Performance curves BBC

Discussion in 'Gas Engines' started by TollyWally, Jan 5, 2008.

  1. TollyWally
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    TollyWally Senior Member

    I am trying to get my hands on some performance curves for a 7.4 (454) marinized by Volvo. Specifically Engine # BB740 A SW 410012601586817
    8:1 compression. Thanks for any clues
     
  2. jsh
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    jsh Junior Member

    I will email to you performance curves for a crusader 454. Should be close enough. let me know
    john
     
  3. TollyWally
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    TollyWally Senior Member

    John,
    That would be absolutely wonderful, I greatly appreciate that.

    Thanks
     
  4. No Joe
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    No Joe Freshwater Fred

    454, 320 or 350 hp

    I'd like a set too.
    Mine are 350hp (on the valve cover) w/ Q-jet, but I keep hearing 320hp. Whats the difference?
    I know on the 318 Chrysler the difference between 195 & the 225 hp was a 4 barrel carb.
    Fred
     
  5. TollyWally
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    TollyWally Senior Member

    Hey Joe,
    I have that data on another hard drive that is currently not hooked up. This is a super place to get motor info. They are drag boat guys and some of them are extremely knowledgable.

    http://www.performanceboats.com/html/forums/

    Generally speaking many of these 454 motors are quite similar in real horsepower despite advertising claims. The drag boat guys concencus is a 320 hp motor might make 280 on a good day. Look at your compression ratio for clues.

    I will try to get those curves for you but it will take a while. Meantime why not put all the specs of your motor up.
     
  6. jsh
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    jsh Junior Member

    hey joe I posted the curves on the other thread you posted on recently (prop size) in the inboard section
    its on page 1 as a .pdf attachment
    john
     
  7. powerabout
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    powerabout Senior Member

    I watched a Mercruiser 330 ( 454 ci) on a dyno in Australia years ago.
    It made 260+ horsepower and 330 ftlbs ....mercury dispute this.
    A 370 ( high performance 454) made 300+ and 370ftlb
    A 260 ( 350cu) made 220+ and 260ftlb
    (These were all with dry headers not the marine manifolds/risers from the engines)

    I also know a 260 and the old 225hp outboard pumped the same pressure on land & sea dyno...

    As mentioned above the v8's have very low compression so are not as potent as you think
     
  8. jsh
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    jsh Junior Member

    bbc engine curves

    this type of comment does nothing to further anyone's knowledge. if you have run a 7.4l on a dyno post the results. it is unacceptable to claim a contrary posistion without providing data that is at least as precise as the data you are challenging.
    I'm just saying accuracy is important that's all
    john
     
  9. powerabout
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    powerabout Senior Member

    I thought I was agreeing with Tolly?
    It was 20 years ago so sorry I dont have the sheets
    Where was the precise data I am challenging?
    I would guess Land & Sea might still have the data for production engines.
    But I think they just listed max dyno pressure if my memory serves me?
     

  10. jsh
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    jsh Junior Member

    here are performance numbers published by manufacturer. I posted some time ago to further a different discussion.
    john
     

    Attached Files:

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