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low end bog under load (brake torque)

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  • low end bog under load (brake torque)

    Seems like I've tried everything over the past few years....3 different carbs (625,650, and 750), different intakes, metering rod swaps, step up spring swaps, bigger squirters, etc, etc. I just can't seem to find the right combination to get any low end torque. If i stand on the brakes, the motor bogs down, but still runs, but tires barely break loose most of the time. if they do break loose, it does an awesome burnout! Even if I am not attempting a burnout, but just launching, it doesn't really get going until the midrange powerband. Mid range and high end power are great! Timing is set at 22 initial, 38 total, all in at 2400, I have a '66 belvedere with a 360, mid range cam, edelbrock performer rpm intake, msd ignition and distributor (no vacuum advance), dougs headers, flowmaster exhaust, 727 auto with 2600 stall (changed form 2000 stall), 355 gear with sure grip. currently running the 750 carb, but still had the torque issue with 650 and 625, and had less mid range and high end power.

  • #2
    here are my cam specs....


    • #3


      • #4
        Man that's a lot of timing. My small blocks are usually set for 12 initial and 32-34 total for 93 octane.

        I know you've tried a lot of CFM sizes and spring/rod changes (are the carbs Edelbrock Performers?) but it sort f sounds like too much gas on initial hit. I once had an issue like this that was caused by a screwed up dīstributor that had timing all over - but it would alse nose over at high RPMs. Have you verified your fuel pump gives good pressure quickly?
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        • #5

          So i would put a lighter spring/springs in the dizzy to have all advance in by 1500. if that don't work you have the cam in retarted . That happens so often. with the tightish converter I would install it at 104 (calls for 106) i suspect it may be in at 110 or farther back and that makes them flat as piss on a platter till the rpms come up.
          Last edited by dodgeboy8; 04-09-2018, 04:32 PM.


          • #6
            Was the cam degree'd when installed?
            It should have been installed with 4 degrees advance.
            It's a fairly heavy car with a small block engine - you want more bottom end grunt.
            The initial timing at 22 degrees is fine - a couple of 340's in my area run at 20 degrees initial with no issues.
            Plus you have some converter and gear which helps.
            You didn't mention what heads are on the engine along with valve sizes.
            If you are running fuel with ethanol in it - stop running it.