The 49 year old factory AVS may not be down for breakfast

[Richard Cranium]

I give up on it & I think it's time to replace it with an Edelbrock Performer carb. For a stock 440, which is the best one to get & who's got the best price?

 

[moparwacko]

You really mean stone stock right?
If you're stuck on an Edelbrock, the Thunder 650 AVS. Still may have to do some tuning, but great stock application.
What's wrong with the original?
Can't be rebuilt?
Just about all the big houses have the same price. If no rush, Edelbrock often throw rebates a couple times per year.

 

[oldbee]

RC I feel your pain, I think mine is seeping from every orifice that was ever sealed/plugged from the factory.

 

[AMX364]

The Street Demon might be a better fit. The Edelbrock 750 has a reputation of issues, jetting and not working well with the current type of gas.

 

[WileE]

Either 1411 750cfm, or the 1413 800 cfm, depending on your setup. Both are electric choke. I've used the 750 on a few engines over the past few years, tuned them & ran well, no complaints.

 

[BeatersRus]

just an off the wall question,has anyone used the thermoquads?
i have a 650 eddy on my 440 already and was thinking about playing with the quad.
i have 3 or 4 laying around,and was debating performance value.

The Thermo-Quad was available with two primary throttle bore sizes, 1-3/8" and 1-1/2". Flow ratings (CFM) vary depending on the source, but the TQs with the 1-3/8" bores are listed as 750-800 CFM and those with the 1-1/2" primary throttle bores are rated at 800-850 CFM.

 

[idrivemopar]

just an off the wall question,has anyone used the thermoquads?
i have a 650 eddy on my 440 already and was thinking about playing with the quad.
i have 3 or 4 laying around,and was debating performance value.

I have been messing around with thermoquads on my 340 for a few years now. I started with the 6319(small bore) and it was the original, but it ran rough, mainly I think because of the pitting form corrosion on the top and bottom plates, so I switched to a 6322(large bore) and it runs smooth, but I still have a WOT lag that I cant get worked out, if I could I would stick with that one, otherwise I may have to go with modern carb!

 

[BeatersRus]

we used to have a Guru down south who could dial them in,
and we stuck them on 383-s and wow would those jokers run.
they make an ungodly Howl that can be heard for a country mile,
i miss that sound and was wondering if was worth doing again.

on the bog its your secondary opening too soon?
it can be adjusted.
im actually putting on my shoes to go dig out a few of these and see what i have.
info for anyone who likes quads
http://www.carbkitsource.com/carbs/tech/Carter/pages/tqguide-Vaanth.html

 

[Richard Cranium]

What's wrong with the original?

It's running lean at idle & the only adjustment is that useless LH threaded center air valve screw. The idle mixture screws are the non-exposed types that have been leaded over. However, I dug the lead out to expose the screw heads and neither one is budging in either direction. I'll try those again later on, but I'm just looking for a suitable newer replacement for my stock carb if all else fails.

 

[chtampa]

I had an AVS on my 69 383 that had an off idle stumble, lean issue, always changing idle RPM, Burning plugs, and overheating engine. I even bought an A/F reader and put two O2 sensors in the exhaust chasing the problem. The ratio jumped around like crazy. Gave up on it and bought an Edelbrock, same problem. Bought a smaller CFM Edelbrock, same problem. Bought another restored factory AVS, same problem. Ended up being a leak in the intake to head/valley pan seal. Replaced the metal valley pan gasket and glued it all together with extreme prejudice. Problem solved and then I had 3 extra carburetors. A/F ratio settled down and lost the stumble, lost the lean issue and got the overheating problem under control. Machine shop surfacing on the head and deck had apparently caused a fitment problem. I did leave a wood spacer under the carb to help with vapor-locking.
I went to so many experts and no one could find the problem, so the intake seal was an act of desperation. I went looking for damage to the intake flange, found none and decided to glue the intake back on anyway. I got lucky.

 

[Richard Cranium]

Replaced the metal valley pan gasket and glued it all together with extreme prejudice.

I have done the same as well.

 

[68GTXNH]

this goes right back to modern gas and ethanol screwing with good old technology. alot of great original carbs are in junk piles because of the epa...
if you need a new one, id avoid edelbrock. theres a reason dyno shops almost across the board all have a higher price for any car they tune with an edelbrock on it. where in mass are you? hobbs carburetor in Pelham nh, (on the south east NH border) can make that carb like new for you. hes the guy all of us in the area go to. worth a shot to ask him. edelbrocks can be good if they work right out of the box, but every motor is a little different. if you have to dial it in its more of a pain in the *ss. if you feel you need a new carb, and dont want to rebuild the old one, id go with holley. i basically use them exclusively. theres a reason theyve been around since 1896....

 

[lewtot184]

RC, try a 750 edelbrock. change the primary jets to .104" and use 65x52 metering rods.

 

[Bruzilla]

I think I've made my thoughts on Edelbroke carbs pretty clear. If you're gonna buy one, get yourself a supply of gaskets as you're gonna be opening it up again and again to adjust those DAMN floats. Like Carters, these things are susceptible to heat, even with spaces, and those brass floats are mounted using thin brass strips that I suspect warp as they get hot and cool off.

 

[Richard Cranium]

Got the (internal) mixture screws out finally. What a PIA. I'll throw it back together & try it out this evening as one last shot.

 

[chtampa]

I think I've made my thoughts on Edelbroke carbs pretty clear. If you're gonna buy one, get yourself a supply of gaskets as you're gonna be opening it up again and again to adjust those DAMN floats. Like Carters, these things are susceptible to heat, even with spaces, and those brass floats are mounted using thin brass strips that I suspect warp as they get hot and cool off.

My restored AVS has the Edelbrock floats in it and I have had them leak fuel and fill the floats twice so far. I still have one that won't leak any of the fuel back out. It sealed itself back up. Cue the Twilight Zone theme.

 

[lewtot184]

Got the (internal) mixture screws out finally. What a PIA. I'll throw it back together & try it out this evening as one last shot.

while your at measure the i.d. of the idle tube (the small brass tube attached to the primary cluster). it will need to be at least .035".

 

[lewtot184]

My restored AVS has the Edelbrock floats in it and I have had them leak fuel and fill the floats twice so far. I still have one that won't leak any of the fuel back out. It sealed itself back up. Cue the Twilight Zone theme.

if a float "leaks" it's full of fuel and won't control flow, or are you referring to empty fuel bowls?

 

[Bruzilla]

My restored AVS has the Edelbrock floats in it and I have had them leak fuel and fill the floats twice so far. I still have one that won't leak any of the fuel back out. It sealed itself back up. Cue the Twilight Zone theme.

I had one do that too! It happened right after a tornado went by, and I thought the drop in pressure had allowed the float to open and then close when air pressure returned to normal, but I guess this is an oddball issue with these crap floats.

 

[Daves69]

I give up on it & I think it's time..............

A 4638?