New Holley tuning challenge, setting up another Purple monster lol

Discussion in 'High Performance Modifications' started by G72Zed, Aug 6, 2020.

  1. G72Zed

    G72Zed Veteran Member

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    Well, don’t know what it is, but I seem to get these purple “Barney” engines coming in for work. At least this is a C7 Chrysler Hemi, but it’s a monster, how I miss the simplicity of tuning tunnel rams lol.

    This thing is fussy!!! Anyone out there with experience on tuning cross rams like on the old 67-69 Z28’s ? Any common trends that Could be used as a rough guide like Idle circuits and jetting trend,

    I know it’s a long shot, just trying to get some info, never did a Z/28
    CrossRam so no references in my tool box.

    Thanks




    48673B8B-C69F-4E4C-9686-4C192B494038.jpeg
     
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  2. Jodi

    Jodi Veteran Member

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    I got nothing but trial and error :rolleyes:... you probably forgotten more than I'll ever know when it comes to tuning dual carb set up LOL.
    BTW that is a very nice looking engine. I always appreciate MOPARS.
     
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  3. Twisted_Metal

    Twisted_Metal Administrator Staff Member Lifetime Gold Member

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    Reminds me of the "Crossfire" setup in third gen Camaros. But they used throttle bodies, and didn't work well.
    My only experience with those was unbolting one from an engine and swapping it for a Q-Jet intake and carb.
    So... No help here.

    With your vast experience with everything else, I'm sure you will figure it out.

    Good luck with "Barney".
     
  4. 1320feet

    1320feet Veteran Member

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    You'll have fun with that. Are those 1850's? Is it street driven or a track only car? If its a street car. I'd reduce plenum volume with some a+b puddy.
     
    Last edited: Aug 8, 2020
  5. 1980RS

    1980RS Veteran Member

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    Ah the Hemi Cross ram setup. Have you done the dams inside the intake yet? if not I guess it's supposed to help a lot.
     
  6. muscl car

    muscl car Veteran Member Lifetime Gold Member

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    That pic of that Hemi Cross ram reminds me of someone I know who has a 65 Plymouth Savoy with a 426 Hemi running a cross ram
     
  7. G72Zed

    G72Zed Veteran Member

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    Well, got the purple "Barney" Hemi somewhat done and running well, but unfortunately there are a few issues with the engine, so it will be coming out to be assessed and gone through. Next R&D tuning session will be on the dyno once it's gone through, so that will be better anyway.

    To answer a few of the questions, the Holley's are of the original design and part numbers as per the old/current SS rules, I am not sure on this. Both are the 770 cfm per 1965-69 OEM. Intake is full of AB, wings done,corners filled and more, all done up.

    This is a street cruiser, the owner bought the engine to go to "Cars and Coffee" he did not realize a 572ci, with approx. 700+HP (estimated) Cross ram Hemi will be a little fussy to drive LOL. I was at the dyno and there was a 572 Hemi, but it ran 116 octane and was using the dual 770's on the Xram, ran well, made almost 1,000 HP, single dominators were tested, loss about 35-45 HP, so not that bad. But when you start the test at 5,300 RPM, not to worried about street manners and drive-ability anyway (to a point).

    Ah well, live and learn.
     
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  8. biker

    biker Veteran Member

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    Good lord. That whole thing sounds like dollars upon dollars.
     
  9. G72Zed

    G72Zed Veteran Member

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    Yes, you are right on the money biker, and by that I mean 6 figures on the money.

    I could only drive the car back on the trailer, not pleasant informing the customer that it's not only far from being road worthy, but not safe to drive.

    I felt bad for him, but he was happy I went through it, at least it runs now.
     
  10. CorkyE

    CorkyE Veteran Member Lifetime Gold Member

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    Think I missed something here. Just asking, but why is it not road worthy and not safe to drive? Is this something unrelated to the tuning you've done?
     

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