This article will give you a detailed look at a CFM carburetor calculator. Are you wondering how does a carb work? What does CFM mean in the carburetor? And other questions related to this topic can be found here that will surely benefit you and teach you something new.

What does CFM mean in the carburetor?

A carburetor is a device that works on mixing air and fuel and converts it into an even and steady flow of gas. It is an essential part of an engine and converts the fuel-air mixture into the most efficient burning. It is also used to maintain the engine’s balance of fuel and air mixture. The term CFM has the meaning of Cubic Feet per Minute, which measures the volumetric of air flowing into the engine.

How does a carburetor work?

It does this by precisely metering out the fuel for each piston stroke. A carburetor is a fuel-delivery system for engines. A carburetor’s function is to regulate the fuel-air mixture drawn into the engine by providing a specific amount of air to each quantity of fuel. This process is called carburetion. The velocity of a liquid or gas is measured using a venturi instrument. The tube we are talking about has the effect of accelerating the air at the moment of passing through it. To preserve mechanical energy, you must meet the increase in air velocity with a decrease in pressure. Such a decrease in pressure is sufficient to draw fuel from the fuel intake into the airflow. We want to achieve with this method to suck fuel into the engine. However, there is another question: how can we set the combination of fuel and air? In that case, we have two valves, and one is below the venturi while the other is above the same. At the very top, there is a valve called a throttle, which regulates how much air can enter. If the choke is closed, it is a matter of significantly less air flowing, which leads to a reduction in combustion in the engine due to a lack of oxygen. However, if we are talking about another valve located at the bottom, it is gas. When the air inside the carburetor increases, increasing the amount of fuel in the engine and the air means that the gas valve is open. Acceleration of the vehicle will occur by having enough oxygen for fuel and working with this combustion, and we release more energy needed to drive the engine.

Working principle of carburetor
Working principle of carburetor

How does the carburetor CFM calculator work?

You’ve probably heard of the Bernoulli equation, which represents the relationship between fluid density, pressure, and velocity in motion. Our carburetor calculator works based on that same equation, which has the same principle. The Carburetor CFM Calculator is a simple device that helps calculate the size of carb by using a chart of standard sizes. We can opt for several reasons why a carburetor may need to be replaced, including wear and tear or water damage. To determine the size of the replacement carburetor, a technician needs to know the dimensions of the old carburetor. The CFM Calculator can help technicians identify the size and dimensions of the old carburetor and compare it to the chart to find a suitable replacement. The Carburetor CFM Calculator can also be used by consumers who want to replace their carburetor. This type of calculator is designed to help you determine the CFM of your carb. This is important because the higher the CFM, the more air that can be drawn into the engine and the more power you can produce. This is especially important if you run an over-bored machine or have too much compression. You can use this product to determine how much air your engine is getting and what needs to be done to increase it.

In the following paragraph, you can see which formula is in the CFM motor calculator:

Cs = \frac{CID \cdot max RPM\cdot Eff}{3456}

All three parameters of this formula will be explained in the following paragraph:

Engine Size (CID) – performances the size of the engine but expressed in inches. The format in which the majority liter or cc (mL) is expressed

Max. RPM – speaks of the maximum number of revolutions in one minute.

Engine efficiency (Eff) – when we talk about standard engines, they will have about 80% efficiency in most cases, but they range from 95% to 110% efficiency when we talk about racing engines.

The last parameter of this formula is the constant “3456,” which is converted from inches to feet (1 foot is 12 inches).

How to use the carburetor calculator?

This calculator can help you calculate the volume of gas in a cylinder, the volume of air in a cylinder, and the compression ratio.  You will need to select your engine type and then choose the throttle position. It also provides a table of commonly used fuel/air ratios.

In the example, we will best explain how our calculator works!

It is a 360 cubic inch engine with 5,800 max rpm, and its efficiency is 80%. This will look like this with the CFM calculator:

First step: 360 CID engine x 5,800 max rpm = 2,088,000 cubic inches

In the following procedure, we need to multiply the above result by 0.80 because it is an engine with 80% efficiency.

Second step: 2,088,000 x 0.80 = 1,670,400 cubic inches

And in the last step, we convert cubic inches to cubic feet per minute by doing the following:

\frac{1670400}{3456} = 483.33 CFM