When it comes to cold air intake filters, size does matter. A larger filter can allow more air to flow to the engine, which can increase power and performance. However, a larger filter can also restrict airflow if it becomes clogged with dirt and debris. Companies like K&N offer many different types of air cleaner elements and air cleaner assemblies to fit a variety of carburettor sizes and shapes.
The shape and size dictate the ability of the air cleaner element to flow the maximum amount of air to the engine. K&N tests have shown that for most two- and four-barrel carburettors, the airflow is greater when the diameter of the air cleaner is large compared to the height. The only exception to the K&N rule is when a filter element is attached to a long channel, such as in the case of cold air intakes of EFI engines.For example, the 14-inch by 3-inch element in Chevy heavy-duty car air filters from the 1960s is the ideal size for many single-carburettor applications. But more importantly, those filters were used to straighten and diffuse air before it entered the carburettors.Do I really need an air filter? If you have an old 4 cyl with a carburetor that is difficult to fit an air cleaner due to area limitations, you can use the diameter of the air cleaner to help determine the area sufficient for the required airflow.In conclusion, size does matter when it comes to car air filters.
Companies like K&N offer many different types of air cleaner elements and assemblies that are designed to fit a variety of carburettor sizes and shapes.