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Repowering question

Discussion in 'Engines' started by Cdndewey, Oct 18, 2021.

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  1. Cdndewey

    Cdndewey New Member

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    I'm buying a 28' Silverton with a 350 Mercruiser and a Walter V drive. I would like to replace the power system eventually with a diesel.
    Anybody have experience with doing that or suggestions before I take the plunge?
  2. Capt Ralph

    Capt Ralph Senior Member

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    The Walter V drive raises the motor height pretty tall. You may be hard to find a short Diesel engine and exhaust riser to fit under the deck.
    I would measure this out first before your purchase and diesel conversion get started.
  3. Cdndewey

    Cdndewey New Member

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    Sounds good...the more information the better...thanks.
  4. Fishtigua

    Fishtigua Senior Member

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    We've fitted quite a few Hyundai straight 4 and V6 diesels to replace gas engines, either shaft drive or outdrive. Maybe worth a look.

    http://www.hyundaiseasallusa.com/
    f3504x4ps and Cdndewey like this.
  5. Cdndewey

    Cdndewey New Member

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    Thanks...I'll look into that.
  6. ranger58sb

    ranger58sb Senior member

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    I'd suggest a careful cost analysis alongside your thoughts about what you expect to accomplish (end up with).

    I know some conversions from gas to diesel can get into the $100K neighborhood -- although one of those in a 35 Bertram also included new gears, new shafts, and a new genset too -- and the boat ends up being worth not much more than it would have been with new gas engines.

    Not intending to sound negative, just offering ideas to think about...

    -Chris
  7. Pascal

    Pascal Senior Member

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    How old is the boat? Unless you find a diesel which will fit that Vee drive and shaft, I don’t see this being a viable option as the costs will quickly escalate if you have to replace the shafts, engine bed etc.

    The weight of the diesel vs gasser may also cause issues. And if you increase HP to compensate for the weight you will have to increase shaft diameter and likely beef up the stringers. Silvertons are not Bertrams....
  8. Cdndewey

    Cdndewey New Member

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    A cost analysis is a definite must. I'm retired and on a fixed income so finances definitely comes into play. My reasoning is the cost of cruising because there's lots to explore where I live. I'm not overly concerned with resale as I have a son and two grandsons that would be happy to inherit it.
    Last edited: Oct 20, 2021
  9. MBevins

    MBevins Senior Member

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    Problem is you probably won't save any money in the long run. Remember you're only working with difference in cost between the two fuels. Even with efficiency of diesel calculated in.
  10. Capt Ralph

    Capt Ralph Senior Member

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    It may be less expensive and easier to just purchase a diesel boat if you must have a diesel boat.

    For the small amount of hours that the best of seasons can offer you, maintaining a gas boat may be the better boat, short & long term.
  11. ranger58sb

    ranger58sb Senior member

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    With some (many) boats, all you have to do to save fuel expense is to slow down to under maximum theoretical hull speed. That's a displacement hull notion, but it works well enough for other hull forms, and I'm guessing it works with gas engines, too. Sea states don't always cooperate, but then again if you're not schedule-driven, waiting out weather isn't always a hardship.

    And/or just buy a diesel boat and sell the gasser. Probably less expensive than doing a conversion.

    But see what your own cost analysis says, first.

    -Chris
  12. Pascal

    Pascal Senior Member

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    that works well on pretty much all boats over 50’ where you ll get a hull speed of 9 kts and up. On a small boat like this though hull speed is going to be a torturous 6 kts ...
  13. Cdndewey

    Cdndewey New Member

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  14. Cdndewey

    Cdndewey New Member

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    Six knots is okay for me...I'm in no hurry to get anywhere.
  15. Cdndewey

    Cdndewey New Member

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  16. Cdndewey

    Cdndewey New Member

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    Out here on the west coast you can get a lot of boating in year round. The cruising that I want to do would consume a lot of gas and the fuel docks wouldn't be frequent enough for me to fuel up. Diesel will extend my cruising range and lower my costs.
  17. Capt Ralph

    Capt Ralph Senior Member

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    Are you thinking going slow in a diesel boat "will extend my cruising range and lower my costs" dramatically over gas at the same speed??
  18. Cdndewey

    Cdndewey New Member

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    Yes...6 to 8 knots is fine for me. Lots of logs and deadheads where I plan on going so I'll be in no hurry. Not to mention...I'm retired and have no urgency to be anywhere.
  19. Pascal

    Pascal Senior Member

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    8 knots is the worst speed on a 28 footer. You ll burn twice the fuel you would at 6kts.
  20. Cdndewey

    Cdndewey New Member

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    Okay...6 it is.