454 HP calculation

Discussion in 'Engine Topic' started by Scott Martin, Dec 17, 2016.

  1. vegas1974z28

    vegas1974z28 Moderator Staff Member Lifetime Gold Member

    4,452
    29
    Jan 10, 2002
    Las Vegas,NV
    650 is way too small of a carb. I run a 1050. Used to run a 750.....went from 11.1xs right to 10.7x with a carb and header change. That was a while ago. Take it to the track, come back with the MPH and weight of the car....we'll tell you the REAL horsepower its making.... :)
     
  2. G72Zed

    G72Zed Veteran Member

    230
    2
    Sep 8, 2015
    Canada
    [QUOTE="Why do you think its falling over on the dyno at 5200 to 5400 ?[/QUOTE]

    I noticed the BSFC looks to be at 50%, but did not see any CFM data? Was there a hat on it? If the data is there, it would tell you if the cfm dropped off at the end along with the HP, would likely indicate valve float/surge.
     
  3. Scott Martin

    Scott Martin Veteran Member

    182
    1
    Feb 10, 2014
    Bham Alabama
    I have not had time to run the car at the track yet. I only have about 100 miles on the motor as of now and still have the break in oil in it. I have ran the 850 carb and now have a 1050 Q series 4150 style carb on . The motor feels really strong with the 1050 and has no hesitation when I stab the throttle . I will more than likely keep the 1050 on.
     
  4. Scott Martin

    Scott Martin Veteran Member

    182
    1
    Feb 10, 2014
    Bham Alabama
     
  5. Scott Martin

    Scott Martin Veteran Member

    182
    1
    Feb 10, 2014
    Bham Alabama
    I am not quite sure about the cfm data. I have a fuel spread sheet that shows fuel pressure , fuel flow , afr , fuel mass flow and bsfc. It has 2 sweeps , the first is with a 650 cfm and the second one that says sweep 191 is with a 850 cfm
     
  6. Scott Martin

    Scott Martin Veteran Member

    182
    1
    Feb 10, 2014
    Bham Alabama
    I have noticed on the dyno sheets that the AFR gets very rich with both the 650 and 850 carbs at about 5000 rpms. The 650 actually drops to 7.9 at 5400 and my 850 drops to 9.8 at 5500
     
  7. G72Zed

    G72Zed Veteran Member

    230
    2
    Sep 8, 2015
    Canada
    Looking at the data and graph, the 650 is better overall!!
     
  8. G72Zed

    G72Zed Veteran Member

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    Sep 8, 2015
    Canada
    Just a question, how do they, or the dyno program calculate AFR when there is no Air (cfm) data? Also, another KPI that is missing is the VE%. I'm sure other members will chime to lend there opinions. When you get into spring surge, the hp spoons over, cfm takes a dive and AFR does the same and goes rich. Also, you can tell as it sounds like yelling in a 45 gallon drum when you get into float, very noticeable, ask the dyno operator if that happened?
     
  9. Scott Martin

    Scott Martin Veteran Member

    182
    1
    Feb 10, 2014
    Bham Alabama
    Thats something thats way over my head ! I will definately ask about it going into valve float. If it is do I need to go with a different set of springs. The ones that are on it came from Brodix for a HR cam up to .650 lift
     
  10. G72Zed

    G72Zed Veteran Member

    230
    2
    Sep 8, 2015
    Canada
    I would deal directly with the rebuilder/shop that did the work/dyno testing. Hard to say, there might be something else going on other than springs that's causing this.
     

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