Recent Posts

Pages: [1] 2 3 ... 10
1
Quadrajet Parts and Numbers / Re: 7045264
« Last post by mcx on Today at 04:40:48 AM »
I'm looking for suggestions on what to use to make the cast plug mounted over the aneroid jet/screw removable.
Also, what is a good starting point for setting this screw?
2
Quadrajet Carb Talk and Tips / Re: 67 GTO 7027262 Fast Idle
« Last post by Mr.Pontiac on September 30, 2020, 06:35:16 AM »
Rick the hole in HIC is not ware screw is , it’s on top of the HIC passage towards top of bady
3
Quadrajet Parts and Numbers / Re: 7044276
« Last post by Kenth on September 29, 2020, 09:29:07 AM »
Cannot find the exact application, but i have restored at least one, jetting and calibration is a blueprint of the 7044266 1974 Pontiac Quadrajet.
Do you have the application code and date on your 7044276, it may be a late production unit?
4
Diagnose a Quadrajet carburetor problem / Re: throttle plate v.tubes filled
« Last post by F250 Restorer on September 29, 2020, 08:35:23 AM »
Thank you for taking the time to lead me through that. It took me a while to get it, ha ha, but I think the penny has dropped. Cheers.
5
Quadrajet Parts and Numbers / 7044276
« Last post by 4ever18 on September 29, 2020, 07:38:16 AM »
I have a Pontiac QuadraJet core,7044276, and I can't find any application information on it.  Can anyone help?

Thanks
6
Diagnose a Quadrajet carburetor problem / Re: throttle plate v.tubes filled
« Last post by Cliff Ruggles on September 29, 2020, 02:42:56 AM »
The long inner brass tubes are nothing more than airbleeds.  The size of the hole in the bottom of them varies with application.  Some models will even have an additional set of holes in the airhorn next to the tubes.  As the fuel is pulled up thru the large passages around the tubes it turns and makes it's exit via the large round nozzles.

The long tubes simply add some air to the fuel before it reaches the large discharge tubes and eventually into the intake and on down to the combustion space. 

One can actually leave the tubes out completely and plug the holes if you want to richen up the A/F ratio a bit and are enable to with small tipped secondary metering rods.  A few factory carburetors didn't use the tubes at all and we've had several customers that ended up blocking them off when converting to E-85 as it requires about 30 percent more of it that regular pump gas.

For what you are doing I'd leave them in place.  I'd also add here that some "builders" recommend shortening the tubes about 3/16" or so to get them up higher in the passages and out of the "short turn" (potential restriction) in the bottom of the main casting .  It is said that they can restrict fuel flow to the nozzles if left full length.  I've tested that theory and see no benefit anyplace shortening the tubes but it also doesn't seem to hurt anything either........Cliff

7
Diagnose a Quadrajet carburetor problem / Re: throttle plate v.tubes filled
« Last post by Kenth on September 29, 2020, 02:41:36 AM »
Yellow is fuel, blue is air and red is emulsified A/F mixture mixed in channels and out the nozzles.
8
Diagnose a Quadrajet carburetor problem / Re: throttle plate v.tubes filled
« Last post by Kenth on September 29, 2020, 01:56:36 AM »
The small brass tubes extend to the top of the air horn and adds air into the fuel in the fuel supply channels, not fuel to the nozzles.
The fuel to the secondary main nozzles are delivered up thru the fuel supply channels cast into the float bowl.
9
Diagnose a Quadrajet carburetor problem / Re: throttle plate v.tubes filled
« Last post by F250 Restorer on September 28, 2020, 05:09:12 PM »
We have a disconnect. I understand your explanation, but I don't think you are following what I am trying to say or explain. My secondary supply tubes are solid and extend to the top of the airhorn. There is NO way for the fuel to mix with air, unless it spews out over the top of the carb and is then sucked back down the secondaries. My understanding, as in your photo, is that the tubes have to terminate somewhere within the circumference of the discharge tubes so that the fuel can mix with air before being sucked down. Mine do not.

CLIFF, can you please tell me how to rectify this?
10
Diagnose a Quadrajet carburetor problem / Re: throttle plate v.tubes filled
« Last post by Kenth on September 28, 2020, 08:58:41 AM »
The inner tubes are sitting fine and supply air into the fuel and the emulsified fuel feeds thru the nozzles.
Click on the picture to enlarge and see better.
Pages: [1] 2 3 ... 10