AVS Carb is Kicking my A**

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rklein383

rklein383

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I am in the process of trying to rebuild an AVS carb for my 383-S fastback. The carb has been on a shelf for a long, long time.

I can't get the one of the secondary jets out.

I have drilled out the jet and am trying to use an easyout. The easyout is grabbing good but it won't budge. I have tried a good soaking of penetrating oil and even a little heat from a propane torch. It doesn't want to come out. I already got one of the primary jets out this way.

Any ideas on what to do besides more penetrating oil and letting it soak a longer time?

Thanks,
Rod
 
Gosh. I very, very rarely ever remove them during a rebuild. I don't know what to tell you. I guess you could do like a broken bolt and drill right below the threaded size and pick the rest of the jet out.
 
RustyRatRod said:
Gosh. I very, very rarely ever remove them during a rebuild. I don't know what to tell you. I guess you could do like a broken bolt and drill right below the threaded size and pick the rest of the jet out.
Click to expand...

If I would have ever ran the carb, I might have left them in. But I have absolutely no idea what the "professional" before me had done, so I wanted to replace them with new ones.

I might end of drilling them it out as you suggested, but if I mess up the threads, the carb is probably a junker.

Rod
 
I don't know. I think those are regular straight bolt threads. A heli coil would repair it. BUT I suggest coating the threads with rtv when you reinstall the jets. They will never seize again.
 
RustyRatRod said:
I don't know. I think those are regular straight bolt threads. A heli coil would repair it. BUT I suggest coating the threads with rtv when you reinstall the jets. They will never seize again.
Click to expand...

I have never had jets frozen like these ones are. I don't think this carb has been on a car for decades.
Rod
 
-The two materials have fused by a chemical process, between dissimilar metals, called; Wait for it... Oh I remember Electrolysis, I think. At the boundary between the metals will form a dry semi-course powder similar to cured loc-tite.It will physically lock the metals together.I think your only hope is heat. Oven heat.
-The hands down most awesomest penetrant I have ever found is a heat-riser solvent from Ford.
-If that dont work I would throw it in the oven for, say a half-hour at around 200ish.The aluminum will expand more than the brass. Put your easy-out, and its driver in the freezer for an hour or more.Wear gloves and work fast. Slam the tool in the jet and see what happens.Remove any plastic bits beforehand.If it doesnt work right away, put a drop or two of water on the easy-out and let it run down into the jet. Do not work on a metal surface. Try a large wooden board, anchored to the bench. with a couple of studs protruding up out of it for the carb base to sit on. Speed is of the essence, not force.
Sounds like a lot of work. And it is. It may take several tries, as you learn the method.I have never done this to a carb. I have taken other things apart, successfully, using this thinking.The carb has to stay hot, and the jet cold. Its the temperature difference that will do the work for you, not the force on the easy-out.A blanket on the aluminum may help.
Best of luck to you.
 
OK OK here is THE trick.. get the torch heat the jet till the flame color changes. then dump water on it. i know the flame will not want to run in the bowel. so just keep trying. your welcome. buy NOT taking them out is better. course at times you must.
 
Moe. Thats a great idea. Have you done many? I would imagine its pretty tricky. I mean it wouldnt take much of a mistake to melt the aluminum, and ruin the casting forever.I know I wouldnt be that brave.Maybe on my own carb.
 
Bolt freeze if you want to try it on the jet. Heat it up then hit it with the freeze (like freon held upside down) it may break the bond. If all else fails, drill it out, press a brass plug into the hole and retap. acetone/ATF mix is pretty good on a sunday eve when the stores are closed.
 
Thanks for all the great tips! Will keep you posted.
 
Or you can buy the AVS I have rebuilt and ready to go.
 
Your might try AeroKroil. Soak it overnight.
If that doesn't work, drill the jet and peel the brass out of the body threads with a pick. It's softer than the base metal.
 
Here is the update:

I drilled out the jet with a drill just slightly smaller than the diameter of the hole. I couldn't quite get the brass out like Captainkirk suggested, but a 5/16-24 tap was able to chew the remaining part of the jet out.

Looks like I saved the carb, will need to do real good job of cleaning it due to the fine brass shavings that I produced.

Also need to determine a good baseline jetting and metering rods for it.

I am rebuilding the 383 that goes in my 383-s. My son has a good Edelbrock carb that I will throw on it for initial breaking in of the engine.

Thanks for the tips.
 
have i done many AFBs? only 1-2 hundred. i had 30 AFBs before my divorce. i have posted some about the AFB. that Aluminum will take more heat that you think. do you ever weld Al? get a big block of Al and lay your torch on it and see how long you meld a hole in it. your torch is not as good at heating Al as a TIG rig is.
 
this is my instruction set for jetting an AFB / AVS.
This is a verson of a program I did for the Commodore computer. That my son did for PCs.
1. this program can not tell what jets to run. It can only tell you % diff of the jet you are looking at to change. When doing jets only enter .000 for all rod enterys.
2. 2. the label jet#1 , or jet#2, means the jet and the two steps on the rod.
3. The top box is for the jet number only like this .065
4. the second box is for the economy step, the largest dia of the rod. .085
5. the power step smallest dia goes in the bottom box. .075
6. test#1: jet#1 .100-----jet#2, .110 = 17.355% arrow will point to the left meaning more fuel.
7. Test#2: jet#1 .100 jet, power step .065 econo step .075 jet#2 .100 jet, power step .067 econo step .077 = 6.948% leaner arrow points to the right.
8.
9. All this means you CAN calculate both jet AND rod changes
10. for Carter AFBs and AVSs.
11. http://clarkehackworth.com/files/JetsAndRods.html
 
Hay glad you got it out. Don't forget my RTV tip when you put the jets back in. They will never seize up again. You need to let the RTV cure completely though.
 
i never thought of RTV on the jet. sounds like it should work. i thought of anti-seize compound but never tried it. i havent done any AFBs for 10 years. the last one was a 1965 buick 300 ci engine, in a small wagon. for my electronics teacher. but i could not do for free, cause he was my teacher. i have thought about an electronic rod controller. but its still just an idea. some one needs to check out an arduino control.
 
RTV turns to gelatinous globs when immersed in fuel. I didn't believe it until I tried it. Just sayin'...
Maybe when on the threads it doesn't get affected?
 
Next questions:

The primary jets that came out of the carb had a "shoulder" on them. The secondary jets looks just like the ones available today.

Is there a difference in the construction of the primary and secondary jets?

Also, according to a couple of websites, gas today is not the same as in the 60's and they generally recommend jetting up for a richer mixture. I live at 3500 feet so I need to jet down to lean it out. I thinking about sticking with the stock jetting and hopefully between jetting up for the bad gas and jetting down for the altitude, I might get it about right with the stock jets.
Any suggestions. Primary-.089 Secondary-.092 were the stock sizes. 16-164 for metering rods

Rod
 
Captainkirk said:
RTV turns to gelatinous globs when immersed in fuel. I didn't believe it until I tried it. Just sayin'...
Maybe when on the threads it doesn't get affected?
Click to expand...

I've seen it happen when RTV does not cure completely. When it has set for 24 straight hours, it is impervious to fuel. That is the Permatex brand. I cannot speak for the lesser quality brands.
 
on chryslers the O.E.M. AFBs can have two defferant JET configurations. on the PRI jets, rods, cover. 1. the first has a flat cover, with short rods w/ 2 steps., short jets. 2. the other has a domed cover, long rods 3 steps, and tall jets. these may have a diff numbering system. DO NOT mix the long and short parts.
 
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