Classic Offshore Racing Boat. Inboard to Outboard Conversion. *Project*

Discussion in 'Powerboats' started by Forsmanni, Feb 4, 2022.


What engine setup would you choose for this boat?

  1. Diesel I/O

  2. Petrol I/O

  3. Single OB

  4. Twin OB

  5. Something else?

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  1. Forsmanni
    Joined: Aug 2020
    Posts: 12
    Likes: 3, Points: 3
    Location: Finland

    Forsmanni Junior Member

    My newest project will be a big project so I decided to make a thread about it. If someone is interested to follow along. Im also making videos to Youtube about all my projects: @BCB Boats Garage.

    So this project is about old Smuggler 28 C2 powerboat. These boats were made in Sweden and these hulls were called "The fastest boat in Scandinavia" back in days. Many national and international victories and also a World record.

    So this boat is 28ft long and it weights about 1250kg (2750lbs). Today these (almost) same boats are still manufactured by Segmo boats.
    This specific boats previous engine setup was Volvo-Penta Diesel engine (sterndrive). My plan is to make Outboard conversion for twin outboard engines (or one bigger OB). Plan is also to remove the old enginebay and make this a 7-seater. Im also going to do the engine bracket / pod myself.

    To Do list for now:
    - Find the engine / engines
    - Design the bracket
    - Make the bracket (fiberglass)
    - Check and fix all rotten stringers / transom
    - Patch the transom / sterndrive hole
    - Reinforce the transom
    - Find and install gas tank
    - Make new floor
    - Chop the windshield
    - Make new instrument cluster (Carbon fiber??)
    BMcF likes this.
  2. bajansailor
    Joined: Oct 2007
    Posts: 3,650
    Likes: 1,594, Points: 113, Legacy Rep: 37
    Location: Barbados

    bajansailor Marine Surveyor

    Re the previous engine installation, was this a single or twin I/O set up?
    It sounds like it was a single?
    What was the power of the Volvo diesel?

    There is a lot to be said for keeping the existing arrangement, re less re-fit work to do.
    But if the existing engine beds / stringers are rotten and need to be replaced anyway, then yes, it would be worthwhile looking at having single or twin O/B motors on a pod.
    I think I would prefer to have twin O/B motors, but I suppose it will come down to the cost of a single larger engine vs twin smaller engines.
    If you do decide to build a pod, how are you going to go about designing it?
    Be aware that there will be huge forces involved with a pod - you want to make it strong enough to meet the anticipated loads, with a good safety factor thrown in as well.
  3. Forsmanni
    Joined: Aug 2020
    Posts: 12
    Likes: 3, Points: 3
    Location: Finland

    Forsmanni Junior Member

    UPDATE #1

    I found the engine for this boat. So I did some calculations and I would have needed L-shaft (20") engines if I had gone with twin engine setup (otherwise COG would have gone so high that the boat would have probably become very unstable at high speeds. It is very difficult to find "big" V6 outboards with L-shafts in a good price here where I live, because most of them are 25" shaft motors. Luckily I found in a decent price a Yamaha 350hp V8 Outboard with 25" shaft. So Im going with single engine setup! :) Yamaha V8 weight is aprox. 360kg (800lbs) so I need to make very Tuff transom and bracket. Cant wait!

    Single I/O was the previous engine. These boats have been sold/driven with single and twin OB and I/O setups.
    Im not doing this project because of rotten stringers :) Just because I like making these Outboard conversions. It makes the boat so much better in certain matters.
    And yes Im going to design and manufacture the Pod / bracket myself (Not first time). I have not decided yet if I will make it out of Stainless steel or Fiberglass.
    I think Im going with plywood core + Fiberglass. Not the best way, I know. But Easy, cheap and good if properly done.
    bajansailor likes this.
  4. fallguy
    Joined: Dec 2016
    Posts: 7,766
    Likes: 1,722, Points: 123, Legacy Rep: 10
    Location: usa

    fallguy Senior Member

    EB7C2B27-5AD5-461A-AA75-7C7B5277B76F.jpeg I made a carbon/aramid console. It was tricky, but looks good. I have to finish the teak and caulk it. Spilled some steering oil on it. The steering and binnacle bases are bedded in butyl and it is too cold to mess with so looks bad. High of 14F here today!

    DogCavalry and bajansailor like this.

  5. BMcF
    Joined: Mar 2007
    Posts: 1,191
    Likes: 195, Points: 63, Legacy Rep: 361
    Location: Maryland

    BMcF Senior Member

    I'm with you there. I bought a heavily built early 1980s 25' Deep-V Rampone that had originally been built with a pair of Volvo 140HP gas engines, straight drive w/ transom-hung rudders. I installed a pair of 150HP Yamah outboards on a transom bracket. Handling didn't change but the top speed went from 28 mph to 42 mph!
    bajansailor likes this.
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