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Repower Advice

Discussion in 'Bertram Yacht' started by jacks88, Apr 11, 2017.

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  1. jacks88

    jacks88 New Member

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    I'm looking at buying a mid '80s vintage Bertram 48 convertible, but the engines are toast. I don't mind making the purchase because the seller understands and has agreed to a fair price. But, I don't really know much about this size vessel or the engines that go in it and I'm a bit nervous about taking on the project of repowering the vessel. I have been given the names of a couple of shops here in the Galveston/League City area that supposedly do wonderful engine work, but before I go speak with them about my options I wanted to get some opinions here.

    Aside from size/space/weight limitations, what is the prevailing opinion on maximum horsepower for these vessels? Should I worry about having too much engine and/or the engines shaking the boat apart? I don't intend to run WOT on a regular basis, just a casual fisherman/cruiser style use. What about too little horsepower? I certainly don't want to handicap the vessel with too little power.

    I need an education in marine power, help!
  2. bliss

    bliss Senior Member

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    Before proceeding with your purchase remember that the value of many older boats in need of serious repair is a negative number. Good luck.
  3. Pascal

    Pascal Senior Member

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    I wouldn't worry about too much power, usually space and your wallet will prevent this from happening. :) Not enough power means you ll be pushing the engines harder and cutting their life span. If you are repowering, you may bump it up a bit, don't forget these 80s sportfish were never speed demons anyway

    What is there now and what is wrong with the engines? detroits I m guessing?

    Repowering isn't a cheap project... if you can keep the same shaft and struts you will save some money

    A good option are Cummins factory remans. They offer a whole range of engines and while not new are as close as you will get and comes with a factory warranty. I m about to remove the old 8V71s in my 53 hatt MY and repower with factory reman 430hp C series and new ZF gears.

    But the price on the boat has to be really right. Rebuilding the existing DDs will probably run you $50k and a repower around $100k
  4. captholli

    captholli Senior Member

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    When you say that your engines are "toast" Just how bad are they and what make and model are they? I'll go out on a limb here and guess by the vintage of your vessel that your motors are DD 8v92's? I always recommend to assess a in frame rebuild of motors before a repower. If your engines are deemed non-rebuildable & you decide to repower than its best to install re-manned motors of the same make and model to utilize the existing geometry of your girders and foundations, shaft angle & drive line. Same make and model re-mans will use your same plumbing connections for sea water & fuel. If you decide to repower with new make and model engines than be prepared for modifications of your FRP girders, new aluminum foundations fabricated and possible drive line mods for shaft length and prop size depending on H.P and gear ratios. A naval architect will be needed to develop drawings for the modification needed.
    A repower with same make and model remanns is costly in itself. A repower with different iron will more than likely be more pain than most pocketbooks can withstand and not worth the $$ on a vessel of this vintage.
  5. AdrenalinJunki

    AdrenalinJunki New Member

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    T put you in the ballpark, a friend is repowering his boat starting next week. It's a 50' sportfish with DD 8v92's. He's going back with Cummins QSM11 remans and ZF gears with trolling valves. It's going to be just a little over $140k.
  6. Trinimax

    Trinimax Senior Member

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    If you are referring to a bertram 46. I have read of a few that have been repowered with qsmll cummins in the 660-700 hp range. This seems to be a good choice of power for the hull as the boat will cruise in the upper 20's and top over 30 kts. Another great bonus is that the qsm11 is much smaller in size than the 8v92 or 8v71 detroits which is what this boat would have originally been powered with. I have seen pictures of 46 berts with this power and the engine room access is night and day compared to the detroit powered boats. Good luck with your project
  7. Capt Ralph

    Capt Ralph Senior Member

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    We are pretty sure they were Detroit's but still not positive.
    Would like more info on what you really have and define toast.
    There were some ole Berts that had Cummins power.
  8. C team

    C team Senior Member

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    Pascal, not to hijack this thread, but a friend of mine recently repowered his 53' Hatt MY with Cummins. He also got rid of the old Detroit's and could not have been happier!
  9. slipkid

    slipkid New Member

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    No offense, but how do you know the seller has agreed to a fair price if you don't know the cost of the repower???

    If the motors really are "toast" and you want new engines your repower is probably going to cost significantly more than the value of the boat. Not saying you shouldn't do it but you should be getting the boat for almost free.
  10. Ormond Bert54

    Ormond Bert54 Senior Member

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    Also, when considering a boat with engines that are toast, it's a boat that might have been sitting for awhile. A boat like this might need new electronics, new toilet systems, new helm, new autopilot, new bathroom fixtures, new paint, refinished brightwork throughout. In other words ... a total refit for many hundreds of thousands of dollars. Ask me cause I did it! It's far less expensive to purchase a boat that is functioning perfectly in every way. A boat this has been meticulously maintained and upgraded over the years.
  11. Capt J

    Capt J Senior Member

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    I agree with this. Problem is if you totally go through and resurrect something like this 46' Bertram you will never recover more than 1/2 your money, if that. So, unless you plan on keeping it a lot of years, I wouldn't recommend going that route. The 46's were never a great boat IMO anyways. My recommendation would be going with a lot newer 50' Post that's in working order, which is a far superior boat to the 46' Bertram in speed, efficiency, ride, room inside and layout.
  12. Capt Ralph

    Capt Ralph Senior Member

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    10 post later, the OP has never come back with answers or details.