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DD 8.2L TI difficult fixing

Discussion in 'Engines' started by Obi Wan, Nov 5, 2012.

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  1. Obi Wan

    Obi Wan New Member

    Joined:
    Nov 5, 2012
    Messages:
    3
    Location:
    Italy
    Hallo,

    I'm the lucky owner of a 1990's Trojan 34 SE powered with twin DD 8.2L 300 hp. Engines have quickly start, fast acceleration, don't smoke too muck, don't eat oil. They have been rebuilt by the precedent owner and ran about 250 hrs after the job but nobody has been able, here in Italy, to fix them to give the original RPM under load. The best result we got is 2900 RPM. First to be rebuilt they ran at 3200 (I still don't understand the reason he rebuilt two engines like those at 3500 hrs, but he was a maniac...).
    Do someone have experience on fixing of these engines? Do you know if it's possible to find service manuals in USA knowing serial numbers?
    Thank you everybody and sorry for mine imperfect language. :eek:

    Alberto
  2. K1W1

    K1W1 Senior Member

    Joined:
    Sep 30, 2005
    Messages:
    7,394
    Location:
    My Office
    Hi,

    If they run well and make the rated speed in neutral you should look at the props and how heavy the boat is now compared to how it was when it last ran WOT.

    Boats pick up weight in time, props get covered in growth, they might not even be the correct pitch props.

    One sure way to rebuild your engines early is to run them over loaded a lot,Props that are too big is an easy way to do this.

    there is another member here who re built a pair of these , he is in Sweden and might copy his manual for you or tell you where to get one. I think his name is Onerios
  3. Obi Wan

    Obi Wan New Member

    Joined:
    Nov 5, 2012
    Messages:
    3
    Location:
    Italy
    Hi and thank you for your help.

    I thought to a problem about props too, but they are not changed and the boat ran at 3200 with the same props. I don't think they are too big because when I touch trottle acceleration is really snapshot and engines run always relaxed (you can ear this).
  4. sunchaserv

    sunchaserv Member

    Joined:
    Dec 16, 2011
    Messages:
    140
    Location:
    Carefree, AZ
    KIWI may be correct regarding over loaded. How do you know they ran at 3200 RPM loaded before you bought the boat? Have you checked tachs for accuracy with a phototach?

    boatdiesel.com has many 8.2 owners and a large archive of issues and questions you could read through
  5. Obi Wan

    Obi Wan New Member

    Joined:
    Nov 5, 2012
    Messages:
    3
    Location:
    Italy
    Immediately after the rebuilt they did 1800. After the first fixing job 2200. After third (now) 2900. Obviously props are not changed. It's a fixing problem, I'm sure. Tachs have been checked.
  6. dennismc

    dennismc Senior Member

    Joined:
    Jan 29, 2009
    Messages:
    1,175
    Location:
    Vancouver BC
    I would join boat diesel , get the ser #'s etc and post the questions, also, be sure to check if that series had cylinder head bolt problems before running wot
  7. CaptOz

    CaptOz Member

    Joined:
    Apr 13, 2009
    Messages:
    100
    Location:
    Miami, Fl
    What Size are Props?

    Hi,

    What are the dimensions of your props? And what is the Gear Ration on your transmission?