Carburetors - Gary's Musings

[Gary Lewis]

I will rise to your bait, and raise you some, Weber is by far the absolute best carburetor, however, a Skinner Union is as simple a piece of machinery as can possibly be, only 2 moving parts, no accelerator pump or choke (strangler as the Brits would say).

You are getting slow in your old age. 😈

So, what’s the most complex carb? The Q-Jet? Or the VV?

[ArdWrknTrk]

How much for that Thunder 650?

Where's it shipping from?

When is it available?

It will be available as soon as my new engine goes in with Its 750. }>

Idk, what do you think is fair?

I paid $128.50, bought an ~$30 rebuild kit, a new choke element and an $89!!!!! dual feed fuel line.

Spent a day going through it.

The 1826 seems a good match for my 460 but a little short of wind on top.

[85lebaront2]

You are getting slow in your old age. 😈

So, what’s the most complex carb? The Q-Jet? Or the VV?

I was eating dinner, most complex, toss up between the last of the Rochester 4GCs for Oldsmobile, 7 float adjustments, primary heel and toe, drop and vacuum assist on the primary and the Motorcraft 4300D, the Quadrajet wanna-be, two inlet needles, long double pontoon articulated float (they stole that from carter WCDs on Rambler 6s because they sat sideways) and the air valve system with the inverted needles for air bleed on the secondaries. The VV is nothing more complex than downdraft 2bbl Zenith Stromberg. Just takes very sensitive vacuum gauges, like 0-1" HG to set the diaphragm. The main mixture is non-adjustable as built, but can be set if you know how. I put a non-feedback one on a 312 Y-block and got 25 mpg out of it.

[Edward Michael]

It will be available as soon as my new engine goes in with Its 750. }>

Idk, what do you think is fair?

I paid $128.50, bought an ~$30 rebuild kit, a new choke element and an $89!!!!! dual feed fuel line.

Spent a day going through it.

The 1826 seems a good match for my 460 but a little short of wind on top.

Summit is saying the eddy 1826 is specific to off-road and will not perform well for street use.

Seems that in our situation we are buying off the shelf.

Probably the 1406 as we are running stock engine and not sure we need adjustable secondaries.

Thank you for the consideration on your 1826.

Still more research on the fuel line as we are not interested in running inferior product and rerunning

again later. The ethanol gas law does not look like its changing and I am more into running the tightest

spec and not dealing with it later or even having it in a trouble shooting situation.

Quick example:

Ethanol resistant grade: 25ft is $25

Alcohol/biodiesel grade: 25ft is $75

Cheap investment for the fuel situation here.

[Gary Lewis]

I was eating dinner, most complex, toss up between the last of the Rochester 4GCs for Oldsmobile, 7 float adjustments, primary heel and toe, drop and vacuum assist on the primary and the Motorcraft 4300D, the Quadrajet wanna-be, two inlet needles, long double pontoon articulated float (they stole that from carter WCDs on Rambler 6s because they sat sideways) and the air valve system with the inverted needles for air bleed on the secondaries. The VV is nothing more complex than downdraft 2bbl Zenith Stromberg. Just takes very sensitive vacuum gauges, like 0-1" HG to set the diaphragm. The main mixture is non-adjustable as built, but can be set if you know how. I put a non-feedback one on a 312 Y-block and got 25 mpg out of it.

I haven’t really played with the 4GC, much less the Olds one. I jumped from a Will Carter Four Barrel to an Aluminum Four Barrel. But played extensively with Q-Jets as well. Never worked on a VV for that matter, although I have worked on many bike carbs with the same principle.

[ArdWrknTrk]

Summit is saying the eddy 1826 is specific to off-road and will not perform well for street use.

Seems that in our situation we are buying off the shelf.

Probably the 1406 as we are running stock engine and not sure we need adjustable secondaries.

Thank you for the consideration on your 1826.

Still more research on the fuel line as we are not interested in running inferior product and rerunning

again later. The ethanol gas law does not look like its changing and I am more into running the tightest

spec and not dealing with it later or even having it in a trouble shooting situation.

Quick example:

Ethanol resistant grade: 25ft is $25

Alcohol/biodiesel grade: 25ft is $75

Cheap investment for the fuel situation here.

The only real difference in AVS carbs is the jetting they come with.

"Street" vs "off road" is the difference between jetting for 'economy' or 'power' on the Edelbrock charts.

I'm fairly sure Gary has been down this road, and has the documentation.

Maybe you should consider marine fuel hose.

That stuff is tough as nails and has a near inpenatrable liner.

[Gary Lewis]

The only real difference in AVS carbs is the jetting they come with.

"Street" vs "off road" is the difference between jetting for 'economy' or 'power' on the Edelbrock charts.

I'm fairly sure Gary has been down this road, and has the documentation.

Maybe you should consider marine fuel hose.

That stuff is tough as nails and has a near inpenatrable liner.

Jim is right, with one minor exception - the inlet needles. The 1826 comes with spring-loaded needles where the 1825 doesn’t. Ebedbrock says it “Includes spring-loaded needles and seats for superior fuel control in off-road terrain.” But, if my memory serves me, back in the day Carter ran spring-loaded inlet needles on many street vehicles. Perhaps Bill can refresh my memory?

Of course Jim rebuilt the carb, as others may have earlier. Jim, did you put sprin-loaded needles in? Those are easily changed.

As for the calibration, Jim is spot-on - the 1826 is calibrated slightly richer at part-throttle. You can see the jetting on Edelbrock’s site, but the two carbs have the same primary and secondary jets as well as the same step-up spring. The only thing that is different is that the 1826 has a metering rod with a smaller cruise size, so that means it will allow a bit more fuel to flow in the cruise mode.

Personally, I wouldn’t at all be concerned about running the 1826 on the street. As said, the inlet needles are easily changed, if they haven’t already been. And the cruise enrichment might be a bonus when running s smaller carb on a big engine.

[85lebaront2]

Jim is right, with one minor exception - the inlet needles. The 1826 comes with spring-loaded needles where the 1825 doesn’t. Ebedbrock says it “Includes spring-loaded needles and seats for superior fuel control in off-road terrain.” But, if my memory serves me, back in the day Carter ran spring-loaded inlet needles on many street vehicles. Perhaps Bill can refresh my memory?

Of course Jim rebuilt the carb, as others may have earlier. Jim, did you put sprin-loaded needles in? Those are easily changed.

As for the calibration, Jim is spot-on - the 1826 is calibrated slightly richer at part-throttle. You can see the jetting on Edelbrock’s site, but the two carbs have the same primary and secondary jets as well as the same step-up spring. The only thing that is different is that the 1826 has a metering rod with a smaller cruise size, so that means it will allow a bit more fuel to flow in the cruise mode.

Personally, I wouldn’t at all be concerned about running the 1826 on the street. As said, the inlet needles are easily changed, if they haven’t already been. And the cruise enrichment might be a bonus when running s smaller carb on a big engine.

I seem to recall in my Carter strip kit, there were 3 different size inlet seats and all could use the spring loaded needles. There were also different strength step up (correct term from Carter for the non-mechanical metering system) rod springs to change the vacuum level at which the rod would lift. The absolute best setup was the one Chrysler used on their AFB and AVS carbs, it was a two stage system, and required two changes, neither of which involved different castings. First, the top covers over the pistons had to be raised so the first stage spring and the longer second stage spring could raise the piston higher, the second was the main jets were made taller so the metering location was where the relocated steps (now 3) were. The actual rods were the same length, just had 3 steps instead of 2. The original design had cruise and power steps, the updated design for Chrysler was cruise, moderate load and power. This was to give a smoother transition from cruise to power and allowed leaner cruise jetting.

[Gary Lewis]

I seem to recall in my Carter strip kit, there were 3 different size inlet seats and all could use the spring loaded needles. There were also different strength step up (correct term from Carter for the non-mechanical metering system) rod springs to change the vacuum level at which the rod would lift. The absolute best setup was the one Chrysler used on their AFB and AVS carbs, it was a two stage system, and required two changes, neither of which involved different castings. First, the top covers over the pistons had to be raised so the first stage spring and the longer second stage spring could raise the piston higher, the second was the main jets were made taller so the metering location was where the relocated steps (now 3) were. The actual rods were the same length, just had 3 steps instead of 2. The original design had cruise and power steps, the updated design for Chrysler was cruise, moderate load and power. This was to give a smoother transition from cruise to power and allowed leaner cruise jetting.

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.

[ArdWrknTrk]

Jim is right, with one minor exception - the inlet needles. The 1826 comes with spring-loaded needles where the 1825 doesn’t. Ebedbrock says it “Includes spring-loaded needles and seats for superior fuel control in off-road terrain.” But, if my memory serves me, back in the day Carter ran spring-loaded inlet needles on many street vehicles. Perhaps Bill can refresh my memory?

Of course Jim rebuilt the carb, as others may have earlier. Jim, did you put sprin-loaded needles in? Those are easily changed.

As for the calibration, Jim is spot-on - the 1826 is calibrated slightly richer at part-throttle. You can see the jetting on Edelbrock’s site, but the two carbs have the same primary and secondary jets as well as the same step-up spring. The only thing that is different is that the 1826 has a metering rod with a smaller cruise size, so that means it will allow a bit more fuel to flow in the cruise mode.

Personally, I wouldn’t at all be concerned about running the 1826 on the street. As said, the inlet needles are easily changed, if they haven’t already been. And the cruise enrichment might be a bonus when running s smaller carb on a big engine.

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.