CFM Calculator

The CFM (Cubic Feet per Minute) Calculator is a valuable tool for determining the appropriate carburetor size for your engine. The function of the carburetor is to ensure the right mixture of fuel and air before it enters the engine. An undersized carburetor will restrict airflow, leading to subpar engine performance, whereas an oversized carburetor can introduce excessive air, complicating the tuning process.

To utilize the CFM Calculator, you need to enter your engine's size in cubic inches and its maximum RPM (Revolutions Per Minute). Based on these inputs, the calculator recommends the optimal carburetor size. Achieving the correct CFM is essential for maintaining an ideal air-fuel mixture, which directly influences the engine's combustion efficiency, power output, and overall performance.

The formula for calculating CFM involves multiplying the engine size by the maximum RPM and the volumetric efficiency, then dividing the result by 3456. This constant, 3456, is derived from conversion factors: 1728 represents the number of cubic inches in a cubic foot, and the factor of 2 accounts for the fact that a four-stroke engine completes one intake cycle every two revolutions.