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Alternating Fuel Tanks

Discussion in 'Technical Discussion' started by Thub, Jun 7, 2010.

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  1. Thub

    Thub New Member

    Joined:
    Dec 25, 2009
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    3
    Location:
    Bayfield, WI
    I recently bought a 36 Bertram with twin cat diesels. It has one large 210 gallon tank aft and two 90 gallon tanks in the bow which are tapped into one fuel line and run back to the diesels. My question is which tanks should I primarily run the engines off of? As it sits right now, the starboard engine and generator are running off the aft tank and the port engine is running off the tanks in the bow.
    Thanks
  2. Pascal

    Pascal Senior Member

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    Feb 29, 2008
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    8,546
    Location:
    Miami, FL
    that's fine.. this way each engine is fed by a separate tank and you're keeping it pretty even. that's how I run my Hatteras (two tanks on centerline)
  3. NYCAP123

    NYCAP123 Senior Member

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    Mar 14, 2008
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    11,208
    Location:
    Long Island, NY
    How is the boat's attitude? On a 36 SF it may benefit from weight in the bow, getting you on plane faster and giving you a more comfortable ride especially in a head sea. In that case you may want to run off the main tank and use the bow tanks as a reserve. Experiment.
  4. Capt J

    Capt J Senior Member

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    Jul 11, 2005
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    Fort Lauderdale

    I agree also. Depending on the speed, experiment with the fuel. If the boat (SF) is 25 knots or so at cruise it will pick up speed by draining the bow first and then the stern. The faster sportfishes like the weight removed from the bow and a little trim tab to lower the bow and lift the stern to run the quickest. If it is slow to get on plane and maintain plane, then removing weight from the aft would be best.
  5. Thub

    Thub New Member

    Joined:
    Dec 25, 2009
    Messages:
    3
    Location:
    Bayfield, WI
    The boat does like a lot of tabs, in fact it has four trim tabs. On a run the other day we were experimenting and gained about a half knot of speed with the tabs about 90% down. Thanks for the information.