33 footer??

Discussion in 'Powerboats' started by Bryan1978, Jan 20, 2009.

  1. JohnnyO
    Joined: May 2008
    Posts: 7
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    Location: Lake Arthur, Louisiana

    JohnnyO Junior Member

    Also - the hull I have is 33ft x 12ft....

    You said you don't like outboards... but you mention that $$ is an issue... sounds like you and me have similar situations in regards to our wallet density....

    With the $$ you save on "construction" of a hull.... You could easily equip the boat with 200hp twin diesels instead of the gas engines for even more economy....

    FYI - here are my calculations with twin 150hp outboards... Notice fuel burn and speeds... Those 350 mercruisers are going to burn equally the same amount of fuel... The outboards are lighter, therefore making them more efficient..... at cruise you're getting 2.9mpg at WOT you're getting 1.8mpg.... That is VERY efficient consider the size of the boat you're wanting and the speeds achieved..... These calcs were done using "average planing type hull, 10,000lbs displacement.

    MAX PERFORMANCE
    Available Power: 285.0 SAE hp ( 212.5 kW) @ 5500 RPM
    Max Speed: 28.4 kts :p
    Fuel: 18 US Gall/Hr (typical)
    CRUISING PERFORMANCE
    Cruising Power: 142 SAE hp ( 105.9 kW) @ 4250 RPM
    Cruising Speed: 20.0 kts
    Fuel: 8 US Gall/Hr (typical)

    JohnnyO
     
  2. JohnnyO
    Joined: May 2008
    Posts: 7
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Lake Arthur, Louisiana

    JohnnyO Junior Member

    Sorry - I did not read this response... Here are the calculations again with the 350HP Mags you have with your configuration.

    MAX PERFORMANCE
    Available Power: 570.0 SAE hp ( 425.0 kW) @ 5500 RPM
    Max Speed: 37.0 kts
    Fuel: 35 US Gall/Hr (typical)
    CRUISING PERFORMANCE
    Cruising Power: 284 SAE hp ( 211.9 kW) @ 4250 RPM
    Cruising Speed: 26.1 kts
    Fuel: 17 US Gall/Hr (typical)



    I agree, you may be in a little over your head with building out your 1st boat , I started about 10yrs ago with Perogue and Canoe designs. Anything larger I always buy a stripped out hull and customize it to my needs.

    Your could fly with those twin 350mags with a 33ft boat.... but keep in mind... the faster you go - the more fuel you burn ! :D
     
  3. Bryan1978
    Joined: Jan 2009
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    Location: Tampa fla

    Bryan1978 Junior Member

    well the money is an issue basically, I have twin 350 mags, I cant get the money out of them selling used, outboards are better off new in my opinion so theres the problem, twin 175's will run almost 20K apiece. Why buy something when you got good motors already, I want to build a boat around the power I got. I'd love to build something that can go far and fast, fuel burn rate isnt going to kill me till gas starts hitting 4 or even 5 bucks a gallon, then its less trips.

    Can you get some pics of this hull, I might be interested if it looks doable. I'll call later sometime. Thanks for the info.

    Bryan
     
  4. JohnnyO
    Joined: May 2008
    Posts: 7
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    Location: Lake Arthur, Louisiana

    JohnnyO Junior Member

    Hey Brian - I don't have your email... Please post your email and a # for me to call you at. I'll send you some pictures. It's in Bradenton so you could actually go and take a look at it in person. The guy I bought it from worked for a boat company for 30yrs and is very knowledgable.

    I agree - if you've got good motors and all the hardware, then go that route. The $$ you save on power options with what you have already it just doesn't make sense to spend more to save on fuel... you will never see the justifications in $$ amounts.

    I have twin Chrysler 318s V8s (225hp) motors that I was going to put in it.

    Just load yourself up with 200gallons of fuel and head for the shoal drop-offs !

    FYI - Im very familiar with the gulf.... why do you think you've got to travel so far out of Tampa to get to deep water ?

    JohnnyO
    337.368.7188
     
  5. Bryan1978
    Joined: Jan 2009
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    Location: Tampa fla

    Bryan1978 Junior Member

    I know right, out here water drops 10 feet for 10 miles, want to hit 100 feet, go almost 100 miles. I've thought bout the east coast, dove out of jupiter several times, 120 feet like 100 yards off the beach, its insane but almost all fished out due to it being to easy for people to get out.

    E-mail is gagt1978@gmail.com, e-mail me and I'll get you my number.
     

  6. marshmat
    Joined: Apr 2005
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    Location: Ontario

    marshmat Senior Member

    Hi Bryan,

    I'll second the advice on tracking down Dave Gerr's book "Elements of Boat Strength". It's about $35 and worth its weight in (pick the precious metal of your choice).

    If you have engines that work, you may as well use 'em. The Bravo 1 should be able to handle the torque of a 350 V8 for many, many hours; most stories I hear about Bravos self-destructing tend to involve a supercharged 8.1 or something ridiculous like that.
     
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