# Readers ask: What Size Carburetor Do I Need For A 454?

## What cfm carb do I need?

How to calculate Carburetor CFM. The formula for calculating how much CFM (cubic feet per minute) your engine requires is: CFM = Cubic Inches x RPM x Volumetric Efficiency ÷ 3456. Any ordinary stock engine will have a volumetric efficiency of about 80%.

## How do I know what size carburetor to buy?

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).

## How much horsepower will a 750 cfm carb support?

A 750DP on a 330hp-400hp 5.7 with a dual plane intake (performer rpm) is easy to tune and will make max power to boot.

## Is 600 cfm carb big enough?

A 600-cfm carburetor may perform quite well on a stock 350 Chevy. However, the minute you start weaving in power adders like a hotter cam, a dual-plane performance intake manifold, and aluminum heads you’re going to need 700-750 cfm.

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## How much horsepower will a 650 cfm carb support?

So, using your Google-Fu you type “How much power can a 650 cfm carb support?” Well, chances are that you’ll get answers in the 450-470 hp range, but that’s not really the right way to look at it.

## What happens if your carburetor is too big?

If the barrels are too big, the loss of air velocity means the cylinder will not fill to its full capacity. An engine with a carb that is too big will put out less Torque and Horsepower. It will be difficult to drive due to poor low-end torque. If you drag race your car, an oversized carb will produce slow 60 ft.

## What can I spray in my carburetor to start my engine?

Remove the air filter and shoot a one-second burst of an aerosol petroleum-based lubricant (not starting fluid, silicone or Teflon spray) directly into the carburetor throat. Try starting. If the engine starts and then dies, that confirms you’ve got a fuel problem.

## Can a carburetor be to big?

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 you adjust a carburetor?

Here’s How To Adjust a Carburetor

1. Remove the Engine Air Filter. The air cleaner and filter assembly must be removed for you to access the carburetor.
3. (Optional): Hook up Vacuum Gauge.
4. (Optional): Set Baseline.
5. Warm the Engine Up.
6. (Optional): Adjust Idle Speed Screw.
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## How much horsepower does a carburetor add?

After you fix what’s limiting performance, an Edelbrock Performer intake can add as much as 10 HP. The FAQ forum is a good place to ask questions. There are differences between engines and performance improvements.

## Are carb spacers worth it?

Spacers are said to improve air/fuel vaporization through and out of the carburetor. Anytime the air/fuel charge has to turn sharply coming off the carb, it increases the chance of separating the fuel from the air.

## How do you increase CFM on a carburetor?

In just a few minutes working with a file, you can augment this mod by applying a radius to the top edges of the choke horn. This increases the flow about 3 to 5 more cfm. You may see carbs that have been reworked for a higher performance by milling off the choke horn.

## What size carb do I need for a 350?

A stock 350 Chevy may have a 600-cfm Carburetor. The minute you start weaving in power adders like a hotter cam, a dual-plane performance intake manifold, and aluminum heads, you’re going to need 700-750 cfm.

## What is a 600 CFM carburetor?

A 600 CFM carburetor can be a great choice for a wide variety of engines. They can be a perfect match for a highly tuned race engine around 300 cubic inches all the way up to a street tuned big block.

## What size carb do I need for a 383 stroker?

Carburetor For 383 Stroker recommends a 650 cfm carburetor. A 750 cfm carburetor will make the engine more powerful, but it is the largest that should be used unless the engine is being used for racing.