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It's a shame that carburetors are becoming a thing of the past. These components can do everything a computerized fuel injection system can, even without the sensors. For this reason, many car enthusiasts prefer to use carburetors because it can be easier to adjust for the air and fuel mixture you’re after.
People also prefer carburetors because replacing or rebuilding one can be cheaper than installing a fuel injection system on an engine that's not designed for it. You're in the right place, regardless of why you need a new carburetor. Read on to learn more about the range of 600-650 CFM carburetors at JEGS to see which one’s the right fit for you.
What Is a Carburetor and How Does it Work?
Carburetors are parts that you usually find in older, less complex vehicles. They were prominent before fuel injection systems, but many people still prefer them today because they are easy to tune. A carburetor is a fuel meter with an air "butterfly" valve and fuel jets which controls the amount of air and fuel entering an engine as well as the engine's speed. There are also other components, such as idle air and idle speed screws, which allow you to adjust the mixture of fuel and air entering the cylinders or the idle rpm of your engine.
Carburetors combine fuel and air into a mixture that an engine can use for combustion. First, air enters the carburetor from the air intake or air cleaner after flowing through an air filter. From there, the air flows into the venturi, which is designed to optimize the atomization of fuel and air in the carburetor. Entering this region causes the air pressure to drop, pulling fuel in from the squirters or discharge tube through suction caused by engine vacuum. Then, the mixture flows into the cylinders and is ignited to create combustion.
The amount of air and fuel in the cylinders will vary based on the throttle. So, if you floor it, the throttle will cause more fuel and air to be introduced from the carburetor to the engine.
How Can You Tell You Need to Change A Carb?
Carburetors don't last forever, and while they can last for most of the lifespan of a vehicle, you have to rebuild or replace them every once in a while. Expect to replace or rebuild your carburetor every 100,000 miles for optimal performance. Learn about the signs that it's time to replace your carburetor below.
Rough Idle
A signature tells that it's time to replace your carburetor if you’re having a rough idle and won’t smooth out. If you start your engine and notice that the RPMs are fluctuating too much, it's a sign that too much fuel or air is in the mixture, which is impacting combustion. While this can be the most prominent during idle, it can also happen as you accelerate and come back to a stop, which may even result in the engine stalling. Some other signs of a rough idle include the engine shaking, making strange noises, or sputtering.
Problems with Acceleration
Noticing an issue with your engine’s acceleration? And has it come on suddenly? If so, there's a good chance that your carburetor is in need of repair or replacement. Typically, this happens when the fuel mixture is too lean (not enough fuel and too much air) and it results in less power. It may even out once you accelerate but if you're having problems merging onto the highway it could be your carburetor.
Trouble Starting Your Engine
When your carburetor fails, you might have trouble starting your engine. If it's not working properly, you don't have the correct fuel needed to start the combustion process. Unfortunately, this results in problems getting your engine started.
Black Smoke Coming from Your Exhaust
When you're driving, you should never see thick black smoke coming from your exhaust. If you see black smoke it means that your engine is running a rich fuel mixture; too much fuel is getting into the cylinders. Unfortunately, this means that something is wrong, potentially with your carburetor, and causing it to function this way. It’s probably got you thinking about changing the carb with a new one, and we’ve got popular 600-650 CFM carbs for small block V8 engines in droves.
Best 600-650 CFM Options
JEGS has more performance parts than most online, and there are roughly a hundred 600 to 650 CFM carburetors available to choose from. It can be a bit confusing to figure out which one works best for your car, and honestly, it’s a great idea to check out our carburetor size calculator first to make sure you’re looking at the right range, and to help you select the perfect carb for your setup.
If you’ve already figured out the sizing, we’ve got some great suggestions for you. Check out these five top performers in one of the most common carb ranges out there.
Holley 600CFM Aluminum Street Carburetor
With a name like Holley, you know the manufacturing quality is there. This option is meant for many common models, and it’s manufactured out of aluminum not just for the long-lasting shine, but because it shaves some weight off your vehicle compared to zinc models. Our Holley 600CFM Aluminum Street Carburetor is equipped with electric choke for simple operation, has vacuum secondaries for daily use, and is perfect for stock or mildly modified street cars. Be aware that it’s not compatible with Chrysler AODs, though.
Demon Carburetion 650CFM Road Demon Carburetor
A four-barrel beast, to be sure. The 650CFM Road Demon Carburetor makes short work of installation with an electric choke and mechanical secondaries, so it’s bolt-on-ready. Made of aluminum and polished to a shiny gloss, the style goes a long way for show cars that are meant to perform too. It’s best used – you can probably guess – at WOT. And luckily, there are provisions for GM 700R4/2004R, Ford, and Chrysler automatic transmission kickdowns.
Edelbrock Performer Series 600CFM EGR Carburetor Kit
Can’t get away from those pesky emissions standards? The Edelbrock Performer Series 600CFM Carburetor has EGR options, timed vacuum ports, and a fuel vapor outlet. The all-aluminum structure resists warpage and looks great too, and it’s capable of running gasohol and other non-pump blends.
Quick Fuel 600CFM Black Diamond 1957 Carburetor
Prefer something a little darker under the hood? You’ve got it with the Quick Fuel Black Diamond 1957 Carburetor. Changeable jets and a secondary metering plate make it very tunable; it has throttle levers for 700R4 and Ford automatic transmission kickdowns, plus you can mount a bracket for Chrysler linkage too. But we keep returning to the black PTFE coating from NitroPlate… very cool.
FST Performance Forged RT 4 Barrel 600CFM Carburetor
For a slightly more budget-based option, let’s check out the FST Performance Forged RT 4 Barrel Carburetor with Vacuum Secondary. It’s another great 600CFM carb with all the standard fixings – vacuum secondaries, electric choke, that shiny polished aluminum finish, and a side-hung float. Nothing super fancy, but it gets the job done right and at a great price.
Ready to buy? JEGS has the right carburetor choices for your car, whether for the street or the track. And if you need expert advice, our in-house team is always ready to help.
