I need a manual on tuning dual quads
- Thread starter duster360
- Start date
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dodge freak
Well-Known Member
Well since most went to a single carb by 1970 it can be hard to find.
How I tuned mine was to set the carbs up to 500 cfm Edlebrock dual carb specs. The primaries were close to the single carb spec but the secondaries were quite a bit leaner, like .015 smaller jets in back.
Both carbs I have adjusted the same. Both are open about the same amount for idle and I found 1 to 1 linkage work the best for it. Progressive was too mussy at first and then came on too strong, with 1 to 1 the power comes on more evenly. Now before I got a 10 inch 3,000 stall converter having the linkage 1 to 1 shifted too hard - like barking the tires part throttle around town, not cool when it happed too often
Don't be intimidated, its not very hard, just time commissioning to have to remove 2 tops off the carbs and changing 4 secondary jets vs 2. Better to be too rich then too lean.
First thing is set the timing so its all in by 3,500, around 32 degrees and once jetted pretty close then you can try 34 - 35 degrees depending on fuel octane
How I tuned mine was to set the carbs up to 500 cfm Edlebrock dual carb specs. The primaries were close to the single carb spec but the secondaries were quite a bit leaner, like .015 smaller jets in back.
Both carbs I have adjusted the same. Both are open about the same amount for idle and I found 1 to 1 linkage work the best for it. Progressive was too mussy at first and then came on too strong, with 1 to 1 the power comes on more evenly. Now before I got a 10 inch 3,000 stall converter having the linkage 1 to 1 shifted too hard - like barking the tires part throttle around town, not cool when it happed too often
Don't be intimidated, its not very hard, just time commissioning to have to remove 2 tops off the carbs and changing 4 secondary jets vs 2. Better to be too rich then too lean.
First thing is set the timing so its all in by 3,500, around 32 degrees and once jetted pretty close then you can try 34 - 35 degrees depending on fuel octane
70Duster440
Well-Known Member
I called Edelbrock to see what they might suggest. Here is what they suggested for a baseline:
Primaries: 68 x 47 rods
Secondaries: #77 jets
Dodgefreak, does this look anywhere close to where you ended up?
Primaries: 68 x 47 rods
Secondaries: #77 jets
Dodgefreak, does this look anywhere close to where you ended up?
dodge freak
Well-Known Member
Yes, I started off with .077 secondary and now its .080
The rods I know but forgot the jet size. But my rods are old Carters, the same as Edel but the new rods aren't offer in as many sizes.
72 x 52 and for cold temps 70 x 52
Timing needs to be at 32 - 34 all in - no vacuum, 20 at idle is idea but you need to mod the dist or buy an MSD dist, I got an E curve - you turn switches to control the timing curve
The rods I know but forgot the jet size. But my rods are old Carters, the same as Edel but the new rods aren't offer in as many sizes.
72 x 52 and for cold temps 70 x 52
Timing needs to be at 32 - 34 all in - no vacuum, 20 at idle is idea but you need to mod the dist or buy an MSD dist, I got an E curve - you turn switches to control the timing curve
dodge freak
Well-Known Member
I removed the front carb secondary air door and lighten the weights for the rear carb door. Removing both air doors work great expect on the street I missed just leaving it in 3rd at 60 and punching it, carbs wanted second gear but wasn't cool scream it often times so back in the rear air door went for better pick up without hitting 6,000 or more
Thanks for sharing. Any updates?
Looking at dialing in 2 Eddys(1405/1406) on Offy sb DQ.
Thanks
Looking at dialing in 2 Eddys(1405/1406) on Offy sb DQ.
Thanks
67Dart273
Well-Known Member
But on WHAT? I would think lightening/ removing air doors would really cause a serious bog on smaller engines.
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