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Re-power 36' CCRoamer w/GM6v53

Discussion in 'Chris Craft Roamer Yacht' started by Ray Powell, Mar 5, 2011.

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  1. Ray Powell

    Ray Powell New Member

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    Looking at 36' CCR that is repowered with a single GM6V53 with velvet drive tranny. Its aluminum boat.
    Owner states is has been in water for trial run & performed just fine. He thinks it'll run 10-12 mph for 1K miles on 250 gallons. Sound reasonable?
    It is a marine engine. I am concerned about the navigatableabilty on rivers.
    We presently has 21' cuddy & done 1K river trips.
    We're new to this adventure. Appreciate any advice.
    Thanks, Ray
  2. K1W1

    K1W1 Senior Member

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    Hi,

    Does the thinking process he refers to give any indication that there might have been some type of mechanical flow metering done which will give 4 mpg to that boat?

    To try and calculate the fuel consumption you will need to know how much power it produces at the rev required to push the boat at 10-12 mph.

    DD Fuel curves are or were plentiful on the net so if you can extract this info it should be reasonably easy to see if he is within the ball park of the numbers he has quoted you.

    As to the navigability on rivers, I will leave it to those with more experience in these matters to comment.
  3. Laurence

    Laurence Senior Member

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    Single Engine

    When it was converted from twin engines to single engine, what was done with the rudders? I would think it would need a large single rudder behind the prop. The Roamers are generally short on rudder area and without direct prop waterflow, I think it would be difficult to handle. I think 4 gpm would be a stretch.
  4. K1W1

    K1W1 Senior Member

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    Hi,

    I think you might have made a typo there. In Post 1 it was stated that the claimed range was 1000 miles on 250 Gals.

    This works out according to my maths as 4 Miles per gallon not 4 Gallons per mile.

    The rudder arrgt is an interesting question. I look forward to reading the answer.
  5. Ray Powell

    Ray Powell New Member

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    Re-Power CCRoamer W/GM6V53

    Typo error--owner stated he thaught it would do 4 MPG.
    I did not measure the rudder but thinking back it seemed to about 16 to 20 inches sq. A swim deck of about 3 feet was added.
    Nothing about mechancial flow metering.
  6. fantasymaker

    fantasymaker New Member

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    WOW that seems extremely good. Is this something he is saying he HAS done or something he hopes it should do? Is he ready to warranty it?
  7. Ray Powell

    Ray Powell New Member

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    Owner had it in the water for trial run. Probably not very far. I'm going to see it again in a week. I'm on this site learning what I should know before purchasing something like this.
  8. Laurence

    Laurence Senior Member

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    Single diesel

    Hey Ray, how about a follow up. How did all this work out with a single diesel roamer conversion?
  9. Capt J

    Capt J Senior Member

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    The owner is stating that it burns 2.5 gph at 10mph. Look up a fuel curve chart on the 6v53. I am not familiar with their burn rate, BUT I would bet that at 1,000 rpms that engine is probably burning about 2.5 gph. NOW, whether or not 1,000 rpms will push the boat 10 mph, is something that needs to be tested.........Depending on the hull configeration, I wouldn't think that a 36' boat would have a displacement speed of 10mph, but I may be wrong.

    As long as the boat has a properly sized rudder, I don't think that navigating rivers should be a problem........docking may take a little practice.
  10. Laurence

    Laurence Senior Member

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    I still think steering will be an issue but a sea trial should answer that.

    Attached Files:

  11. K1W1

    K1W1 Senior Member

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    Hi,

    Is this single engined Roamer having a prop on one side or one in the middle?
  12. Capt J

    Capt J Senior Member

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    If the single propeller came out in the center of the boat, and they installed a rudder behind it in a typical single engine installation and removed the 2 rudders, why would steering be an issue? Rudders don't even have to be directly behind the propellor, if they are large enough, to be effective.

    I worked on a 97' long range canoe stern motor yacht, similar in style to an older Feadship. It had twin engines and propellers, yet had a large single rudder in the center of the stern, the boat had no bow thruster and it steered very well.
  13. gravy

    gravy Member

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    single engine

    Single engine with twin shafts and trans ? Is that possible! Think about it
  14. K1W1

    K1W1 Senior Member

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    Hi,

    I do not think that this is what this thread is discussing.

    But it appears that this can be done: http://www.boattest.com/resources/view_news.aspx?newsid=3230

    Two engines can also drive a single prop shaft.