# Often asked: How Big A Carburetor For 400+ Hp?

## 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.

## 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).

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

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.

## What happens when a carburetor is too big?

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. times.

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## How do I know what cfm carb I need?

The volumetric efficiency of the engines is a measurable value, and with an adequate carburetor will get the most efficiency out of the engine. The formula to calculate the amount of CFM (cube feet per minute) that a motor needs is CFM= Cubic Inches x RPM x Volumetric Performance ÷ 3456.

## 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 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.

## 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.

## Which carburetor should I use?

Any ordinary stock engine will have a volumetric efficiency of about 80%. Most rebuilt street engines with average bolt-ons have a volumetric efficiency of about 85%, while race engines can range from 95% up to 110%. Even with about a 10% cushion, a 500 CFM carburetor will handle this engine great.

## 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.
2. Locate Adjustment Screws.
3. (Optional): Hook up Vacuum Gauge.
4. (Optional): Set Baseline.
5. Warm the Engine Up.
6. (Optional): Adjust Idle Speed Screw.
7. Adjust the Air-Fuel Mixture.
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## How many CFM is a 1406 Edelbrock carburetor?

The Edelbrock 1406 Performer Series 600 CFM electric choke carburetor is a precisely tuned, quality-built carburetor that can handle the rigors of daily driving while delivering consistent, reliable street performance from day to day.

## Who makes Demon carbs?

Demon – Holley Performance Products.

## Can you have to big of a carburetor?

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. But there are no guarantees.

## How does a carburetor spacer work?

A carb spacer increases the distance between the intake manifold and the bottom of the carburetor, which reduces the velocity of the intake charge. A four-hole spacer helps to direct the air-fuel mixture, making the streams more efficient. It also assists in preventing reversion from the pressure pulses.