Jetting for 750 DP on a Stroker 408?

Fuel and Air Systems

  1. 70DusterBob

    70DusterBob Well-Known Member

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    I know the jetting is dependent upon a lot of factors, but I am just now putting this engine together and was wondering what a good starting point would be for both primary and secondary jets.

    Thanks
     
  2. 1969383S

    1969383S FABO Gold Member FABO Gold Member

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    Stupid answer but here goes.

    Fresh out the box 750 DP based on CFM sizing of the build! That is where I would start.
     
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    • Garys72Duster

      Garys72Duster Well-Known Member

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      I would start with stock jetting. Then read the plugs, and possibly go a little richer if need be. I really doubt that you would need to go any leaner, since you are in Texas.
       
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      • AJ/FormS

        AJ/FormS 68 B'cuda fb, Form S clone ... 367/A833/3.55s

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        By way of comparison;
        I think my 367Streeter runs 74/82 , and went 93 in the Eighth on that. The math says 433hp IIRC. I think it's a tad fat, but I've been running that since 2004, and still on the same plugs,lol.
         
      • 70DusterBob

        70DusterBob Well-Known Member

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      • AJ/FormS

        AJ/FormS 68 B'cuda fb, Form S clone ... 367/A833/3.55s

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        She looks like a real sweetheart
         
      • 70DusterBob

        70DusterBob Well-Known Member

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        Thanks AJ, I will put a pic of it in the little window to the right when it's done and post a pic too.
         
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        • KnuckleDuster

          KnuckleDuster Well-Known Member

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          Old thread revival, but....

          Where in Texas are you? I'm in Georgetown.
          What did you end up with for jetting?
          Just curious, I'm playing with jets in mine. Right now I'm running 70/88 in a 750cfm Proform double pumper on a 410ci with a one inch spacer on an air gap. My 410 is almost part for part the Blueprint crate, but built before they started. Same heads (though ported now) crank, cam, very similar pistons and same 10.1:1 scr.
          Been going up on secondaries, since I added the spacer it was leaning out at WOT.
          Puts my AFR @ about 13.8 cruise and 12.5 WOT and running like a raped ape. Still a lean spot during transition to WOT that I need to work on, but getting there.
           
          Last edited: Mar 25, 2019
        • GMachineDartGT

          GMachineDartGT Senior Member

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          Start with out of the box. Then put a wideband meter on it. This will save a lot of time and guesswork. Get the timing right first.
           
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          • Mattax

            Mattax Just the facts, ma'am FABO Gold Member

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            Yup. Its not the 'rating' that's important for the jetting, its the actual booster type and venturi sizes as well as the air bleeds, 'emulsion' holes and so forth. So start with what the carb manufacture provided since it should be ballpark if they have any clue as to what they are doing.
             
          • 70DusterBob

            70DusterBob Well-Known Member

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            South Central, next to SA. That puts me about 300 miles south of you.

            I haven't gotten it running yet. It runs, but I mean running. It needs exhaust, and a professional job at that. Someone in here recommended Flanagan's Muffler Shop. He is in Marble Falls. I plan on getting it there this week. I will let you know what I end up going with, but I will need you to reply again to remind me, memory ain't what it used to be. lol

            I have 74/84's in there now if I remember right, and it isn't running very rich, just a tad at cruise and idle. Still in my break in period, and I havne't driven it much since I got it put together due to financial woes. Soon it will be up and running though... I'm hoping for next week. I went one step up on the bleeds, brought it into the slightly rich side. Just a tad. There is no in between I don't think, between the stock and one step up in the bleed kit.

            Thanks
             
          • 70DusterBob

            70DusterBob Well-Known Member

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            I did get a AFR gauge put in. So yeah, that will take out the guess work. Thanks
             
          • KnuckleDuster

            KnuckleDuster Well-Known Member

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            I'm gonna pm you a number to a guy I used for my 72. If he is still doing exhaust, you should call him. He is an old drag racer , now in his 80's,and he "retires" every summer when it gets too hot. He does nice work, though, and it won't cost you $1000! I need to go see him myself if he is up to it, for my new 71 Duster.
             
            Last edited: Mar 31, 2019
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