shake-N-bake

So I just passed my 1 year anniversary with my car, and I've had an absolute blast with it so far. However, I still have yet to experience a full-power, no-bog run up through the gears. The Q-Jet on my car bogs anywhere past about 3500 rpm, and I'm ready for a change. I know many of you will tell me to get my Q-Jet rebuilt and/or have it tuned. But I've got my eye on an Edelbrock carb to sit atop my Edelbrock #2101 manifold. Now I know a lot more about carburetors than I used to, but probably nothing compared to all y'all. I'm looking at a #1406 (http://store.edelbrock.com/9906.aspx) which has been recommended, but I only have one reservation: it says on the site. As you might have gleaned from above, I'm looking for this carburetor to raise my Smiles per gallon, any benefit to my miles per gallon would be nice, but it's not what I'm looking for. Could any of you with more experience speak to my fear? I looked at a #1407 which says "Calibrated for Street Performance" - now we're talkin'! But I hear that I don't need the extra 150 CFM on my mildly upgraded engine. Your thoughts please and thank you.

scottyp99

The 1405 is the 600 cfm carb jetted for performance, but it has a manual choke. Look at this link, and look at the jetting for the 1405 and the 1406. That's about the only difference between the two carbs. Buy the 1406 and tune it, they come with a booklet that tells you how.

http://www.edelbrock.com/automotive_...erformer.shtml


Scott

shake-N-bake

That sounds fair enough. Now, I'll have to get a new air cleaner no? I'm looking at buying the carb from Summit Racing, and they've got several that look good. I don't really like my current one, but it has an outlet to the valve cover (as seen below) that I'm wondering if I need to keep?

qwank

most likely your intake is a spread bore design, you will need a squarebore adapter to fit the Edelbrock, or a squarebore intake, which is what I would recommend.

My opnion is: If you REALLY need to get rid of the Q-jet, go with a Holly

shake-N-bake

I looked up my manifold on the Edelbrock website and they say the I think that means a #1406 will fit on there no problem?

And as far as a Holley goes, I have heard the same from other people, but I like the idea of a matched series carburetor and intake manifold. Is this really a non-issue though?

SmokedTires

Pull your air cleaner and see if you have a spread bore or square bore carb, you don't want to buy the wrong one if you're hoping to just bolt it on when it arrives

If your engine is stock, the 600cfm will probably be fine and help with throttle response.

WTFizzit

The ED carbs are pretty good "set 'em and forget 'em" units, pretty stable once tuned. I've read somewhere that they are a bit sensitive to strong g-forces, but don't take that as gospel.

You may want to consider the 1806 AVS (650 cfm) carb, more tunable than the Performer series. I like the QJets but, unfortunately, they are getting to be a challenge to obtain parts and competent repair services for them. It will be tough to match the economy and performance capabilities that are characteristic of a well tuned QJ.

I have one (ED 1806) on a Holley 300-38 "Contender" manifold in my '73-----with a 1/2" spacer the original air cleaner works just fine. The fuel inlet is located differently and there is no built-in filter so one has to be incorporated. I'd post a pic of my setup but I'm unworthy of the attachment privilege, but pm me with your email address and I'll send it to 'ya.

7T1vette

The Edelbrock 1400 series is a square-bore carb and a re-make of the old AFB carbs from the early 1960's. It's simple, it's cheap, and it won't work on your intake. Spend $15 for a copy of Cliff Ruggles' "How to Work on and Modify the Quadrajet Carburetor". Read it, then spend another $15 for a rebuild kit. Then do what Cliff recommends for your carb.

A mid-rpm bog is either due to the secondary air valve opening too quickly (too much fuel) or not quickly enough (too little fuel). Both are easily corrected with a minor adjustment to the spring rate of the secondary air valve. In any event, if you follow Ruggles' advice, your carb will work fine.

P.S. The 1406 carb is large enough for your engine...unless you decide to upgrade it later. The Q-Jet will be adequate for your engine no matter how many 'hot' parts you throw at it.

shake-N-bake

After doing a little more research, I'm betting that I'm getting bog because my secondary air flap vacuum dampener is no-existent?

This is a picture from a different post. Without a dampener, I hear that the doors slam back and forth which causes the bog. Any thoughts on that?

WTFizzit

In the first post of this thread Shake-N-Bake stated that he is/will be using an Edelbrock 2101 manifold. Correct me if I'm wrong, but isn't the 2101 one of the "split-the-difference" cross between square and spread bore type manifolds? I have no experience with the QJet/Performer combination, but seems like there is potential for less than perfect match.

The Performer and AVS carbs will fit that manifold at least as well as the QJet does, will they not?

If that air cleaner is original to your car you definitely want to keep it.

scottyp99

I think the Edelbrock carb base may be wide enough to seal against the spreadbore 2101 intake. I don't have any personal experience with an Eddy carb, but looking at it, it may be true. I have a holley squarebore on my 2101 spreadbore intake, it uses a thin adapter plate, maybe 1/8" thick. Adapters are frowned upon, but I think that mostly comes from the ones that let you put a spreadbore carb on a squarebore base. Just looking at one makes ya wonder why anybody would think it was a good idea!! I don't think a squarebore carb on a spreadbore intake will lose much in the way of flow into the intake.
You will also need to deal with the fuel line somehow. Not too big of a deal, there are some good solutions out there.

I would definitely recommend staying with the Q-jet, if it is a pre-1975 unit. The post-1975 units are great carbs, but nobody makes primary metering rods for 'em. So, the only way you can tune them for part throttle and cruise is to dis-assemble it and drill holes bigger, plug holes and drill them smaller, and other such non-sense.


Scott

Vette5.5

You're on the right track, but an Edelbrock Performer intake with a properly set up Q-Jet is really the way for the street. I'd also do something about the the air cleaner assembly to hose in fresh air in front of the radiator.

WTFizzit

If that latest pic represents the situation as it is now (vacuum line missing from the distributor vacuum advance can) you may have vacuum leak and ignition timing issues.

madeintheusa

I'm running the 1406 on my wifes i hate that carb. Had one years back and it ran like crap get a good Holley our score yourself a demon before there all gone.

Ben Lurkin

Actually, the eddy afb's WILL fit just fine on that manifold. They have a dual bolt pattern that allows them to do so. They're a pretty good carb too. One reason not to use them on a vette though is they have a passage machined between the L and R flooat bowls. If you corner hard, the fuel will transfer from one side to the other; causing a lean condition. This passage needs plugged if you use this carb. Epoxy works nicely for this. That being said, the qjet is a better carb if you can get the bugs sorted out. Get Lars's paper on tuning them. The book 71 mentions is a good reference as well.

Vette5.5

Q-Jets are a pain, but when set up properly, really nothing on the street can touch them. Can usually tell when a guys running something else, as know he's back there somewhere. Don't confuse street with the strip, as just about anything can easily be set up for a narrow rpm range.

pawpaws toy

I run a #1406 on a Weiand 8004. Crisp throttle response, no loading up, no bogging.

Ganey

Scott
Yes, carb to intake adapter normally means an about 3/4" to 2" adapter (on Corvette, Chevy & GM carbed forums).
As you now the 2101 accepts both spread bore & square bore carbs so no adapter is needed. While I have never had any trouble sealing a Holley square bore to a 2101 w/o any sealer, some add about a 1/16" plate to "help seal". Fine, not an issue.

Primary Jets can be changed in Q-J & used rods are fine.

Mike Ward

Yes, I'd say that would make a big difference.

Ganey

Yes, when the damper is removed, the adj. spring should be tightened a lot.

I have not done it that way.