Jack Shaft Setup?

Discussion in 'Propulsion' started by savagescout, Dec 15, 2011.

  1. savagescout
    Joined: Jun 2009
    Posts: 37
    Likes: 0, Points: 6, Legacy Rep: 10
    Location: australia

    savagescout Junior Member

    Hi,

    I have a 26 foot half cabin sterndrive that I am restoring and am at the stage where the floor has been completely gutted and stringers/bearers are about to be replaced. I plan to power this project boat with a 220hp Mercruiser 4.2Litre turbo diesel of which I am going to be rebuilding like new.

    Whilst I have the boat completely gutted, I was interested in investigating moving the engine towards amidships by approximately 2 feet to clear the transom area and allow me to fish around the engine box and run a jack shaft back to the bravo 2 drive.

    What I don’t know is how to set up a jack shaft as they are very uncommon in Australia.

    I presume I would need to fabricate some rear engine mounts, run the exhaust somewhere, fabricate some way of connecting a drive shaft to the rear of the engine and then in turn to the drive unit. Can anyone provide any more information as I would really appreciate some assistance during this planning/design phase.

    Nick
     
  2. whitepointer23

    whitepointer23 Previous Member

    google mercruiser jackshaft kits, you can buy everything you need. i have made my own but not for a mercruiser. what brand and model of boat is it.
     
  3. savagescout
    Joined: Jun 2009
    Posts: 37
    Likes: 0, Points: 6, Legacy Rep: 10
    Location: australia

    savagescout Junior Member

    Hi there, thanks for the reply, the boat is a Savage Scout 23 that has had a 3 foot hull extension to turn it into 26 feet.

    Seeing your signature, it appears you have a Savage Lancer, so guessing we have similar boats...

    I would be interested in going down the path of making one if it is achievable as the kits I have seen are $4000USD!
     
  4. whitepointer23

    whitepointer23 Previous Member

    yes , thats a bit pricey.
     
  5. Willallison
    Joined: Oct 2001
    Posts: 3,590
    Likes: 130, Points: 0, Legacy Rep: 2369
    Location: Australia

    Willallison Senior Member

    I almost bought a Scout once - fabulous boat - and my parents had a 26' Sonair, which was a custom build based on the Lancer hull.
    I'm guessing that you are installing the diesel because you've managed to aquire one for not much $, but have you ever thought of putting an outboard on the back instead? That would free up an enormous amount of cockpit space (admittedly not around the transom). I'd wager that with the lower weight and economy of the current crop of 4-stroke / Dfi 2-stroke outboards, it would be just as economical as the diesel too.
     
  6. savagescout
    Joined: Jun 2009
    Posts: 37
    Likes: 0, Points: 6, Legacy Rep: 10
    Location: australia

    savagescout Junior Member

    Yes i have picked up a diesel for a bargain price and like the reliability and lower centre of gravity that it will have to offer. I wanted to determine whether a jackshaft system is something that can be made up or can you only do an off the shelf type system?

    Cheers,

    Nick
     

  7. powerabout
    Joined: Nov 2007
    Posts: 2,925
    Likes: 66, Points: 48, Legacy Rep: 719
    Location: Melbourne/Singapore/Italy

    powerabout Senior Member

    You can make some of it but buy the support bearing assembly that mounts to the transom bracket at least.
     
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