Whats a good size carburetor for a Chevy 350?
When it comes to selecting the right carburetor size for a Chevy 350 engine, there are a few key factors to consider. The general recommendation is to use a 600 CFM (cubic feet per minute) carburetor, as this size provides a good balance of performance and drivability for most Chevy 350 applications.
Understanding Carburetor Sizing
The carburetor size, measured in CFM, refers to the maximum amount of air the carburetor can flow. A larger carburetor (e.g., 750 CFM) will allow more air and fuel to enter the engine, resulting in increased power output. However, a carburetor that is too large for the engine can cause issues such as poor low-end torque, hesitation, and difficulty in tuning the air-fuel mixture.
For a Chevy 350 engine, a 600 CFM carburetor is generally considered the sweet spot. This size provides enough airflow for most performance upgrades, such as camshafts, headers, and intake manifolds, while still maintaining good drivability and fuel efficiency.
Factors to Consider
When choosing a carburetor size for a Chevy 350, you should also consider the following factors:
- Engine Modifications: If your Chevy 350 has been heavily modified with upgrades like forced induction, larger camshafts, or high-flow cylinder heads, you may need to step up to a larger carburetor, such as a 650 or 750 CFM model.
- Intended Use: If your Chevy 350 is primarily used for street driving, a 600 CFM carburetor is likely the best choice. For dedicated race applications, a larger carburetor may be more appropriate.
- Fuel System Compatibility: Make sure the carburetor you choose is compatible with your fuel system, including the fuel pump and fuel lines.
Ultimately, the best carburetor size for your Chevy 350 will depend on the specific modifications and intended use of your engine. It's always a good idea to consult with a knowledgeable mechanic or engine builder to ensure you select the right carburetor for your setup.
What CFM is a stock quadrajet carb?
Two basic sizes of Quadrajet were produced over the years; 750 and 800 CFM versions. The 800 CFM unit (identified by a slightly larger primary venturi) was relatively rare, found only on 1971-73 Buicks and 1973 Pontiacs.
How do I choose the right size carburetor?
To arrive at the most appropriate carburetor choice, there's a basic formula: engine displacement multiplied by maximum rpm divided by 3,456. For example: a typical 355ci small-block—a 0.030-over rebuild—with a 6,000-rpm max engine speed would work well with a 616-cfm carb ((355 x 6,000) 3,456 = 616.32).
What does adding a bigger carburetor do?
Up to a certain point, using a bigger carburetor does add more power…. assuming the engine was originally equipped with one too small to provide all the fuel/ air the engine can use. And while it sounds counter productive, it can actually mean using LESS fuel, if you drive with fuel economy in mind.
What's a good size carburetor for a Chevy 350?
Any 600 cfm carb will do just fine.
Is a 2 or 4 barrel carburetor better?
One of the main advantages of a 2-barrel carburetor is its simplicity. It has fewer parts and is easier to maintain and repair than a 4-barrel carburetor. This makes it an ideal choice for daily commuting, light-duty hauling, and city driving.
What cfm is a stock quadrajet carb?
Two basic sizes of Quadrajet were produced over the years; 750 and 800 CFM versions. The 800 CFM unit (identified by a slightly larger primary venturi) was relatively rare, found only on 1971-73 Buicks and 1973 Pontiacs.
How much horsepower will a 650 cfm carb support?
Typically for the size selection you need to know approx. horsepower (be honest). 600 cfm carbs best suited for low 300hp, 650cfm 340hp-390hp, 750cfm 400hp-460hp, 950cfm 490hp-575hp 1000cfm 575-595, 1050cfm-1250 600hp and up.
Can a carburetor be too big for an engine?
As in life, so it is with carbs: Compromises are called fora fine balance. Not too big because youll lose driveability. Not too small or the carb becomes a major bottleneck. For most hot, dual-purpose cars, pulling about 1.0-inch-Hg manifold vacuum at WOT, max rpm on the dyno isnt far off.
How do I know what size carburetor I need?
Take 350 ci multiplied by 5,500 maximum expected rpm equal 1,920,000. Then, take 1,920,000 and divide this number by 3,456 rpm and get 557 cfm, which calls for a 600-cfm carburetor if you're planning 5,500-6,000 rpm. If you're expecting a maximum of 6,500 rpm, you're going to need a 650- to 700-cfm carburetor.
Is a 600 cfm carb big enough for a 350?
Take 350 ci multiplied by 5,500 maximum expected rpm equal 1,920,000. Then, take 1,920,000 and divide this number by 3,456 rpm and get 557 cfm, which calls for a 600-cfm carburetor if you're planning 5,500-6,000 rpm. If you're expecting a maximum of 6,500 rpm, you're going to need a 650- to 700-cfm carburetor.
