74 ranchero refresh

Discussion in 'General Ranchero Help' started by Dan the ranchero man, Dec 20, 2018.

  1. colnago

    colnago In Overdrive

    Messages:
    678
    Location:
    Ridgecrest, CA
    The problem with carbs is that people usually go too big. The typical rule is:

    CI x RPM x VE / 3456 = carb size

    Sounds like you went from 750 CFM to 600. I think I'm gonna need something in the 350 - 500 CFM range for my 289.

    By the way, 97* high in SoCal today. It's gonna be a warm one ...

    Joseph
     
  2. Dan the ranchero man

    Dan the ranchero man MODERATOR Staff Member

    Messages:
    3,918
    Location:
    Mchenry , IL
    You are right about the carb sizing. Most guys go way to large. I used the carb calculator on the summit website. The most important thing when figuring out what size you need is being honest to yourself on the max RPM you will be using you engine. Everyone thinks they are running the 1/4 mile in a 2000 HP car@ 10,000 RPM. When they are really running 300 HP @ 4000 RPM. This is the third 460 that i have put a 600 CFM carb on it and it runs absolutely great. two where my own and the other was a friend who insisted he needed a 950 double pumper. the 950 just never ran like he thought it should. So he gave in a we put a stock used 600 on his 460 and the thing ran like a new car! that was over 25 years ago and that is when I saw for myself that bigger was not always better. The 750 vacuum secondary ran OK but I knew it was still to big for my application. Money was tight at the time and I bought the 750 for $75 from another friend with the intention of changing at a later date (in this case 18 years later).
     
    colnago likes this.
  3. colnago

    colnago In Overdrive

    Messages:
    678
    Location:
    Ridgecrest, CA
    "Honest to yourself." I like that. To me, it encompasses so much about the engines we're wrenching. If you're really going to use that monster on the strip, more power to you. If you're going to use that monster to make grocery runs, well ...

    Joseph
     
  4. handy_andy_cv64

    handy_andy_cv64 In Maximum Overdrive SILVER MEMBER

    Messages:
    8,857
    Location:
    Everett, WA
    Running a bigger carb is like running a richer engine--people are set in their beliefs it makes more power, like a silver bullet, when it just does not. But, you can't tell them that.
     
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