Question on adjusting dual quad carbs.
- Thread starter R68DartGT
- Start date
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??
4spdragtop did this a while back so I tagged him for you.
Newbomb Turk
Well-Known Member
You need a Edelbrock unisync and some kind of carb cover to make a tool to make sure the carbs are timed up correctly.
Amazon.com
And one of these:Amazon.com
You have to make the hole in the carb cover bigger and then glue the unisync to the cover.
Get the engine running and disconnect the linkage from one carb. You can’t have the two carbs hooked together by the linkage.
Get the idle speed where you want it.
Pick a carb (I usually set the front carb but either one works) and set the unisync on the carb. You’ll feel the hat get sucked down.
Read the manometer on the unisync. I usually set the gauge in the middle. There is a built in valve on the unisync that you can open and close to get the manometer centered.
Once you get a clean reading on the manometer pull it off and set it on the other carb and read the manometer.
If the readings don’t match, and unless you have the Midas touch they won’t match then adjust the second carb to read the same as the first carb.
And you do that by adjusting the curb idle screw.
It’s very difficult to get both carbs equally open or a better way to say it is get both carbs flowing the same air at idle regardless of where the curb idle screws are at.
Amazon.com
And one of these:Amazon.com
You have to make the hole in the carb cover bigger and then glue the unisync to the cover.
Get the engine running and disconnect the linkage from one carb. You can’t have the two carbs hooked together by the linkage.
Get the idle speed where you want it.
Pick a carb (I usually set the front carb but either one works) and set the unisync on the carb. You’ll feel the hat get sucked down.
Read the manometer on the unisync. I usually set the gauge in the middle. There is a built in valve on the unisync that you can open and close to get the manometer centered.
Once you get a clean reading on the manometer pull it off and set it on the other carb and read the manometer.
If the readings don’t match, and unless you have the Midas touch they won’t match then adjust the second carb to read the same as the first carb.
And you do that by adjusting the curb idle screw.
It’s very difficult to get both carbs equally open or a better way to say it is get both carbs flowing the same air at idle regardless of where the curb idle screws are at.
As Newbomb says, it's tough to get them right on the money. It's a balancing act, no matter what you do but you can get them very close.
Newbomb Turk
Well-Known Member
Here is the tool. As you can see, it's not for a four barrel, so you'll have to make an adapter like @Newbomb Turk described.
I plan on running 1:1. Have a single plane intake.
Thanks Troy, I was never successful getting the DQ and Eddys set up properly. I was in a rush, and wanted to get moving on the 340 build, so I pulled the setup off the 273 and shelved it for later on.
@str12-340 Mike was a big help with the progress I made. I enjoyed making the diy progressive linkage, but I didn't have much success with entire setup. I will revisit once 273 is rebuilt and on stand.
Here's my thread, might be some helpful info??
Dual quad info
@str12-340 Mike was a big help with the progress I made. I enjoyed making the diy progressive linkage, but I didn't have much success with entire setup. I will revisit once 273 is rebuilt and on stand.
Here's my thread, might be some helpful info??
Dual quad info
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