Step up spring clarification?

Discussion in 'Fuel and Air Systems' started by DesertRat, Oct 31, 2018.

  1. DesertRat

    DesertRat FABO Gold Member FABO Gold Member

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    I am getting ready to install the new rods and springs in my AVS2. I have the complete eddy spring set and my research shows to pick the spring that is rated at 1/2 of your vacuum at hot idle in drive for an automatic. Does this sound correct? Thanks for the help in advance!
     
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    • toolmanmike

      toolmanmike FABO Staff Staff Member FABO Gold Member

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      It should tell in the instructions or may be download from Edelbrock's website. I just printed off the tune directions for my 1406's. I have glanced through the instructions but haven't studied. I did see a chart where it carb adjustments are in the center and it tells you what direction to go if you need rich or lean. It seems to be a bit confusing if you are just adjusting by the seat of the pants.
       
    • DesertRat

      DesertRat FABO Gold Member FABO Gold Member

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      Thanks Mike: I talked to the Eddy tech line and the AVS2 tunes completely differently from the 1406. The tech I talked to recommended the rods I got and I bought the spring kit which has them all for $10 so its a no loose deal. They are working on the tuning charts for the AVS2 but they are not complete. I will just read my hot vacuum in park and go with the spring calling for that "of HG to start.
       
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      • Hellrats

        Hellrats Still wrenching after all these years FABO Gold Member

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        Bookmarking this one :) I've put on three AVS2 Carbs this year (2 on friends cars) and so far they have been great right out of the box. I put the 650 on my car but the weather has turned to shit so not much playing around with it. I'll put the A/F gauge on it in the spring. Was yours lean or rich and at what circuit? Also what is your altitude?
         
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        • DesertRat

          DesertRat FABO Gold Member FABO Gold Member

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          I started with a wideband on mine so it was easy to see. It is running fine at hot idle but rich at cruise, about 12.5+-. I want it to cruise about 13.5+- so it is a small adjustment. The tech wanted me to leave it alone but he isn't buying my gas so he reluctantly recommend the rod change that I bought and the spring kit was a no brainer. I will keep the thread posted.
          Edit: The tech said to read the plugs, it was more important and my plugs read perfectly the way the carb is now.
           
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          • Hellrats

            Hellrats Still wrenching after all these years FABO Gold Member

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            I knew something was different in them other than the boosters but being brand new I wasn't going to dissect them. Oh and your are correct they did not come with the chart the other carbs come with. My thinking is the air bleed holes or routing is changed so the jets and rods are going to be different.
             
          • Hellrats

            Hellrats Still wrenching after all these years FABO Gold Member

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            Cool. A little fat might not be to bad this time of year. But yea, a rod and spring change is nothing to do. Keep us updated and thanks :)
             
          • toolmanmike

            toolmanmike FABO Staff Staff Member FABO Gold Member

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            I think a wideband is the way to go. A little fatter rod on the little end. Doesn't sound like it's that far off. As long as it doesn't ping. Have you noticed a difference in how it runs or sounds?
             
          • DesertRat

            DesertRat FABO Gold Member FABO Gold Member

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            I just got my valvetrain sorted and checked my vacuum. I have 12" hot in park and 10" in drive. Will probably change the rods first without a spring change and go from there.
             
          • 69_340_GTS

            69_340_GTS Well-Known Member

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            That's what Edelbrock told me. But it did not work. First of all, good luck figuring out which spring is which in that kit. The color-coding really sucks, and doesn't really jive with the chart they supply. I'm just doing trial & error now. Damn thing still has a big "bog" when you stomp on it.
             
          • DesertRat

            DesertRat FABO Gold Member FABO Gold Member

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            I changed the rods and springs. I should have only changed the rods, putting stock springs back in in the morning. I redid my valve cover gaskets as I had a weep and tested the car. It idles at 14.6+- and cruises at 14,2/3 jumping around a bit. It is running 5 degrees hotter than is was so it's definitely leaner. I will test and report after putting original springs but leaving the fatter rod to see if that helps. With this weather I may just put the original stuff back in, winter likes a little more fuel. More later-------------------
             
          • DesertRat

            DesertRat FABO Gold Member FABO Gold Member

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            So the verdict is in. The stock rods that were in my AVS2 from the vendor were 70 X 52 and the change recommended by Edelbrock was to change to 73 X 52 which I did. I left the springs that came with the carburetor and my wideband shows 14.6 at idle and 13.5-14 at light cruise which was my target. I am not changing anything else on the car now. I think the as-shipped rod/spring combo would be fine for more CI but my little 273 didn't need that much fuel. I'm moving on to my 40 ford pickup/Y-block build which I can't post about here.
             
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