Chevy Corvette Forum banner

1 - 14 of 14 Posts

·
Registered
Joined
·
102 Posts
Discussion Starter #1
I have a small block L82 with the factory manifold that I want to keep. No headers, I just want a good performing carburetor that will fit the factory manifold. Any luck.
Thanks,
Matt
 

·
Registered
Joined
·
523 Posts
there is nothing wrong with your factory Quadrajet- a good rebuild, some tuning, and it will perform as well as any aftermarket carb with lots less hassle.
If you don't want to take on a rebuild yourself, I've heard there are several really good Q-Jet guys around.
 

·
Premium Member
Joined
·
9,048 Posts
I m with Tim, a good Q-jet is hard to beat on a stock or mild motor.. it will equal performance and usually surpass economy of any aftermarket carb... you can get a rebuilt .
 

·
Registered
Joined
·
9,695 Posts
I have a small block L82 with the factory manifold that I want to keep. No headers, I just want a good performing carburetor that will fit the factory manifold. Any luck.
Thanks,
Matt

The QuadraJet is an excellent (but often misunderstood) carburetor. As it has an "air valve secondary" design it'll work well on everything from 6-cylinder up to the big 454" engines as it'll only flow what's needed to feed the engine. They are very easy to rebuild and every part is readily available through the internet. Whether you have a totally stock engine or a highly modified engine the QuadraJet will do it all. As they have very small primaries they mix the air and fuel well and provide excellent gas mileage. If you prefer Holley carburetors Holley makes a QuadraJet replacement that will flow around 650 cfm (about 130 cfm less than the QuadraJet). But anytime you change brands of carburetors you will certainly create more problems as far as the choke operation and the fuel line connection goes. QuadraJet carburetors use fixed jets and metering rods (available in many different sizes) whereas Holley uses jets of different flow rates. And Holley also uses a vacuum operated "power valve". Both systems operate equally as well but the Holley system uses less parts. I think you would be far better off running your QuadraJet as it is already equipped with the right parts to work on your manifold.
 

·
Registered
Joined
·
32 Posts
I run an Edelbrock 750 (1407) on my '73 L-82, but then mine isn't stock. I would say in your case, stay with the Quadrajet. Tuned properly, it'll run excellant and they sound awesome when those big back two open.
 

·
Registered
Joined
·
102 Posts
Discussion Starter #8
Reply to all

Thanks for all your help. The manifold is stock but the previous owner put an edelbrock carb on it. From what Im hearing from all of you is good news. I will look into buying the factory carb somewere, it seems like the way to go. What do you think?
 

·
Registered
Joined
·
210 Posts
The Q-Jets are good carbs, that's if you have one. Good, working, unmolested Q-Jets are getting hard to find. Many of them have been beat up pretty badly and commercial rebuilt units can be scary. If you can find a good core, you can try rebuilding it yourself or send it out to one of the dependable vendors. The trick is trying to find that elusive "good core". I found one at a local Vette restoration shop who sells new and used parts. If you have an original spread-bore manifold, and you have an Edelbrock carb, is there a carb adapter between the two?
 

·
Registered
Joined
·
9,695 Posts
Overhauling A QuadraJet

There's nothing hard about overhauling a QuadraJet. The late computer controlled versions take a little more time but they're still very easy. I have overhauled dozens of them in my lifetime and I've never had any problem with any of them. Once they're cleaned up it only takes about 30 minutes to reassemble. The choke adjustment must be made when the engine is cold so if you don't get it exactly right the first time you wait until the following morning to fine tune it.
 

·
Registered
Joined
·
102 Posts
Discussion Starter #12
Thanks for the advise...

Your help and advise from everyone is helpful. I will see how it runs after the re-fresh and take it from there. I spoke to someone at Summit and he said the one I have is a Quadrajet made by Eddlebrock. Go fugure...
 

·
Registered
Joined
·
102 Posts
Discussion Starter #13
I just had it re-built and it has a spread-bore, there was a hard plastic adaptor that I put between the carb and manifold. Is there a number of turns on both the air and fuel mixing valve screws. I want to adjust them myself.
Thanks,
Matt
 

·
Registered
Joined
·
1,423 Posts
I just had it re-built and it has a spread-bore, there was a hard plastic adaptor that I put between the carb and manifold. Is there a number of turns on both the air and fuel mixing valve screws. I want to adjust them myself.
Thanks,
Matt
The adapter is a phenolic spacer to insulate the carb against heat from the manifold.
But to adjust the carb, gently seat both mixture screws then turn each mixture screw out 1-1/2 to 2 turns. Attach a vacuum gauge to a manifold vac. source. ,start the car and warm up to operating temp., adjust idle speed to specified RPM in park. Turn idle screws, one at a time, either in or out and try to obtain the highest vacuum reading. Then RE-adjust idle speed and take it for a ride. :thumbsup3:
 
1 - 14 of 14 Posts
Top