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Eddy carb question

Hilljack68

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I have a E-brock 750 on my 340. I've noticed the rear barrels don't kick in; they gradually open. My question is this: the weights on either side of those butterflies (the ones that actually open the throats)... Do I need to reduce their weight? Either by shaving them down or drilling holes in them? Any thoughts?
 
btw,i just realized you said 340.
any reason you dont run a thermoquad ??
those are 800cfm/1000cfm and super fuel efficient.
thats really the best carb for those,unless you are running a full race motor.
 
Thanks for the vids! The Uncle Tony video, as always, is very enlightening.
 
You probably have a AVS which is a "adjustable valve secondary". Yes they open progressively against spring pressure and not like a mechanical secondary Holley
 
btw,i just realized you said 340.
any reason you dont run a thermoquad ?

Well, I guess I didn't do a whole lot of research before I bought. Some, but not a lot. I leaned away from Holley very quickly (just because I don't race her). But for my purposes, I thought the Eddy would be my best bet.
 
Well, I guess I didn't do a whole lot of research before I bought. Some, but not a lot. I leaned away from Holley very quickly (just because I don't race her). But for my purposes, I thought the Eddy would be my best bet.
Which carb did you buy?
 
Model 1411/1407 are not AVS models

Yes they have weighted air doors , that are not adjustable - Mechanical secondaries

1411/1407 also come in handy as very good paper weights
 
Well, here's my objective: A weekend cruiser, not a drag strip car, gas mileage somewhere north of 12, the ability to punch it and pass that stupid Nova when I come up on it.

I'm not a carb expert, and I realize there will be a hundred people who favor the one they're using, but I am open to constructive and helpful suggestions.
 
Well, here's my objective: A weekend cruiser, not a drag strip car, gas mileage somewhere north of 12, the ability to punch it and pass that stupid Nova when I come up on it.

I'm not a carb expert, and I realize there will be a hundred people who favor the one they're using, but I am open to constructive and helpful suggestions.
It will work fine but by design you won't feel (or hear) the secondaries kick in like a Thermoquad, Double pumper Holley, or Quadrajet.
 
Maybe a 1906 650 AVS2 would work better.
Edit: I would also suggest the 9266 insulator if hood clearances permit.
 
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I don't think anyone answered your question, but I didnt watch the vids either.

The answer to your question: Yes. You can change the weight of the counter weights to activate the secondaries sooner and faster. I do drill holes in them so if you go to far, you can more easily go back and add the weight back in.
 
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I have a E-brock 750 on my 340. I've noticed the rear barrels don't kick in; they gradually open. My question is this: the weights on either side of those butterflies (the ones that actually open the throats)... Do I need to reduce their weight? Either by shaving them down or drilling holes in them? Any thoughts?

If the secondary side opens slow, it is telling you that the engine is eating and breathing in the extra air and fuel slowly because that’s all it needs.

I personally do not suggest grinding the counter weight door for a few reasons.

1: Your not racing.
2: The counter weighted doors are not a part you can purchase separately.
3: The door is weighted for street and some strip performance as delivered.

4: is my question to Rus below.

btw,i just realized you said 340.
any reason you dont run a thermoquad ??
those are 800cfm/1000cfm and super fuel efficient.
thats really the best carb for those,unless you are running a full race motor.

Rus, what are you adding to a over cut counter weighted door for putting weight back on?

The actual true 800 & 1,000 TQ carbs are the race versions. The stock OE versions are far less but just simply referred to at 800 & 850 cfm’s. The else trick choke aftermarket over the counter TQ is considered the small on due to the 1-3/8 primaries @ 800 cfm with an actual around the 760/770 area.

With a TQ, I do not suggest an adapter to mount the carb to a dual plane square bore intake. It is fine for tuning purposes on a single plane. Slow is a Mr. Gasket 1 inch spacer, NOT an adapter specifically designed for the TQ.
(P.S. That home made bracket is a Lokar trans cable hook up point.)
01D95D20-F092-4244-8156-B872331CD2E9.jpeg
 
And just food for thought: I'm running an LD340 dual plane intake.
 
it wasnt me that suggested drilling the holes in the weights sorry rumblefish.
i kinda wondered about that myself.

yes,you are correct i wasnt really thinking about pointing out the differences between the competition series and the reg thermoquads.
i still stand by my original statement tho,a thermoquad is what i would run.
esp after finding out hes running an ld 340 intake.
i run the cop car and the truck carbs myself,no smog and lots of deep breathing.
plus that howl as you are passing others is sweet music.

btw,to hilljack,
that first vid was kinda blah blah blah but uncle tonys vid was rocking wasnt it ?
heres another fairly interesting one and highly applicable here.

 
@BeatersRus , OH! Sorry about that. Anyway.....

Note the adjustable throttle linkage and the manual choke cable bracket on the race TQ below.
4ECAFB7D-4385-439A-986F-8D69A99F9852.jpeg
9F40C091-1E87-4C30-9003-8C67F123668E.jpeg
4ECAFB7D-4385-439A-986F-8D69A99F9852.jpeg
9F40C091-1E87-4C30-9003-8C67F123668E.jpeg
 
The answer to your question: Yes. You can change the weight of the counter weights to activate the secondaries sooner and faster. I do drill holes in them so if you go to far, you can more easily go back and add the weight back in.
Once you drill holes in the weighted door, what do you use to refill the holes back to the as delivered weight and balance?


And just food for thought: I'm running an LD340 dual plane intake.
Is the intake still as cast or is it modified?
If it is still as cast, the TQ will need an adapter. At the least, you’ll need the stock thick gasket and maybe you can grind the edges so the secondary butterflies can clear.
 
Funny. You wouldn't change the counter weight on an AFB, but the carbs by Carter that followed all came specifically designed for the owner to adjust the secondary air valve. So , apparently, in the early 1960s, Carter made them perfect, but after that they forgot how to make them perfect and therefore adjustable.

Just like any carb, you won't know what will happen until you try it. Nearly every day on this forum people discuss the dozen things to change and adjust on a manufacturer's factory calibrated carb to make it better.

I've modified and track tested counter weight reductions on my original Carter 4327 AFB. I probably drilled 6 holes in each weight and the car kept going quicker and faster. It never got slower, so I never added weight back in, but certainly a little solder would do the job.
 
Solder is a different weight than aluminum.
This is why I asked.
Going faster, in your application, is good to hear. This is not a clear and definitive route to take for all applications.
And once you go to far, a new one is not available but a core would provide a replacement.

The AVS & TQ may have adjustable secondary air door settings but they were not designed for the public to fool with them even though they could. To say they were designed that way, for the public to screw around with, is an insane statement and even crazier to actually believe in.
 
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