Edelbrock springs 1406 and 1405

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Yes, fishin and grandbabies need to always take priority. Good for you!
 
Ok so went for an approx 10 mile drive. Surging is more pronounced/frequent and couple good backfires thru the exhaust.
18* initial
650 rpm and 14" vac(in park, idling)
475 rpm and 11" vac(in gear, idling)
Idle mix screws approx 1 1/4 turns out.
Orange 5" stock springs
Suggestions?
An O2 sensor or A/F meter isnt in the budget right now. I've got a little more than a week before Moparfest.
Thanks
Steve
 
Just pulled(and broke lol) plugs. Similar to before, plugs get worse front to back.
Close up pics are cyl 1,3,5,7

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20230806_210644.jpg
 
Hate to be the bearer of bad news, but I doubt this combo will ever run properly. Too much carburetion & not enough cubes.

I would try this if it was mine:
- progressive linkage so that first 1/3 of throttle movement engine runs on the primaries of the rear carb; final 2/3 of throttle movement, all 8 barrels get to full opening at WOT.
- front carb: remove piston springs so that rods drop down. Find some wire [ a piece of stranded copper wire ] that is the size of the idle feed tube. Should be 0.031" to 0.036" range. Poke about 1/4" inside the IFR, bend the rest over & soft solder to the IFR tube [ to keep wire in place ]. Do both IFRs. [ Can be removed at any time ]. Screw mixture screws all the way in until seated. [ Idea is to ensure idling & low speed cruise is all done by rear carb ]. Close the pri t/blades until they are fully closed, but not binding in the bores.
- with front carb contributing less idle air, idle speed may be too low. So bypass air needed. Drill a small hole in the secondary [ not primary ] blades of the front carb. This is to distribute air more evenly.
 
Thanks, I'm wondering the same thing, that it may be better suited for more cubes/compression.
Bewy said:
Hate to be the bearer of bad news, but I doubt this combo will ever run properly. Too much carburetion & not enough cubes.

I would try this if it was mine:
- progressive linkage so that first 1/3 of throttle movement engine runs on the primaries of the rear carb; final 2/3 of throttle movement, all 8 barrels get to full opening at WOT.
- front carb: remove piston springs so that rods drop down. Find some wire [ a piece of stranded copper wire ] that is the size of the idle feed tube. Should be 0.031" to 0.036" range. Poke about 1/4" inside the IFR, bend the rest over & soft solder to the IFR tube [ to keep wire in place ]. Do both IFRs. [ Can be removed at any time ]. Screw mixture screws all the way in until seated. [ Idea is to ensure idling & low speed cruise is all done by rear carb ]. Close the pri t/blades until they are fully closed, but not binding in the bores.
- with front carb contributing less idle air, idle speed may be too low. So bypass air needed. Drill a small hole in the secondary [ not primary ] blades of the front carb. This is to distribute air more evenly.
Click to expand...
 
Heres compression test results. Initially I thought low, but they're well within fsm spec. Both carbs wired open, all plugs removed.

20230807_125829.jpg
 
Do you have access to a single carb manifold? If you're going to be doing some miles, it may be better to narrow it down to one carb (you can try each to see which one runs better).
 
Thanks, yes I'm gonna put single 4bl back on. I'll set the DQ aside for another build(hopefully)
Aaron65 said:
Do you have access to a single carb manifold? If you're going to be doing some miles, it may be better to narrow it down to one carb (you can try each to see which one runs better).
Click to expand...
 
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