Author Topic: 66 Quadrajet Fuel Bowl issue  (Read 2361 times)

Offline ElCid

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66 Quadrajet Fuel Bowl issue
« on: October 16, 2018, 10:43:26 AM »
Hi all.

New member here. Great site!

It has been at least 20 years or more since I rebuilt a Quadrajet. I have been toying with Dellortos, Webers, Holleys, etc. for cars and bikes in between. Anyway, I am putting back the original carb to my 66 caprice after letting it sit for some time and needing a rebuild. I noticed it has a post mount (not sure what to call this) broken off?. I do not know what happened but being an earlier (66) carb this area is sealed unlike later units which appear to have a vacuum there.

I mocked up the linkages and lower throttle body plate assembly and really do not see much of a need or concern for what was there. Does anyone know if this will be a problem? Does it work as a stopper for the plastic weight behind the choke lever and vacuum diaphragm assemblies?

Carb is a 7026202. I probably shouldn't bother as these early ones weren't the most reliable but it is one of those 99.8% all original numbers matching cars....

Any info appreciated. Thanks.






« Last Edit: October 16, 2018, 10:48:02 AM by ElCid »

Offline Sonny

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Re: 66 Quadrajet Fuel Bowl issue
« Reply #1 on: October 17, 2018, 07:55:47 AM »
The broken post is part of the choke system. Off hand I don

Offline ElCid

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Re: 66 Quadrajet Fuel Bowl issue
« Reply #2 on: October 17, 2018, 05:32:30 PM »
Hi Sonny. Thanks for responding. I think your post got truncated for some reason. May you please repost your complete response? Thanks.

Offline Sonny

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Re: 66 Quadrajet Fuel Bowl issue
« Reply #3 on: October 17, 2018, 06:07:27 PM »
I do not know if the broken post on your main casting will cause you problems. I am new here too so let others offer their experienced opinions.

Since the post is not drilled I assume your carb is divorced choke. My carb is divorced choke and that post simply serves to support the choke linkage assembly. There are two additional points of support for the assembly so perhaps you are okay.

(The truncation occurs when posting from iPhone and using an apostrophe. Assume the char set used by my iPhone is not fully compatible with the forum software. This old programmer says I can fix that with one line of code. HA HA)
« Last Edit: October 17, 2018, 06:14:17 PM by Sonny »

Offline 429bbf

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Re: 66 Quadrajet Fuel Bowl issue
« Reply #4 on: October 18, 2018, 07:38:00 PM »
how handy are you ? you can drill and tap both pieces to fit a   no 6 screw take a short length of screw and add a small spot of marine tex and screw them tight good as new . hth

Offline ElCid

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Re: 66 Quadrajet Fuel Bowl issue
« Reply #5 on: October 18, 2018, 07:54:12 PM »
how handy are you ? you can drill and tap both pieces to fit a   no 6 screw take a short length of screw and add a small spot of marine tex and screw them tight good as new . hth

I like your idea but unfortunately I do not have the piece that broke off. I suppose I could make something, even out of plastic or other metal and put in its place. I'm just wondering if it is even worth the effort. If I do not really need that to support the choke assembly I can just as well do with out it. I am thinking two of the three mounts would be sufficient to secure everything but not really sure what sort of pressure the carb is under while driving.

From an engineering standpoint, I assume there is a reason it was there.

Offline Sonny

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Re: 66 Quadrajet Fuel Bowl issue
« Reply #6 on: October 19, 2018, 09:32:02 AM »
Here is a picture of three posts.

Offline Cliff Ruggles

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Re: 66 Quadrajet Fuel Bowl issue
« Reply #7 on: October 30, 2018, 02:10:22 AM »
There are several methods we use here to make those repairs if the original piece is missing.

A brass tube can be used with a #10-32 screw after tapping into the casting about 1/4" or so.  The brass tube is cut to length to keep the choke bracket the correct distance from the main casting......Cliff

Offline Cliff Ruggles

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Re: 66 Quadrajet Fuel Bowl issue
« Reply #8 on: October 30, 2018, 02:12:26 AM »
I'd add here that for the most part I try to avoid 1965-66 units.  They are always quite a challenge to get rebuilt, restored and working OK.

Even with ones best efforts they lack certain features of the later units making them somewhat lacking in performance, reliability, etc........Cliff

Offline ElCid

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Re: 66 Quadrajet Fuel Bowl issue
« Reply #9 on: October 31, 2018, 07:47:10 PM »
There are several methods we use here to make those repairs if the original piece is missing.

A brass tube can be used with a #10-32 screw after tapping into the casting about 1/4" or so.  The brass tube is cut to length to keep the choke bracket the correct distance from the main casting......Cliff

It has been my experience as well that early qjets aren't the easiest or most reliable. I like the suggestions about using a screw with a small tube. I'm party curious to rebuild it and see how it runs. The air horns is definitely bent so I have been working slowly to correct all of that. If it goes in and behaves, I will keep her. If not, I will stay with the '75 that is on it now.

Thanks everyone!

Offline Cliff Ruggles

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Re: 66 Quadrajet Fuel Bowl issue
« Reply #10 on: November 01, 2018, 04:29:50 AM »
Pressure test the bypass system after plugging it as most will leak at the small aluminum plug just behind the fuel filter housing. 

Complete waste of time/funds to install the brass plug with the "O" ring to block the bypass, they end up leaking after a few weeks or months.

Even with the revised N/S conversion those carbs are difficult to keep full on hard runs with decent power levels.   They also are HORRIBLE for transition onto the secondaries, no POE and "goofy" weighted valve vs using the pull-off to dampen the opening rate.

For sure I would get one of our kits for it, and ask for the HP accl pump assembly.  This will provide additional fuel to help cover a lean condition when the secondaries come in........Cliff