Found a Quadrajet

[Mr. Machanic]

Hot diggity!!!
I was looking for a doner-jet.
Found a local 1705 7213. Mine's a 8213.
I couldn't ask for better and the price was great.
To me it's worth the education.
When I worked on bikes (GL1000) I was always willing to pay for a chance to get educated. Because ignorance is way more expensive than knowledge.
I am a technical manual nut and I'll drive hours for a doner project.

Any who, this carb is about to get the works.
It has loose butterfly rods that need bushings installed.
There are rods missing and who knows what else.
My goal here is to rebuild this carb and then swap it out with the one on the truck and then rebuild that one and return it back to the truck.
This way, I don't lose the use of the truck and I still have a running carb, in case I bugger this one up beyond servicability.
Fingers crossed.

BTW, has anyone used the Kevin R. Hill book, The QJ MPG Secret...?

I've read it...the jury is still out.
I do have 4 manuals on the truck and a .pdf on QJ's. All of which I've read.
If you happen to know of a good QJ manual, please let me know.

I will take photos as I go and if you have any insight or suggestions, feel free to post...
..as long as it's not a suggestion to throw on a Holley....my high school from the same era as the truck suggested that already...he's not helpful either...lol

[Captkaos]

I personally wouldn't run anything on a driver car but a QuadraJet if I didn't have EFI.  https://cliffshighperformance.com/ is one of the goto places for Quadrajet rebuilds or info.  The owner wrote this book: " "How to Rebuild & Modify Quadrajet Carburetors" available on his site.

story on how to modify for todays Ethanol gas: https://www.motortrend.com/how-to/quick-tech-ethanol-friendly-q-jet-rebuild/

Well Plugs and shaft bushing were the main issues on them from the past.

[Mr. Machanic]

His book was ordered last night...along with a couple others.

[Mr. Machanic]

This is the original 78 QJ on the Big 10.

[Mr. Machanic]

Here's the same 1705 QJ, just a 77 instead of a 78.

[Mr. Machanic]

Got it all pulled apart.
Oh, that was fun! Seriously.

In the throttle plate, the primary shaft is worn and it shows on the shaft. It's .005 or .006 undersized. The unworn diameter is .308 and the worn spot is .303 and it is easy to see the movement in the throttle body plate.
I can seem to find primary shafts. Secondarys are easy to find. Just not the primary.
Any websites that may have a good one?
Thanks.

[JohnnyPopper]

Looks like you pulled it from the bottom of a pool...hope she cleans up, will be watching this thread. I've done my share of QJ rebuilds with mixed results.

[Mr. Machanic]

What is this "thingy"?

[Mr. Machanic]

So....
I was not aware of this broken boss when I purchased the doner.
It was night time and out in the middle of sellers drive. (No excuses, just info)
The tube is slightly bent, but I can straighten that, or make a new one. No big deal.
The boss repair will be an interesting challenge.
But first, a bath. As my kids used to say, "It's poofy." They couldn't say, "filthy".

[Mr. Machanic]

The plan is to sleeve the boss.
First, the tiny raised ridges on each surface is taped off so they are easy to see.
Next the body is lightly clamped up to angle plates as the little plane is indicated flat.
Then the boss is indicated in to align the spindle to its center.
Once all of that is done, the fractured pieces are removed and then the boss is given a clean deck.
You might notice the 3/16" tube hole is not concentric to the boss, so the center of the hole is picked up and that becomes the new center.
Now the boss can be externally bored to generate a true and straight boss to receive the sleeve.
The endmill is switched out for the boring head and a minimal amount is removed to accomplish the desired geometry.
Measurements are taken and a sleeve is machined to match.
A light press fit is made and then the 3/16" hole is reamed thru to the original hole.
The sleeve was made a few thousands long and now it too is decked off to match the adjacent boss which supports the vacuum plate.
Burrs and chips are removed and it's done.

[Mr. Machanic]

Sorry, can't load more than 1 pic at a time.

[Mr. Machanic]

Another pic

[Mr. Machanic]

Missed resizing a pic...my bad...

Forgot to give ya some numbers.
The original boss was .312 diameter plus the draft and .870 height.
By the time it got all cleaned up, the boss was .284 dia. X .400 height.
The sleeve is .370 with a bore for the boss.
So the finished boss is .370 dia X .870 height.
That's only .060 larger than original.

[Mr. Machanic]

How many of you have broken off this little tab?

Well, count me as one among ya.

As part of the damage when the afore mentioned boss and tube was hit, the bracket with the vacuum actuator was badly bent. So I took a small punch and slowly worked the little metal tab open so the vacuum act. could come out It was more than she could handle and that tiny tab all but fell off.
So, do I cut another piece of metal and weld it in? Man, that is some fine work and I do not have a TIG unit. Well, the family happenins made me set it aside, but my mind was working on it while we were away.
Back home and I grabed a 1/8" stick welding rod, hammered off the flux and cut off about 5".
I ground a little step to give the solder a place to bite and cleaned it all with a wire wheel.
Set it all up on a fire brick and within a few minutes it was silver soldered in.
A little filing to get the fit and the actuator dropped in.
Once painted and ready for final assembly then the finger will get "adjusted" with a hammer. Here's to fingers crossed hopeng the silver solder can take a little "adjustment".

[Mike81K10]

You seem to have many issues with that Carburetor. I would find another that is in better condition or buy one already rebuilt. It would be about the same cost to do the repairs and rebuild your own.