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cary 50 offshore express

Discussion in 'General Yachting Discussion' started by Tom Castberg, Sep 2, 2016.

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  1. Tom Castberg

    Tom Castberg New Member

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    I bought a Cary 50 last year took out 2 of the four engines and lightened up the boat to approc 22000 pounds.i replaced the TRS drives with konrads. Boat now does 28 knots with 600 ltrs of fuel.

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  2. Tom Castberg

    Tom Castberg New Member

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    The main issue now is to replace the 540 ci v8 engines with diesel engines. But not hp or which engines to go for. Anyone have any suggestions?
  3. Fishtigua

    Fishtigua Senior Member

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    Konrad and Cummins already have a tie-up together. Maybe worth talking to your Cummins area rep?
  4. Capt J

    Capt J Senior Member

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    How fast do you want to go and how much HP will the drives handle? I'd go with something like MAN v8 common rails due to weight and 900hp.....Cary did a few boats with twin 8v92's I believe back in the day.
  5. Tom Castberg

    Tom Castberg New Member

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    The cummin previous 6bt diamond series around 450 hp 3000 rpm may be option based on power to weight. The konrad 520 should be ok up 450 hp diesel. The 540 ci v8 are 550 hp each.
    I guess i need to look at lightening up the boat even more. The interior fwd cabin, sofa area and heavy wood iterior structure would less off probably anothet 500 kg. I also found over a 150 kg of ballast lead under the galley. Redicullous!
    Have removed all the old floresent tube lights. Must have been over 20 of them. Not sure if any one had owned one of these cary's but the hull need loads of hp to get out. At present with a clean bottom she will plane at arond 18 knots. Just.
    Rpm 3200. With 5 blade 19 x 19 . Max rpm light n clean 4600. Fuel burn with just the two is outragious!
    I can get a realy good price for the new steyr around 280 hp each. They are very light and the hi rpm matches the konrad 1.8 ratio.
    Hp a bit on the low side and they are not very torquey engines.
    The other thing i aso thought about was giving the hull a bit more lift by increasing the flat lift area especialy at the stern and sharpening up spray rails etc. Any other ideas out there to try and to get the best out of this old girl. By the in ruff nasty short wave sea here in asia its a dam solid boat. Infact very impressive sea handling and without getting wet from bow spray. So to me she is worth keeping.
  6. FeBo

    FeBo New Member

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  7. Jonza

    Jonza New Member

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    Hi. Perhaps the new Volvo Penta D8-600 (840 kg dry/Bobtail)? Have no idea if they will fit/match the Konrad though. I know Fountain offered the 38 or 42 with 480 hp Cummins and Arnesons but it seemed somewhat under motorized to me - just from the top of my head really since You wanted "ideas" - good luck!
  8. Capt J

    Capt J Senior Member

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    The 48' Express cruiser was built with 3 450/480 HP Yanmars and Cummins and flew.....64 mph top end, 1 mpg at 40 knots.

    Twin 250HP won't even get that boat on plane. What you need is a light/high rpm diesel with your gear ratio. I'd be looking at the highest HP Yanmars the drives will handle. They have the powerband and weight to HP ratio you need with those drives. Honestly I would've gone to heavier drives.
  9. CTdave

    CTdave Senior Member

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    I went for a ride on a 50'/quad Cary many years ago when I was running yachts in FL. I still remember that with the drives tucked in & tabs down, the boat struggled very hard to get on plane & the bow was pointed skyward.
    When I first started reading this thread, I wondered how the boat's running attitude was now that you removed all of the stern weight. I guess removing the extra ballast under the galley helped. Even with the ballast in place, the quad engine boats required 15-20% trim tabs down to maintain a somewhat normal ride, That much tab obviously slowed the boats several knots. I don't know how much money you want to start tossing into this but reworking the bottom is a big can of worms in my opinion. You're going to get into some serious money & I don't think you will see the drastic results you might be thinking of. Your money would be much better spent on the new diesels and drives. You are very limited with the drives you have & with the right setup, the bottom will be perfect just the way it is.
    If it were me, I'd be looking for a minimum of 650hp per side but if you're doing all of this work, you would be much better off in the 800hp range. Pay attention to the torque, not just the HP numbers. Big torque can spin some big props! It's a heavy boat so either way, I'd go with Arneson surface drives http://new.arneson-industries.com/?product=1 Your drives right now are limiting everything & if you upgrade just the engines, I know you will be wishing you upgraded the drives & went to bigger engines.
    With the right set up (big diesels, Arneson drives), you will have one hell of a nice, reliable, stable and fast boat! Good luck & keep us posted on your progress!
  10. Tom Castberg

    Tom Castberg New Member

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    Thanks guys, appreciate all the feedback.
  11. Capt J

    Capt J Senior Member

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    I agree with CTDave, reworking the bottom is a can of worms. I also agree the boat needs new drives and a lot more HP. Problem with Arnesons is you don't have a lot of lift from them, so need speed and big props to get and stay on plane.