The CFM (Cubic Feet per Minute) Calculator helps you determine the minimum carburetor size for your engine. The carburetor's job is to mix the right amount of fuel with air before it enters the engine. If the carburetor is too small, the engine won't get enough air, leading to poor performance. If it's too large, the engine may get too much air, making it hard to tune.

To use the CFM Calculator, input the engine size (in cubic inches) and the maximum RPM (Revolutions Per Minute). The calculator will provide the recommended carburetor size based on these parameters. Ensuring the correct CFM is crucial for optimal air-fuel mixture, which impacts the engine's combustion efficiency, power output, and overall performance.

To calculate CFM, you take the value of the engine size multiplied by the max rpm and the volumetric efficency, and divide the value by 3456. The number 3456 is derived from the constants used to convert the units. 1728 is the number of cubic inches in a cubic foot. The factor of 2 accounts for the fact that a four-stroke engine completes one intake cycle every two revolutions.