Carburetors - Gary's Musings

[Gary Lewis]

I remember those little springs being a pita, so yes, it does have them.

The kit I ordered was for all AVS and came with both styles

Like I said the carb is good, but runs out of gas on my cammed and straight up 460.

A 650 is small for a breathed-on 460. But it may be just right for a stock 460. And if you have the solid needles they could be swapped out.

[85lebaront2]

Yes, all the seats are compatible with the springs-loaded needles, which Edelbrock is saying are for “off-road” use. But weren’t spring-loaded needles used on several GM’s routinely?

As for the step-up spring, both the 1825 and 1826 use the same one, which pops the rods up at 5” of vacuum or less.

And I’ll bet the AVS sitting in my ‘69 Bee is the one with the taller jets and longer rods. I’ll check.

Speaking of AVS, or Air Valve Secondary, Edelbrock is re-using that name they acquired from Carter. They now have an AVS2, which has annular boosters. There’s a neat video that shows the difference. So those, like Fonzie, that tout the annular boosters have a new carb to consider. In fact, we’re I buying a new carb I’d consider it, although I suspect the price is high.

Gee, annular boosters, I guess Ford's patent has long since run out on that design. Every time I see someone else singing the praises of those all I think about is 1957 FoMoCo carburetors and how different they looked from Holley and Carter designs as Ford used all 3 in 1957/58. After that they sort of used Carter on most Lincolns, Holley for performance and FoMoCo, later Autolite and finally Motorcraft on most run of the mill production.

Interestingly, the 1100 (single barrel) was the last introduced and probably the shortest run, from 1963-68 or 69 and was the only one without the annular booster. the 4100 disappeared at the end of 1966, so was out for 10 production years, 1957-1966, the 2100, became the 2150 and was around from 1957-1985 or 1986. The 4300, again no annular boosters, 1967-1970, 4300D 1971-1978, maybe 79 in trucks.

[Gary Lewis]

Gee, annular boosters, I guess Ford's patent has long since run out on that design. Every time I see someone else singing the praises of those all I think about is 1957 FoMoCo carburetors and how different they looked from Holley and Carter designs as Ford used all 3 in 1957/58. After that they sort of used Carter on most Lincolns, Holley for performance and FoMoCo, later Autolite and finally Motorcraft on most run of the mill production.

Interestingly, the 1100 (single barrel) was the last introduced and probably the shortest run, from 1963-68 or 69 and was the only one without the annular booster. the 4100 disappeared at the end of 1966, so was out for 10 production years, 1957-1966, the 2100, became the 2150 and was around from 1957-1985 or 1986. The 4300, again no annular boosters, 1967-1970, 4300D 1971-1978, maybe 79 in trucks.

It is interesting to me that there are still "new" carbs coming out. But, they aren't really new as they are, for the most part, just packaging features that have been used heretofore into better carbs. For instance, the Street Demon that was designed by an ex-Carter engineer and has, oddly enough, many of the good features from the Thermoquad and AVS. And now Edelbrock picking up the annular boosters from Ford and adding them to the AVS.

And, here's a pic of the AVS on the Bee. The red arrow shows the raised cover for the longer metering rods that Bill was talking about. The green arrow shows the spring that keeps the air valve closed until a pre-set flow is achieved, and the yellow arrow shows the screw that adjusts that pre-set point.

[85lebaront2]

It is interesting to me that there are still "new" carbs coming out. But, they aren't really new as they are, for the most part, just packaging features that have been used heretofore into better carbs. For instance, the Street Demon that was designed by an ex-Carter engineer and has, oddly enough, many of the good features from the Thermoquad and AVS. And now Edelbrock picking up the annular boosters from Ford and adding them to the AVS.

And, here's a pic of the AVS on the Bee. The red arrow shows the raised cover for the longer metering rods that Bill was talking about. The green arrow shows the spring that keeps the air valve closed until a pre-set flow is achieved, and the yellow arrow shows the screw that adjusts that pre-set point.

Damn Gary, that AVS on the Bee looks like it has been around here from all the oxididation,

The AVS was apparently in addition to (a) putting the air valve above the fuel delivery and (b) increasing the air flow on the already good size "Daytona" AFB derived from the "Daytona" AFB bowl and air horn castings. The "Daytona" AFB had the large air filter circle like Ford used.

[Gary Lewis]

Damn Gary, that AVS on the Bee looks like it has been around here from all the oxididation,

The AVS was apparently in addition to (a) putting the air valve above the fuel delivery and (b) increasing the air flow on the already good size "Daytona" AFB derived from the "Daytona" AFB bowl and air horn castings. The "Daytona" AFB had the large air filter circle like Ford used.

It’ll have to be bead-blasted if I’m to use it again. But is that an “emissions” carb? Is there really any reason to run it on anything?

[85lebaront2]

It’ll have to be bead-blasted if I’m to use it again. But is that an “emissions” carb? Is there really any reason to run it on anything?

It is emission in the sense it has leaner jets and is set up to run off the idle transfer slots at curb idle. I will have to take another look at the pictures, some of those had a "sealed" idle air bleed in the front center. At least that one has an external bowl vent, and two (probably frozen) idle mixture screws. Biggest emission change on that engine was the retarded initial timing which on Chrysler engines made them very prone to hot start backfires if the throttle was too far open. You used to be able to hear one clear across a parking lot, the ying, ying, ying of the straight cut gears in the starter followed by BOOM, roar when it caught.

The center lead plug on the main body, just under the gasket is the factory sealed idle limit setting, it is an air bleed into the two idle circuits so it affects both the "adjustable" mixture and the idle transfer slot mixture. Emission compliant carburetors were modified so that they could run a retarded timing and as a result a leaner idle mixture. To limit the adjustability, the transfer slots were enlarged in length so the normal curb idle position uncovers them. As a result the idle "mixture" screws become mixture trimming screws and even at full rich setting are still lean enough to satisfy the EPA rules in effect at that time. Chrysler elected to do engine modifications to meet the 1968 clean air regulations, Ford used modifications on automatic trans applications and Thermactor (air pumps) on manual trans. GM, each engine family was different. AMC, same as GM for the most part.

[Gary Lewis]

It is emission in the sense it has leaner jets and is set up to run off the idle transfer slots at curb idle. I will have to take another look at the pictures, some of those had a "sealed" idle air bleed in the front center. At least that one has an external bowl vent, and two (probably frozen) idle mixture screws. Biggest emission change on that engine was the retarded initial timing which on Chrysler engines made them very prone to hot start backfires if the throttle was too far open. You used to be able to hear one clear across a parking lot, the ying, ying, ying of the straight cut gears in the starter followed by BOOM, roar when it caught.

The center lead plug on the main body, just under the gasket is the factory sealed idle limit setting, it is an air bleed into the two idle circuits so it affects both the "adjustable" mixture and the idle transfer slot mixture. Emission compliant carburetors were modified so that they could run a retarded timing and as a result a leaner idle mixture. To limit the adjustability, the transfer slots were enlarged in length so the normal curb idle position uncovers them. As a result the idle "mixture" screws become mixture trimming screws and even at full rich setting are still lean enough to satisfy the EPA rules in effect at that time. Chrysler elected to do engine modifications to meet the 1968 clean air regulations, Ford used modifications on automatic trans applications and Thermactor (air pumps) on manual trans. GM, each engine family was different. AMC, same as GM for the most part.

Yes, the hot-start was a problem. And that backfire killed many a power valve on Holleys.

Here's another pic:

[85lebaront2]

Yes, the hot-start was a problem. And that backfire killed many a power valve on Holleys.

Here's another pic:

Ok, on the front of the air horn, the little "dome" on the casting with a plugged hole in the side, that is the anti-afterburn system, it is a spring loaded ball with an air bleed to over lean the idle circuits on closed throttle to prevent afterburning in the exhaust system, the coast down popping you could get due to unburned fuel in the muffler.

BTW, that is a TSB replacement carb, your Bee originally had a Holley 4160 on it and if you think the 4180 that Ford put on the 460s was a POS, it was way better than the Chrysler designed Holley on the 1968-1970 big blocks.

[Gary Lewis]

Ok, on the front of the air horn, the little "dome" on the casting with a plugged hole in the side, that is the anti-afterburn system, it is a spring loaded ball with an air bleed to over lean the idle circuits on closed throttle to prevent afterburning in the exhaust system, the coast down popping you could get due to unburned fuel in the muffler.

BTW, that is a TSB replacement carb, your Bee originally had a Holley 4160 on it and if you think the 4180 that Ford put on the 460s was a POS, it was way better than the Chrysler designed Holley on the 1968-1970 big blocks.

Actually, there were two carbs for the Bee in '69. The "real" 335 HP Bee's got that AVS, and the 330 HP Bee's got the Holley. I've confirmed that with a lot of research, but it isn't a very well known fact.

My first Bee, new from the factory in May of '69, had the Holley. And you are absolutely right about it being a piece of junk! It was awful, and it was my first Holley, which might explain my lack of love thereof. I was raised with Carters and they were bullet-proof. But that Holley gave me absolutely no end of fits, with a warped main body, blowing power valves, and jetted so lean that it wouldn't accelerate w/o opening the power valve - although that was not Holley's fault.

I thought all Bee's had the Holley until I looked at the factory shop manual, which I have here before me. It says the 383's got the AVS and doesn't even have a section for the 4bbl Holley. But, mine had one the day it rolled out of the factory!

That was a serious point of confusion until one day I was talking with Tony of Tony's Parts the MOPAR guru in lower, slower Delaware - your backyard. I told him of my conundrum and he said "Your engine was turquose and you had A/C and an automatic tranny - right?" Yep, how'd you know? He said "You had the run-of-the-mill 330 HP 383, which they put in the Bee if you ordered A/C and an auto. And it came with the Holley. The 335 HP 383 came with the AVS and was orange." And, that made sense because my Bee said "383 4bbl" on the side, but others said "383 Magnum", which the Bee I currently have says.

Well, that answered the question, but I wasn't really convinced - until I went to the All-Chrysler meet at Carlisle. There was a 1960 Bee survivor that said "383 4bbl" on the side. I asked the owner what carb it had and he said a Carter, but that it originally came with a !@#% Holley, which he had on the shelf. He'd had no end of problems, and finally put a Carter on so he could drive it.

Anyway, the bottom line is that this AVS isn't something I want to run given its emissions "tuning", some of which may not be easily reversed. Right?

[85lebaront2]

Actually, there were two carbs for the Bee in '69. The "real" 335 HP Bee's got that AVS, and the 330 HP Bee's got the Holley. I've confirmed that with a lot of research, but it isn't a very well known fact.

My first Bee, new from the factory in May of '69, had the Holley. And you are absolutely right about it being a piece of junk! It was awful, and it was my first Holley, which might explain my lack of love thereof. I was raised with Carters and they were bullet-proof. But that Holley gave me absolutely no end of fits, with a warped main body, blowing power valves, and jetted so lean that it wouldn't accelerate w/o opening the power valve - although that was not Holley's fault.

I thought all Bee's had the Holley until I looked at the factory shop manual, which I have here before me. It says the 383's got the AVS and doesn't even have a section for the 4bbl Holley. But, mine had one the day it rolled out of the factory!

That was a serious point of confusion until one day I was talking with Tony of Tony's Parts the MOPAR guru in lower, slower Delaware - your backyard. I told him of my conundrum and he said "Your engine was turquose and you had A/C and an automatic tranny - right?" Yep, how'd you know? He said "You had the run-of-the-mill 330 HP 383, which they put in the Bee if you ordered A/C and an auto. And it came with the Holley. The 335 HP 383 came with the AVS and was orange." And, that made sense because my Bee said "383 4bbl" on the side, but others said "383 Magnum", which the Bee I currently have says.

Well, that answered the question, but I wasn't really convinced - until I went to the All-Chrysler meet at Carlisle. There was a 1960 Bee survivor that said "383 4bbl" on the side. I asked the owner what carb it had and he said a Carter, but that it originally came with a !@#% Holley, which he had on the shelf. He'd had no end of problems, and finally put a Carter on so he could drive it.

Anyway, the bottom line is that this AVS isn't something I want to run given its emissions "tuning", some of which may not be easily reversed. Right?

Gary, the problems with the Chrysler Holley were primarily, a redesigned primary metering block and the extremely high engine temperatures the Chryslers had. The latter caused the secondary metering body (plate style) to warp so the bottom corners where the lower portion of the idle circuit feed ran on normal Holleys would lift away from the thin rubber coated paper gasket and allow straight gas into the idle circuits, we used to be able to pull the top of the air filter and look down and see the gas bubbling and boiling as it came out of the slots just above the throttle plates. Holley provided a kit to correct that issue, it had a redesigned metering body with the bottom corners cut off and a different plate with instructions to install the new full coverage rubber coated gasket first, then the new plate, then the normal cork/rubber gasket followed by the metering body. This allowed for some warping of the metering body, but would keep it sealed. I used to take the old ones, lay them face up across a big vice and use a brass hammer to flatten them!

On the primary side, the metering block would warp some, bigger issue was Chrysler's specified transition system, a small fuel feed in the lower side of the primary venturiis, this was uncovered by the throttle plates at roughly 1/3 open to help get fuel into the engine before the main nozzles were fully feeding. The other thing, they were very sensitive to fuel level, if it wasn't damn near to flooding level, they would stumble, backfire and cut off, or set the damn air filter on fire.

It wasn't just Holleys either, the 383 2 barrels with either the Stromberg WWC or the Carter BBD 1 1/2" were horrible for warping the air horn, the resulting pressure differential at high throttle would pull raw fuel out of the bowl and foul the plugs, the resulting hot start backfires didn't help and could also result in a crispy critter. Carter provided a 1/4" piece of bar with two long screws and a built in air filter stud to install, and instructions on straightening the air horn. Problem on both carbs was over-tightening the air cleaner wing nut. I put some double 1/4-20 nuts on a few customers cars who were having problems with over zealous pump jockeys doing the underhood checks and giving the air cleaner nut a twist to make sure it was tight.