Repower Inboard Prop Pocket Hull with Outboards?

Discussion in 'Boat Design' started by StandAlone, Feb 5, 2017.

  1. StandAlone
    Joined: Feb 2017
    Posts: 8
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Melbourne, FL

    StandAlone Junior Member

    It's not pressing at this time but with a 30 year old power train I know there are gremlins that are lurking.

    That said, I'm 50 years old, in good shape and doing the work down in the bilge is brutal especially when it's 90 degrees F and 90% humidity here for 8 months of the year. Aside from that, I don't have the time and getting quality work done around here is non-existent so far. I've already been "taken" by a highly recommended vendor. Once bitten, twice shy.

    My desire to repower is to get out in front of my aging frame and ahead of any potential problems associated with old engines.

    As for the Donks, being the land barges they are, fuel economy is not important to that set of my customers.

  2. PAR
    Joined: Nov 2003
    Posts: 19,133
    Likes: 494, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    I know just how you feel and I'm a fair bit older than you, but I still like the idea of wrestling a set of reman MK IV's back into those spaces, rather than reconfiguring for a set of diesels. Reman pricing is very low, just unbolt what you've got and swap stuff out.

    I'd also consider saving about 800 - 900 pounds and going to EFI small blocks for the same output HP. A turn key engine (new second gen block, aluminum Vortec heads and MPI) is about $10k, but the remans are easily half this. I don't think any of the major manufactures are building MK IV's any more, but the MerCruiser 8.1L Horizon is designed as a replacement for the GM big blocks. These are almost double the price of the new small blocks.

    Both the new small and big block packages are fully electronic and much more reliable than the older carbureted versions. There could be gearing issues with changes to the base engine, so the economical way to go is a long block for the MK IV's.
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