Dual quads versus big hammer!!!...

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yellow rose said:
Looks a skosh rich at cruise, but you saw that on the gauge. It's hard to tell from the picture, but watch the center wire very close as you get the tune up closer. You should see some erosion of the edges of the center wire and the edges of the ground wire. That's when you are really close.

You are definitely making progress. I'll take tenacity over cookie cutter any day.
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One of my biggest problems is the limit in step up rods and also in jets for the primary. 74's are the leanest primary Jets and I have them in.. Then the rods I believe there's 11 different options.. and I believe about three-quarters of those are equaling steps as in you can't have a 62 hi sep with a 44 low step. Like on Edelbrock you can get I think like a 75-37... And every imaginable number in between...
And right now on the secondaries I still don't know if the doors are not opening all the way is my problem(not enough air) or I just need to jet down... When I'm driving about 45 to 50 and slam it into 3rd gear and punch it and watch the af gauge it's at about 11.5... I'd like to see 12.3-12.5...
When cruising along at 50mph or so I'm seeing hi 12's on the AF gauge. I can just very slightly open a little bit more and see a consistent 13.4-13.6... but when I go back to steady hi-12's.. when I give it gas a little slower it has a little bit of a soft spot and goes very well that the AF gauge goes pretty damn high 16-17.. then falls back down to 12 or 11 and steadys back out at high 12... When I downshift and hold down hard that's when I see the low 11s kind of steady...
Letting off the gas coming to a stop for a stop light relatively easily it goes extremely lean 18-19 and almost kind of wants to die but doesn't never...
I tried to just drive it and cruise it along and it does great and there's no surging, but you know I'm expecting EFI kind of driving LOL.. it's not unpleasant as it may sound but still I'm looking for the best tune I can..
 
It was a cheap carb shoot out.
They didn't like the fact, that you well know, that the carb has to come off for a jet change.
they tested the summit 750 carb your demon carb, and a AFB. all were 750cfm carbs
Believe it or not the Summit carb one on ease of jetting(all though it ran perfect out of the box and they didn't touch it.
And make the most power.
this carb
Summit Racing® M2008 Series Carburetors SUM-M08750VS
 
Its motor tread on demand.
It only like 3 buck a mouth of something like that. tones a grate hot rod shows that are on tv and lots that were -tubes like Roadkill.
Its dirt cheap, i just when and did it.
 
Cudafever said:
Its motor tread on demand.
It only like 3 buck a mouth of something like that. tones a grate hot rod shows that are on tv and lots that were -tubes like Roadkill.
Its dirt cheap, i just when and did it.
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Really the trick on the carb is to take all 6 of the screws out of the bottom and then you just have to take the two out of the top until you get it adjusted and you just have to put them all back in. Again that's just for the jetting... Also basically once their set they're set, so there isn't a lot of tuning once they're done..
I may have to do some pioneering here as these weren't developed for a dual quad application I'm sure...
 
So the extra hole in the air door?????? worked.......not ......kinda......?
 
For a comparison I think there's maybe six or eight primary jet sizes and maybe 9 or 7 different metering rods sizes. As opposed to Edelbrock where there is 50 different Rod sizes in a wide a narrow range of steps and an unlimited amount of jetting...
I thought about making my own metering rods out of Edelbrock rods...
Right now it seems like with the smallest primary Jets when I run a rod that's fine enough for the idle I can't get it to step down far enough for the acceleration...
The small ride here in this example or show a picture of is the street demon 625 Factory road 60-52 (80jet) and the one that's taller is the Edelbrock 71-47.. Factory in a 1406 600 Edelbrock is a 75-47 (95jet)...
You can see how the Edelbrock allows a larger step and its ride for the transition...
IMG_20200322_202347.jpg
 
Cudafever said:
So the extra hole in the air door?????? worked.......not ......kinda......?
Click to expand...
I really need more time with it.. I gave it one shot the day I got them on Thursday and it was the one time when I left the air filters off and it was on the street during a bad time of day and I only got one time to kind of really open it up which I really don't like doing in town.. they didn't seem to flick open but bobbled like normal and maybe a little bit more open. But I didn't have really a lot of time to hold It wide open... I think I still have room tolighten the spring and let them open up faster and more. That's what I was saying to yr about whether they need to open up more or I need a smaller jet to make that 11.5 go up to a 12.5...
The one and only great tuning thing about these carburetors as far as different size availability is the secondaries are Holley Jets...
 
j par said:
For a comparison I think there's maybe six or eight primary jet sizes and maybe 9 or 7 different metering rods sizes. As opposed to Edelbrock where there is 50 different Rod sizes in a wide a narrow range of steps and an unlimited amount of jetting...
I thought about making my own metering rods out of Edelbrock rods...
Right now it seems like with the smallest primary Jets when I run a rod that's fine enough for the idle I can't get it to step down far enough for the acceleration...
The small ride here in this example or show a picture of is the street demon 625 Factory road 60-52 (80jet) and the one that's taller is the Edelbrock 71-47.. Factory in a 1406 600 Edelbrock is a 75-47 (95jet)...
You can see how the Edelbrock allows a larger step and its ride for the transition...
View attachment 1715492125
Click to expand...
I can see why people clip the ends of the rods off.. I'm having thoughts of cannibalizing a set that I have.. I wish I could have some kind of lathe 2 mil the bottom step down to a 34..
 
j par said:
I can see why people clip the ends of the rods off.. I'm having thoughts of cannibalizing a set that I have.. I wish I could have some kind of lathe 2 mil the bottom step down to a 34..
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we used to use a fine file on the ends of the rods on the TQ's, I'm sure that would work here too...
 
318willrun said:
nope. measure them in small jets. When they all fit the same length evenly, you good to go.
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I would almost like to try and blow the whole $14 and get a couple sets like these that are right where would I feel would be a good step size and cutting and bending them into what I think I need..?
Screenshot_20200322-215553.png
 
j par said:
I feel like I'd be part hot rodder and part jeweler LOL...
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I tuned super sixes, 318 2bbls, and TQ's just as I described 30 yrs ago. Amazing the results and crisp response when one takes the time for the small details...
 
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