normal" motor, in something like the Berty, the really deep V makes for a lot of room under the floor, that a flat something would fit into very nicely.

  3. #3

    Re: Diesel for Llittle Boats

    Why re-invent the wheel? There is a production boat that fits of Chimo's criteria above, is 2.5m wide and trailerable. The 7.7m Reelax Capricorn. I just so happen to have one.

    With regard his last sentance above, this boat does have a keel guard. I have been running it up the beach at Bribie without a problem.

    On the steering thing, it is just a matter of getting used to it. I am yet to get myself crossed up yet as I am aware of it. I steer good to starboard forward and good to port in reverse. I can kick myself over to port nicely when parking on the port side with the windmell effect of the prop. A thruster would make life a little simpler. The ultimate solution is David Pleysier's Beluga rudder system. You could nearly retro fit it to mine but would be easy to do from new. It is similar to the prop tube type things on trawlers etc. Certainly all the little crab boats up here on the Sunny Coast that are single shaft drive semi displacement things get on ok and they have tighter pens than me. Plenty of plate shaft drive boats getting around at commercial ports like Burnett Heads, Hervey Bay and here at Mooloolaba.

    Mine has a prop tube similar to lots of US boats. They do a few similar. The 25' Bertie in Myles' post on the other thread is a ripper but no prop tube. The other boat bought up in that thread is the CJH Sportfisher which is a 26'er with twin diesel Yanmars under the bridgedeck so it leaves a flat cockpit. It was trailerable but extremely exxy for the size with the massive initial purchase price of the two diesels there. Leigh O'Brien of the O'Brien boat building family from Townsville did a similar thing to that 25' Bertie but in a 23' Formula. It was a single shaft diesel with Cummins power and a little tuna tower. It was a little weapon.

    The massive thing I have found with mine is the 180 degree fishability. This was pointed out to me by the old owner Peter Stevens and he is 100% right. So far I have only lost one mackerel around the prop. I'd lost a lot more on the Stabi. Pod mounted boats are pains for fishability. I don't like Jeff's transom setup at all in the other thread but he was critisising engine boxes for getting in the way. I reckon by the time they stood behind his bait esky setup then got over the outboard or cleared those boarding platforms you would be stretched. That is critism of all those Portifino transoms and full pod setups as well. My Mclay and Stabi were both full pod setups and a bit of a pain at times. The go for sterndrive diesels is jack shafting them. Plenty of examples of them. The Vasards did it and were centre mount centre cabs, had a pretty good think about a WA Chivers at one stage that was the same and I am sure there have been a few plateys like that. Build an esky box or bait station or whatever over the engine box.

    Getting back to my boat, they were probably a bit exxy back then. I think they ranged in price from $90K up. I have seen the tax invoice for mine originally in 2003 for $130K but that was in survey and it was pretty decked out with the cork cockpit and water tanks etc. That was probably a fair bit back then but talking to George from Reelax he could probably do a new one for the same sort of money or $150K or so. The biggest cost is the diesel at $30-35K. Now if 685 Cruise Crafts etc. are going for that $130K sort of money and knowing what my boat can do into a headsea due to its weight it would be an interesting decision for someone in that end of the market. That is without trailer on the Reelax but the CC would be with trailer. Certainly if you lived on the water and wanted something to live on the water without an air berth or Sea pen or whatever, diesel shaft drive is the go. It would save you $20K on the initial purchase price of an air berth or similar. For survey the diesel is highly regarded from the safety point of view. The low flash point of the diesel and on the old school diesels, so long as you keep the fuel and air up to them they should keep running as there is no electrical system needed. It is a bit different now with all the computer control stuff on them. If you rack hours the diesels are the go. I am at 7,400 hours. Doubt if an outboard would get anything approaching that.

    So short of someone marinizing a flat motor the options are big bickies like the CJH Sportfisher, boats like the Albermarles or Carolina Classics, jack shafting anything or a big platey or a diesel shaft drive like the little Pleysier or the Reelax or something custom.
    Last edited by Smithy; 06-07-2012 at 02:30 PM.

  4. #4

    Re: Diesel for Llittle Boats

    Have a look at the size of the engine box in the back of the Bertram, it is almost wall to wall, and it is a pissant 120HP 4 cylinder.
    Attached Images Attached Images

  5. #5

    Re: Diesel for Llittle Boats

    The biggest problem with most of the ones around is they are to big and heavy to tow and shaft drives can be a pain at some ramps if you do a lot of towing, if it was going to be moored i would bother with a boat under 35'

    I think the jack shaft to a leg is the way to go.
    We tried pushing the motor under the bridge sole but it played with the trim to much and the hull shape would have been more of a displacement hull rather than a planing hull, not what where looking for.

    Ive been on the Carolina Classic 25, awesome bit of gear but its huge on a trailer and pushing the 4.5t. the key is to get a mid mounted diesel around the 7.5m mark that can be towed by a LandCruiser.

  6. #6

    Re: Diesel for Llittle Boats

    i like the look of these.
    On a trailer so sterndrive doesn't matter (better) but with jackshaft to the motor midmounted (think i have seen the engine box further forward than these examples. 315hp yanmar. sweet

  7. #7

    Re: Diesel for Llittle Boats

    Get a old council bus there motors are volvo but a flat turbo 6cylinder

  8. #8
    Twin 470s were pretty standard in the B25's Noel from memory, so that is where the box size comes from.

    Jack shafts and leg would move the box forward, but would still be there. As suggested a sports bridge layout would get around the box, but only the yanks still build them it seems.

    Other than a 23/24 Searay, which was a real rock & roll boat, the only 23-25 boats that I put diesel S/D's in (with a flat cockpit) were 23/24 Fjords. Good hull but a hell of a 'coaming' to make up for the high floor.

    Marcel (CCC) was making jack shaft 4 cyl volvo DP's (130hp) in ~20 ft boats around 25 yrs ago.

    Diesels have come a long way in that time, much lighter with more power, but I would say it is the cost which has held then back.

    I love the handling benefits of a low slung Duoprop diesel (compared to O/B), but in all our shallow country it's nice to get out of shallow/tricky situations with an O/B. Universals and boots/seals don't (didn't) like that -maybe current ones are OK? That's why I have an O/B.

  9. #9

    Re: Diesel for Llittle Boats

    I like the set up of this Cairns Custom Craft, though unsure of how stable it would be at rest as the deck looks to be very high.

  10. #10

    Re: Diesel for Llittle Boats

    I'd love to get a diesel for my Vasard 7.5, its mid-mount with a 350 chev/mercruiser, jack-shafted to stern drive. But alas funds dont allow for that just yet.

  11. #11

    Re: Diesel for Llittle Boats

    If you want a lower profile deckbox over your diesel you are going to need a wider boat to give you more room under deck, which should not be a huge issue with the relaxation of overwidth trailer regulations.
    Combined with a prop tunnel & keel as shown on Rob's boat, you can run a shaft system on a small boat. The tunnel shown below is on a much larger boat & is big to accomodate the propellor.
    Given a set of drawings done by a Naval Architect, a good alloy builder will fix you up. But it will not be cheap.
    However, I have spent a lot of time on Rob's boat & his engine box is great. It is a simple system & it is 100% functional. You can access the filters, belts, heat exchanger anodes & all the other things that need to be got at from the deck.

    ROLL TIDE, ROLL.................


  12. #12

    Re: Diesel for Llittle Boats

    George Sant built the Excaliber 740 in the 80's. It was a great sea boat, and wouldn't ya know, was typically fitted with a mid mounted deisel, jack shaft, and leg. The engine box served as a game chair base or rod holder, tackle station.
    Here's one for sale, but it's been terribly altered along the way ending up somewhat useless with the addition of a second targa arch;

    And Chime, Subaru already sells their flat fours as a diesel in their cars.... so get marinising mate :p
    And yes, you can fit a dry sump to ANY engine.

    Noelm, the 25 Bert pictured is evidently using the standard issue twin Mercruiser engine box. Bloody great waste of space that.

    Does anyone remember Peter Webster's Star 7.4m tin boat? If memory serves me right it was also mid mounted/jack shaft/volvo leg equiped.
    I really don't know what we don't see more of this (Vazard included) jack shaft layout. I suspect cost is the main culprit.

  13. #13

    Re: Diesel for Llittle Boats
    anyone been in these? Any reports? I thought the price is not out there, although for that money I could think of other things...

  14. #14

    Re: Diesel for Llittle Boats

    Like those links to the Witchcrafts. Those SA guys build some good boats - think Claytons, Theodores, Northbanks etc. that we don't see up here in SEQ. Very practical commercial boats with hard tops.

  15. #15

    Re: Diesel for Llittle Boats

    what the visability like on your boat smithy ?those windows look dark

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