Hello From WI

[71GSSDemon]

Hello, my name is Eric. I have a few cars I play around with. I joined from a bunch of great information I have read on here. One project I am working on that I need help...


Holley 4224 660cfm center squirters. 1:1 linkage for both carbs and secondarys. 50cc accelerator pumps, center squirter to all 4 barrels

Any help is greatly appreciated. I have a question or many. My combo is below. It idles great, starts great and if going moderately to WOT, it accelerates awesome. But, if stab to WOT, it has a bad stumble then recovers. I adjusted the accelerator pump cam to #2 hole to see if that helps and it did, some. Also the cams were upside down riding on the near vertical ramp instead of the gradual ramp. Also, with no load, stab to WOT is great but slowly increasing throttle it misses badly about 2700-3000. I can watch in the throat of the carbs and the fuel doesn't seem to be atomizing well from the booster on the rear carb and the front is doing nothing while this is happening, but comes in shortly after and does the same thing. The fuel is acting erratically during this time (too much emulsion?) This happens both in park and while driving. I think it is a bad spot between transfer slots and jets??? Moderate throttle is good here. So, light throttle acceleration (in park or while driving) at 2700-3000 is an issue, passed that it works. And the sudden stab to WOT is an bad stumble but recovers. In Park, it revs freely so it tells me that I need a longer accelerator shot, maybe. I think of this a comparison of light car (park) and a heavy car (load on engine while driving). I did try running one accelerator cam one way and the other carb cam the opposite in thoughts to have a big shot of fuel, and a longer shot to help carry it. No modifications have been done to the carbs. #76 jets in primaries, no PV, #12 jet plates, brown 336 accelerator cams.

1971 Demon, Low compression 440 with Hughes whiplash cam (specs below), shaved and ported #250 iron heads, Weiand tunnel ram with Holley 660s, MSD pro billet ready to run distributor, 2" fenderwell headers, 2500 stall and 3.91sg and 29.5 tire.

Initial timing is 18⁰ with full in 36⁰ coming in at 2200. Vacuum advance is hooked up to manifold vacuum as there are no ported vacuum ports. Plugs looked a bit on the lean side. I was at 1 turn out in idle mixture. It is much happier at 1.5-1.75 turns out.

I got to wondering if the air is just lazy due to lack of motor and booster signal. It worked better with some small air cleaners I used to run. Maybe the restriction on the air increased the booster signal? Maybe why it works great if stopping at 3/4 throttle?