Edelbrock 1406 vs. Qjet

[sierrablue]

Ok, so right now I have the 1406 on it, all dialed in, with a non-open adapter (it's has the spread bore on the bottom and square on top vs. being a just a hole sealing off the borders/bolting to both) to the spread bore intake, so I'm pretty happy with the setup. My concern is next year, dealing with altitude.

Now, doing some reading, the 1406 SHOULD be fine with altitude changes, as the metering rods adjust as vacuum changes. There has been indication that worst case you have to go to some leaner rods, and the way it's tuned, I can do that w/o changing the jets (it's on the middle set of rods for its jets), so that wouldn't be bad. At WOT, the Edelbrock sends the vacuum gauge to 0 and pulls harder than the Qjet, which still had 1-2" Hg indicated (which is weird considering that the Edelbrock is supposed to flow ~150 cfm less than the Qjet).

On the other hand, the Qjet has smaller primaries, making for better metering and thus improved mileage and altitude adjustment. It needs cleaned (sediment in the bottom; pretty sure that's why it was running poorly before I put the 1406 back on), and the throttle plate rods need bushings to be put around them.

At this point I'm leaning towards the Edelbrock, because it's cheaper and you're more likely to find parts in the case that something goes wrong. What do you guys think/does anybody have any experience w/both in the mountains?

I know, fuel injection is the way to go, but $$$$$. Thanks guys!

Edit:
To help with context, this is a DD Wagoneer, and still will be there. 90+% of its use will be on the street, any time of the year. Most hard-core trail stuff I do is on a mountain bike, so it shouldn't be seeing anything too wild. I plan to keep the white walls and stock height, so it's not going anywhere a stock Wrangler wouldn't go.

[tgreese]

I would choose the Quadrajet. Its reputation precedes it, and it seems more fun and interesting than the AFB clone. (I think it's an AFB clone...)

Learning to tune a Quadrajet seems like an interesting but archaic skill. Supposedly it's different...

[Stuka]

If the QuadraJet is brand new, then it would be the better offroad carb. If its an old used one, skip it. They tend to warp and leak.

The 1406 is not as good at steep angles as a QuadraJet due to the side hung floats. But it is a lot better on the street.

I ran a 1406 in my Cherokee. I lived at 2500ft, and I worked at 5000ft. And the trails here are 6000-8000ft in most cases. It did pretty well without me having to mess with it. I ran the offroad kit in it, and you can do the fuel hose mod for the rear channel. Also, setting the floats lower helps with inclines.

But if buying new, I would go with a truck avenger over both. Its the best offroad carb out there.

[sierrablue]

I would choose the Quadrajet. Its reputation precedes it, and it seems more fun and interesting than the AFB clone. (I think it's an AFB clone...)

Learning to tune a Quadrajet seems like an interesting but archaic skill. Supposedly it's different...

Yeah the 1406 is an AFB clone.

The Qjets aren't all that hard to tune, at least not on a combination that came from the factory with a Qjet. If you didn't have the right rods/springs or know for sure which to use, I could see it being more difficult...still not really sure why it's any harder than getting a 1406 dialed in.

Though it would be nice to get the secondaries dialed in so my vacuum goes to 0 at WOT...I suspect I'll be giving it a lot more throttle with less O2 in the air...but then maybe things were starting to get plugged up when I checked it and if I clean it and put it back together it'll be fine.

[sierrablue]

If the QuadraJet is brand new, then it would be the better offroad carb. If its an old used one, skip it. They tend to warp and leak.

The 1406 is not as good at steep angles as a QuadraJet due to the side hung floats. But it is a lot better on the street.

I ran a 1406 in my Cherokee. I lived at 2500ft, and I worked at 5000ft. And the trails here are 6000-8000ft in most cases. It did pretty well without me having to mess with it. I ran the offroad kit in it, and you can do the fuel hose mod for the rear channel. Also, setting the floats lower helps with inclines.

But if buying new, I would go with a truck avenger over both. Its the best offroad carb out there.

The off-roading for this Jeep isn't too wild at this point, and I don't anticipate it becoming anything more than the 1406 or Qjet can handle. I plan on keeping the white walls and stock height, so it'll go farther than most street stuff off road but nothing too wild. I'm not going to expect it to go anywhere I wouldn't put a stock Wrangler or anything.

I suppose the throttle plate thing isn't hard to do, just kind of irritating. It's an old Qjet but known to be good (other than the piles of sediment currently sitting in the bottom and the throttle plates).

[OldFarmTruck22]

I always found it difficult to compare carburetor performance when the 2 carbs were used items, with problems. The comparison is just too problematic unless you KNOW that each carb is 100% perfect without leaks. That's really the starting point of any comparison. Throttle shaft leaks, warped plates, clogged passages, etc, make for a 'chasing your tail' experience.
I like the 1406 for the 360. You have to make sure to use the proper manifold spacer depending on if you are using an Edelbrock aluminum manifold or a factory manifold. Makes a big difference in how it runs.

[sierrablue]

I always found it difficult to compare carburetor performance when the 2 carbs were used items, with problems. The comparison is just too problematic unless you KNOW that each carb is 100% perfect without leaks. That's really the starting point of any comparison. Throttle shaft leaks, warped plates, clogged passages, etc, make for a 'chasing your tail' experience.
I like the 1406 for the 360. You have to make sure to use the proper manifold spacer depending on if you are using an Edelbrock aluminum manifold or a factory manifold. Makes a big difference in how it runs.

I mean, the spacer really just adjusts the low-end torque, more space=more low end torque, but if you make it open and/or shorter/cleaner that generally improves horsepower...right?

[OldFarmTruck22]

That's not all. You must look at the phlenum of the manifold directly below the carb.
Things to look for:
1. Is it a wide open square bore?
2. Is it a 'separated' Left/ Right opening?
3. Is it a 4 hole manifold?
These manifold designs along with the carb itself will dictate the carb spacer you should be using.

[sierrablue]

That's not all. You must look at the phlenum of the manifold directly below the carb.
Things to look for:
1. Is it a wide open square bore?
2. Is it a 'separated' Left/ Right opening?
3. Is it a 4 hole manifold?
These manifold designs along with the carb itself will dictate the carb spacer you should be using.

Sorry. In my mind, it's just a gimme that you want to get all of that lined up so I didn't think about it.

[Mopar_guy]

I would take a Q jet over the Eddy any day but I've also had a lot of experience with them in the 70's thru the 90's. Much sharper throttle response and usually better mileage.The biggest drawback with the Eddy is how easy the gas boils in them during warm weather. In my experience with them, you need at least a 1" phenolic spacer to stop it along with blocking the crossover.

[OldFarmTruck22]

I would take a Q jet over the Eddy any day but I've also had a lot of experience with them in the 70's thru the 90's. Much sharper throttle response and usually better mileage.The biggest drawback with the Eddy is how easy the gas boils in them during warm weather. In my experience with them, you need at least a 1" phenolic spacer to stop it along with blocking the crossover.

Agree with you on the spacer, just make sure you use the correct spacer. Edelbrock does a great job now of mentioning this in their Owners MAnual and Set-up Guide that comes with a new carb. You can also download it online.
Matching the venturi on bottom of carb/top of spacer/bottom of spacer/manifold makes a big difference.

[Stuka]

I always found it difficult to compare carburetor performance when the 2 carbs were used items, with problems. The comparison is just too problematic unless you KNOW that each carb is 100% perfect without leaks. That's really the starting point of any comparison. Throttle shaft leaks, warped plates, clogged passages, etc, make for a 'chasing your tail' experience.
I like the 1406 for the 360. You have to make sure to use the proper manifold spacer depending on if you are using an Edelbrock aluminum manifold or a factory manifold. Makes a big difference in how it runs.

I mean, the spacer really just adjusts the low-end torque, more space=more low end torque, but if you make it open and/or shorter/cleaner that generally improves horsepower...right?

Spacers can actually have a big impact on the entire power band. EngineMasters has done a lot of testing with different types of spacers. The tapered combo is the hands down winner for power. But, they are all aluminum, so they will not insulate heat as much if you have a cast iron intake. Aluminum intakes transfer less heat to the carb.

[OldFarmTruck22]

I always found it difficult to compare carburetor performance when the 2 carbs were used items, with problems. The comparison is just too problematic unless you KNOW that each carb is 100% perfect without leaks. That's really the starting point of any comparison. Throttle shaft leaks, warped plates, clogged passages, etc, make for a 'chasing your tail' experience.
I like the 1406 for the 360. You have to make sure to use the proper manifold spacer depending on if you are using an Edelbrock aluminum manifold or a factory manifold. Makes a big difference in how it runs.

I mean, the spacer really just adjusts the low-end torque, more space=more low end torque, but if you make it open and/or shorter/cleaner that generally improves horsepower...right?

Spacers can actually have a big impact on the entire power band. EngineMasters has done a lot of testing with different types of spacers. The tapered combo is the hands down winner for power. But, they are all aluminum, so they will not insulate heat as much if you have a cast iron intake. Aluminum intakes transfer less heat to the carb.

Absolutely, and a divided manifold intake plenum such as the Edelbrock AMC manifold needs a certain type of spacer when used with a square bore or spreadbore manifold. These guys aren't amateurs like us, they DYNO the crap out of these products to know what works best.

[sierrablue]

C'mon, I know more than TWO people have to have experience/an opinion on this...feel free to put your vote in the pole!

[OldFarmTruck22]

C'mon, I know more than TWO people have to have experience/an opinion on this...feel free to put your vote in the pole!

What more do you want ... the Best of the Best has responded! lol

Quadrajets are very old school caburetors designed for economy on production vehicles from the 60's through the 70's. They had to be hotrodded to accommodate performance and altitude. Now 60 years later, there are carburetors that you can easily tune to fit most any need. My opinion, why make your life more difficult when you don't have to. These boutique quadrajet shops out there will charge you deeply to get the performance you are looking for, compared to out of the box easy tuning with an Edelbrock.

[sierrablue]

C'mon, I know more than TWO people have to have experience/an opinion on this...feel free to put your vote in the pole!

What more do you want ... the Best of the Best has responded! lol

Quadrajets are very old school caburetors designed for economy on production vehicles from the 60's through the 70's. They had to be hotrodded to accommodate performance and altitude. Now 60 years later, there are carburetors that you can easily tune to fit most any need. My opinion, why make your life more difficult when you don't have to. These boutique quadrajet shops out there will charge you deeply to get the performance you are looking for, compared to out of the box easy tuning with an Edelbrock.

Thanks! Ig I don't totally agree on the complexity (I already have the right rods+springs--these Buick 350s came from the factory with a Qjet on the 4-barrel Buicks), so it's really not any harder to tune than the Edelbrock. And I thought the whole point of the Qjet was that the smaller primaries made for better metering (thus better mileage and altitude/temperature compensation), and the massive secondaries were there for when you need to go.

Also I'm stuck back in my 12-13 mpg hole with the Edelbrock--no matter how I drive it, it's 12-13. With the Qjet I got 16 on winter gas once, 14 regularly. And that was before I had a vacuum gauge. It just bugs me I guess, knowing it could do so much better for mileage.

I do agree 100% on the cost of working on the Qjets tho. It's so stupid--for the price of simply fixing the one that I have, I could just buy a brand new Edelbrock 1900 series (Edelbrock makes a brand new Qjet). Maybe I should get some stuff sold and I can just buy one of those...

I also wonder about calling Edelbrock and seeing if I can just buy the bottom piece (for the throttle plates), and bolt that onto the existing Qjet. That would solve a lot of my problems I think.

[tgreese]

... Quadrajets are very old school caburetors designed for economy on production vehicles from the 60's through the 70's. They had to be hotrodded to accommodate performance and altitude. Now 60 years later, there are carburetors that you can easily tune to fit most any need. My opinion, why make your life more difficult when you don't have to. These boutique quadrajet shops out there will charge you deeply to get the performance you are looking for, compared to out of the box easy tuning with an Edelbrock.

As I recall, the Quadrajet was highly favored by Wagoneer owners a couple of decades ago. It was renowned as an excellent trail carburetor, since it would run up/down and on side hills, and keep running over rough terrain. It and the Motorcraft 2V were popular for this reason.

Certainly the QJet cores were more available and in better shape back then. Today there are newly manufactured carbs that compete, and the EFI kits are very popular. To me, EFI is simpler, more reliable, has better performance and works better on the trail than any carburetor. I'd guess the cost is about 3x what you'd pay for a new carburetor today, and about twice what you'd pay for the new carb and an aftermarket 4V manifold. Seems hard to justify either the old QJet or a new AFB clone, unless you just want to play with an archaic mechanico-vacuum-powered device.

[sierrablue]

... Quadrajets are very old school caburetors designed for economy on production vehicles from the 60's through the 70's. They had to be hotrodded to accommodate performance and altitude. Now 60 years later, there are carburetors that you can easily tune to fit most any need. My opinion, why make your life more difficult when you don't have to. These boutique quadrajet shops out there will charge you deeply to get the performance you are looking for, compared to out of the box easy tuning with an Edelbrock.

As I recall, the Quadrajet was highly favored by Wagoneer owners a couple of decades ago. It was renowned as an excellent trail carburetor, since it would run up/down and on side hills, and keep running over rough terrain. It and the Motorcraft 2V were popular for this reason.

Certainly the QJet cores were more available and in better shape back then. Today there are newly manufactured carbs that compete, and the EFI kits are very popular. To me, EFI is simpler, more reliable, has better performance and works better on the trail than any carburetor. I'd guess the cost is about 3x what you'd pay for a new carburetor today, and about twice what you'd pay for the new carb and an aftermarket 4V manifold. Seems hard to justify either the old QJet or a new AFB clone, unless you just want to play with an archaic mechanico-vacuum-powered device.

That's all fair--assuming you don't want a better intake with your fuel injection. And cost is an issue too.

If I had the money to do it RIGHT (other than an EV conversion, which would get me 600 lb ft of torque instantly, at sea level or on the moon), I'd get the multiport kit from T/A Performance, and an in tank pump from BJ's, and be done. As it is that's not really an option.

[akguy09]

C'mon, I know more than TWO people have to have experience/an opinion on this...feel free to put your vote in the pole!

You only gave 2 choices.

I wouldn't use an Edlebrock at all when I can use a Holley

Now....which oil should I use.....

[tgreese]

Multiport - interesting. Please correct me if I'm wrong, but my understanding: multiport is mostly about emissions. You need quite a lot of engineering and testing to make a multiport implementation comparable to OEM multiport engines. Home-brew multiport does not do any better than throttle body.