Click for Furuno Click for Mulder Click for Cross Click for Westport Click for Abeking

Repower Hatteras 58 CPMY?

Discussion in 'Hatteras Yacht' started by ranger58sb, Apr 22, 2021.

  1. ranger58sb

    ranger58sb Senior member

    Joined:
    Aug 20, 2013
    Messages:
    818
    Location:
    Chesapeake Bay, USA
    Given we're not having any luck finding one of the boats we really want... due to market conditions and/or current owners who apparently haven't ever heard the words "engine service"...

    I'm thinking of Plan B... C... D... etc. One of those is about a relatively inexpensive late '70s Hatteras 58 CPMY that's also relatively nearby. It has twin 425-hp 8V71TIs, unknown hours, unknown condition...

    IF (big IF) we look into that a bit further, and then IF (another big IF) it were to eventually turn out we like the boat well enough to keep it longer than just as an interim ride... I'd like to be pre-armed with insight into repowering options.

    My first guess would be Cummins QSCs, maybe reman if those actually exist...

    But what would it take to drag the old blocks out and get the new ones in? Does anyone know if it could be done without going through the hull sides?

    -Chris
  2. SeaEric

    SeaEric YF Historian

    Joined:
    Jan 28, 2007
    Messages:
    1,360
    Location:
    out on the dock
    A friend of mine repowered his 53' Hatteras 1981 Classic with a pair of Cummins. His boat has recently been on the market - you may have seen it on the net. His boat had hatches in the deckhouse floor over top of the engine rooms. 8-71's came up and out the back doors and new Cummins back in the same way. Install was done by a yard in Selby Bay. Are you looking at a 58 CPMY or a 58 YF? 2 slightly different boats.
  3. f3504x4ps

    f3504x4ps Member

    Joined:
    Apr 23, 2012
    Messages:
    152
    Location:
    Cape Canaveral, FL
    Pascal should be chiming in soon and could give you some rough numbers, he has a 70's 53 Hatt and has done a complete repower with same engines. I'm sure if you do an internet search you could come across a few of his threads on the removal and install. He did not go through the hull.
  4. Pascal

    Pascal Senior Member

    Joined:
    Feb 29, 2008
    Messages:
    8,120
    Location:
    Miami, FL
    I don’t remember the exact layout of the 58 CPMY. The 58 Yacht fish (a 53 with a cockpit) has hatches to lift the engines out. Some other boats incl the 58 MY have the galley up so pulling the engine requires disassembling the galley

    the QSCs would be great in that boat. I repowered my 53 MY with 435hp C Series and it was well worth it. Transformed the boat. Value wise you can’t beat the Cummins factory reman program. Engines are rebuilt by Cummins, with warranty and all new parts except the block. I don’t know the costs of the QSCs. When I ordered mine 4 years ago the C-series were about $36k each with new ZF gears.
  5. Pascal

    Pascal Senior Member

    Joined:
    Feb 29, 2008
    Messages:
    8,120
    Location:
    Miami, FL
    I checked. The 58 CMY is indeeed galley up. So before opening up the engine hatches the galley has to be disassembled along with the bulkhead between galley and PH. Not a huge deal and actually a good opportunity to redo the galley as the original is likely dated
  6. Capt Ralph

    Capt Ralph Senior Member

    Joined:
    Sep 8, 2004
    Messages:
    12,649
    Location:
    Satsuma, FL
    I luv the cummins 8.3s. Would make the same HP (or more) with way less weight.
    The 8.3s made over 600hp but because of emissions was pulled back to 550. Old software is still available from the rite tech.

    Managing a boat that had 6V92s and went 8.3s Screamer. She is a 53' Southern Cross that just hit the market in Jax.
    Engine swap went straight up thru the saloon deck and roof.

    There is nothing wrong with 8V71s. Very forgiving engine and can make lots of reliable HP. Solid crank shaft that rarely has any concern during rebuilds.
    Just an old design.
    ArielM likes this.
  7. Capt Ralph

    Capt Ralph Senior Member

    Joined:
    Sep 8, 2004
    Messages:
    12,649
    Location:
    Satsuma, FL
    Is that the 58 CPMY or 58 Yacht-Fish.
    I was in luv with the 58 yacht fish till I finally boarded one,, no head room..
  8. SeaEric

    SeaEric YF Historian

    Joined:
    Jan 28, 2007
    Messages:
    1,360
    Location:
    out on the dock
    The 58 CPMY is a 53 ED with a cockpit glued on the back. Galley down.
  9. Pascal

    Pascal Senior Member

    Joined:
    Feb 29, 2008
    Messages:
    8,120
    Location:
    Miami, FL
    Lol. You are partially right... looking at the brochures on that owners website that I can not post the name of here :) ... the standard layout was galley down but Hatteras offered an optional layout with galley up and a 4th stateroom

    In any case the galley down layout (yuck never again) still has a partition and a bar over the hatches which have to be removed.
  10. Pascal

    Pascal Senior Member

    Joined:
    Feb 29, 2008
    Messages:
    8,120
    Location:
    Miami, FL
    sorry but they 8V71s don’t make a lot of HP. Even in TI form they are barely able to get a 53MY on plane.

    the C series put out the same HP as the 8V71TIs but between the engines and the mammoth Alisons repowering took 3000lbs off the boat!

    Best engines for most 53-58 hatt MY woudl be the 500hp+ QSC factory reman. These boats need 500-600hp to perform correctly and not always have the engines close to the pins
  11. NYCAP123

    NYCAP123 Senior Member

    Joined:
    Mar 14, 2008
    Messages:
    11,205
    Location:
    Long Island, NY
    I just took a fast look and found a 1977 for $150K. DK if I'd do a $72,000 repower on a 40+ y.o. boat worth $150K, and you know that's just the start of the money you'll lay out on a 40+y.o. boat.
  12. Pascal

    Pascal Senior Member

    Joined:
    Feb 29, 2008
    Messages:
    8,120
    Location:
    Miami, FL
    $72k is Just for the engines and gears. Then you have the labor to pull the old stuff... clean the Detroit mess ( decades of oil leaks), fabricate new beds, drop the new engines, put in new shafts and wheels... $72k is the easy part

    but what is the alternative? A 50’ mutt?



  13. NYCAP123

    NYCAP123 Senior Member

    Joined:
    Mar 14, 2008
    Messages:
    11,205
    Location:
    Long Island, NY
    College tuition.:rolleyes:
  14. ranger58sb

    ranger58sb Senior member

    Joined:
    Aug 20, 2013
    Messages:
    818
    Location:
    Chesapeake Bay, USA
    Thanks, all, and I'd been hoping for input from Pascal so I do very much appreciate that!

    I think I did see that 53 YF with Cummins, and I think that was why I got this hairbrained idea anyway. I'll reinvestigate the 53. Wouldn't hurt to know which yard in Selby Bay, since we're familiar with the area... and that's where we've been berthed for the last 15 years or so...

    The 58 is a CPMY, galley down. I would normally have focused first on their Yachtfish models (even though fishing isn't really my focus)... but the 58 YF doesn't have the flybridge helm aft like the 53... so I don't see any "fish" (or docking) advantage to that one. This particular CPMY has gear/throttle controls in the cockpit, probably decent for docking stern-to. And its relatively close, and relatively not hugely expensive.

    In the listing pics, I don't actually see evidence of hatches.. and I can't quite picture where they might be relative to a "partition and a bar" that would be in the way... but just knowing it likely wouldn't be necessary to go through the hull is a big step forward.

    Ref comments about value. Start with a 40+ year old $175K boat, spend $125K in repower, end up with a 45 year old $185K boat. Yep, got that. Given the 8V71s have a decent rep and are (presumably) rebuildable, I'm not thinking a repower is Plan A.

    Alternatives? Yeah, therein lies a big rub. We started with a clean sheet and the Powerboat Guide, compared our requirements to pretty much every boat within our likely price range. (Which meant I couldn't just wander over to the Sabre store and get one of their 54 flybridge models, call it perfect...) Result has been 1 very clear winner, whose only drawbacks are length (slightly longer than we wanted) and resulting price. None -- with decent owner maintenance -- within our budget, and not really many newer (more $$$) ones available either. Second best, ditto. Tie for 3rd best, getting further away from requirements... Et cetera. And even 3rd tier options are expensive enough so as to not be "temporary" solutions.

    Hence back to the thoughts about that particular Hatt 58. Wifey doesn't care for it, though. Possibly especially because of the galley-down configuration... and that wouldn't be my preference either.

    Can't tell how we'll proceed, yet...

    -Chris
  15. classic

    classic Member

    Joined:
    Oct 27, 2019
    Messages:
    58
    Location:
    ft lauderdale
    After all the hard work you will have a fanatastic boat !

    happy boating .
  16. Pascal

    Pascal Senior Member

    Joined:
    Feb 29, 2008
    Messages:
    8,120
    Location:
    Miami, FL
    Well if the boat ha s engines that need to be rebuilt it will not be worth $175k. But yes, the minute you drop the engines in, they ve lost 30% % of their value... just like when you you buy a new boat or install new electronics

    When I decided to repower my 1970 53MY, I obviously considered rebuilding the 8V71s. There were a few reasons I didn’t. First rebuilding both engines and gears would have cost $50k and labor to pull them out and reinstall them was the same as the repower. Yes i know you can do an in frame rebuilt but you still have to raise the engines to get to the bottom.

    Then a rebuilt really doesn’t come with any warranty. It s all on the reputation of the rebuilder while the Cummins factory remans have a two year factory warranty.

    also, like it or not, Detroits two cycles have fewer and fewer fans... it is 1940s technology and while parts are still available the quality has declined. New Injectors are often an issue for instance.

    and finally was the weight savings. The allisons alone weight 500lbs each. The new ZFs weight about 175 lbs...

    The biggest additional expense in a repower is having to fabricate new engines beds which isn’t that expensive anyway. Shafts usually don’t have to be replaced unless you really go up in HP. I replaced mines because they were original to the boat and two piece shafts with couplers.

    repower doesn’t allows make sense but if the boat is I otherwise good shape and can be bought cheap, it is a viable option.
  17. echo charlie

    echo charlie Member

    Joined:
    May 29, 2019
    Messages:
    47
    Location:
    Elizabeth City , NC
    What about a very late model 53 with 6V92s 465 hp , have the engines rebuilt to 550hp specs ? Should give a good performance boost .
  18. mapism

    mapism Senior Member

    Joined:
    Aug 9, 2008
    Messages:
    2,111
    Location:
    Sardinia
    I wouldn't mind their 6.7 engines either.
    Particularly on a Hatt MY, a boat which nobody in his right mind could be interested in for her speed.
    Even lighter and smaller, would make the engine room feel spacious!
    And at the end of the day, I don't think it would affect the real world cruising speed of the boat.
    What's there not to like?
  19. Capt Ralph

    Capt Ralph Senior Member

    Joined:
    Sep 8, 2004
    Messages:
    12,649
    Location:
    Satsuma, FL
    Trading a 71 for a 92?
    And you not sharing what your smoking..
  20. echo charlie

    echo charlie Member

    Joined:
    May 29, 2019
    Messages:
    47
    Location:
    Elizabeth City , NC
    Iam playing with HOUSE money .