Ok complete change of plan

Discussion in 'Boat Design' started by Boston, May 4, 2010.

Thread Status:
Not open for further replies.
  1. Brian@BNE
    Joined: Jan 2010
    Posts: 262
    Likes: 13, Points: 18, Legacy Rep: 151
    Location: Brisbane, Australia

    Brian@BNE Senior Member

    Boston, masalai is probably still rolling around the floor laughing - so I'll fill you in. This is what a saildrive looks like - no wind or sails required!

    You were gung-ho on bigger versions of the concept before your change of plan. Saildrive is available at least up to 75HP. If you're still in 'junkyard wars' mode then buy a used leg & sit your tractor on top of it.
     

    Attached Files:

  2. masalai
    Joined: Oct 2007
    Posts: 6,818
    Likes: 121, Points: 0, Legacy Rep: 1882
    Location: cruising, Australia

    masalai masalai

    And you do not necessarily have to fit a very expensive folding propeller, but they usually have sufficient clearance to enable fitting a decent sized wheel (my little 21hp sail-drives will easily accommodate a 15" propeller....)
     
  3. Boston

    Boston Previous Member

    my bad I thought the one he was talking about was one of those electrics that produces juice while under sail power by drawing energy from the motion of the prop

    this particular boat is balanced around the engine and I dont think I can alter than much and still maintain a level of stability
     
  4. FAST FRED
    Joined: Oct 2002
    Posts: 4,519
    Likes: 111, Points: 63, Legacy Rep: 1009
    Location: Conn in summers , Ortona FL in winter , with big d

    FAST FRED Senior Member

    "will fuel be available in 2 to 5 years when USA is busted and broke?"

    HMM, so far the price of gasoline and diesel had been cut in HALF

    The next bunch of US politicos will probably work hard to remove the law from using the 85% of US coal, oil, tar sand and natural gas that is currently locked up.

    . That might be good enough to get regular for .99c a gallon again!

    Hell its Alaska for Petes sakes Im sure I could use the extra heat and if not I'll run the coolant through the hand rail just a Mark suggested.

    Doe most boats a couple of lengths (21ft) of 1 1/2 or 2 inch galvanized pipe will cool just fine ....in FLORIDA, should be a lot easier in AK.

    Keel cooling does have one danger , OVER COOLING, a simple thermostat (COTS) and housing will solve the problem.

    FF
     
  5. Pierre R
    Joined: May 2007
    Posts: 461
    Likes: 32, Points: 0, Legacy Rep: 458
    Location: ohio, USA

    Pierre R Senior Member

  6. Boston

    Boston Previous Member

    good call
    yes that was my thinking entirely
    simple and straightforward system with a regular old auto thermostat regulating the heat being bled off to the larger coolant reservoir in the hand rail. I'll run three small radiators throughout the vessel and regulate the temp by adjusting the flow with a simple valve, I'll also have one of those dickenson diesel heaters for when Im not under power. That way I'll have a back up heating system if I ever need it and i can still lounge on the hook and be nice and warm.

    the sail drive thing kinda had me going there for a while, I was thinking all along that they were located at the very back of the vessel, I think what confused me was that Mas had shown a version of he torquido's that flip up and out of the way when under power and I had the two systems mixed up.

    oh well live and learn
    B

    John Deere 75hp diesel engine 5030T
    I'll have to ask the guys at the used tractor place about it
     
  7. Easy Rider
    Joined: Oct 2009
    Posts: 920
    Likes: 46, Points: 0, Legacy Rep: 732
    Location: NW Washington State USA

    Easy Rider Senior Member

    Brian,
    Can you get the sail drives w counter rotating propellers?
    Two of those in my boat would be wonderful.
    BUT THE COST!

    Easy
     
  8. masalai
    Joined: Oct 2007
    Posts: 6,818
    Likes: 121, Points: 0, Legacy Rep: 1882
    Location: cruising, Australia

    masalai masalai

    Easy, simply answered - NO - why counter (volvo system) when you can fit a single BIG efficient wheel? - have you seen 20 to 50hp outboards offering 15inch wheels as standard ??? for "displacement speed" boats - pull the **** off a bull...

    Oooops sorry Ahhh write in haste etc... The penny dropped... Why not send an email and enquire... Contact Stewart http://seawasp.com.au/contact-us.html and mention that you got it from my wrap in my website here http://boats-n-stuff.com.au/forum/index.php/topic,2.270.html - To view the images you need to register - same system as here...

    When I bought mine, I was told that the installation of a counter rotating propeller pair of engines would have almost nil impact on manoeuvrability or performance of a cat... and almost the same on displacement mono designs operating in and designed for that speed so I did not research any further...
     
  9. Brian@BNE
    Joined: Jan 2010
    Posts: 262
    Likes: 13, Points: 18, Legacy Rep: 151
    Location: Brisbane, Australia

    Brian@BNE Senior Member

  10. Boston

    Boston Previous Member

    ya cost is nuts
    I can get the engine Im thinking of for about 5k used
    course I will probably get one factory rebuilt but still
    way cheaper than 32k
     
  11. masalai
    Joined: Oct 2007
    Posts: 6,818
    Likes: 121, Points: 0, Legacy Rep: 1882
    Location: cruising, Australia

    masalai masalai

    That is Australian $ which, when the banksters of NY are not manipulating the markets, usually sits around 75centsUS = Au$1.00 (about US$24,000 for TWO (2)), including complete OEM kits of pumps, fuel lines, filters, wet exhaust, mounting module, folding propellers - EVERYTHING... except the through-hull fitting for the above-the-waterline exhaust...
     
  12. Boston

    Boston Previous Member

    its still a lot of money Mas and not something I can easily afford even if I am raking in cash at the moment
    I was thinking that a tractor motor with a marine transmission just as Apex said and then my breakaway prop system will cost me half that. Assuming I can find the marine transmission at a descent price. The engine is all of 6k new but its the trany that is worying me cause I have yet to find one or even identify which one I should be looking for

    kinda spooky if its really all that hard to find , exactly not what I want in my mechanical systems. There must be some kind of super common transmission in that power range I can take advantage of for me build philosophy of off the rack and readily available parts
     
  13. masalai
    Joined: Oct 2007
    Posts: 6,818
    Likes: 121, Points: 0, Legacy Rep: 1882
    Location: cruising, Australia

    masalai masalai

    Look over my build posts, I was vacillating all over the place in deciding on engines and my only concern was trying to keep WEIGHT DOWN, and in the end have the second heaviest option ??? at 144Kg each...

    My final came down to readily available modern production series with enough hp - The idea being to be able to access spares in all of the cruising areas - from India through to about the dateline in the Pacific... The light tractor series from Kubota won hands down...

    A non-marinised engine would be off my selection list except as a genset if larger electric drives were my selection... I feel a wet exhaust and heat exchanger cooling the best option for direct drive (not electric generator/electric drives) as the engine would be down in the bowels of the boat and the wet exhaust should afford quieter operation? - - - - It is your build, in the end, just have a good look around and choose carefully, the differences are more than just wet or dry exhaust, and to buy with a MATCHED gearbox will ba a significant advantage in installation and later maintenance, like changing the oil... a sump pump is a key component in marinisation as are significantly better fuel and lube-oil-filtering - mounted on wall of "engine-room"... A big engine will burn more fuel than a new and small one suited to the performance parameters you require... "Flank-speed" is only needed by those who do not plan ahead and have a panic attack...
     
  14. Boston

    Boston Previous Member

    ya my take is the weight must be similar or less than the original spec on that engine.
    I'm going to be building a slightly scaled up version so I can add bulk to the hull and be safer from potential penetrations from debris in the water.
    Call it paranoia but I'd rather be more able to handle a strike than less.

    the engine is pretty easy to pick from a farm boys point of view but the trany I am guessing needs to be a custom, simple really, two gears and a neutral. cant be that expensive.

    I'll have to call tomorrow and see what the damage might be

    oh well

    still working out what kind of electrical system I want
    options are to run an inverter or off of a generator

    generator is actually cheaper but that inverter might just come in handy so I need to weigh my options and see what I come up with

    less batteries involved in a generator I suppose
     

  15. masalai
    Joined: Oct 2007
    Posts: 6,818
    Likes: 121, Points: 0, Legacy Rep: 1882
    Location: cruising, Australia

    masalai masalai

    The gearbox must also be able to take a thrust bearing as the prop pushes ALL the load onto that bearing (forward & reverse)... - - - THAT is the KILLER difference - - - and why I like sail-drive for the simplicity of its installation and NO alignment issues.... - - as misalignment cannot be compensated by other "shaft alignment" tricks as the thrust of the propeller must be directed squarely and evenly into the thrust bearing...

    At least that is my amateur understanding... :D

    Inverter means batteries and no need to run an engine All the time you need some power, A genset means running an engine ALWAYS when you need power... The desire for quiet and peace whilst anchored up with 2 black balls hanging vertically to indicate "Not under Command" so I can sip some ale and not risk the thought police booking me for DIV (Drunk In-charge of a Vessel) I went the battery option with 600AH there and a 4000W inverter drawing on the 24V battery bank - Most of ships services are 24VDC, Galley and domestic lighting is mains 240VAC... I think there is only one item (Autopilot? or is it VHF radio?) that requires 12V, and I am looking at options there... but a 12V circuit from the engine management/start is OK too...

    I do not have a separate generator now but have 11 x PV panels delivering 175W each to charge the batteries (nominally some 14KW charge capacity per day whilst at rest and enjoying the peace and quiet) except when I am "making water" with the RO machine...
     
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.
Thread Status:
Not open for further replies.