Cylinder head porting is a fairly simple premise – increase airflow into the combustion chamber to make more power. However, making it actually happen requires a bit of work. Improvements to airflow quality and quantity come from porting in the bowl area between the valve seat and valve guide because it is an area of restriction.

Cylinder head porting refers to the process of modifying the intake and exhaust ports of an internal combustion engine to improve their air flow. Cylinder heads, as manufactured, are usually suboptimal for racing applications due to being designed for maximum durability.

Hand porting a set of cylinder heads takes skill and expertise to achieve consistency. Even then, it’s hard to match the results that can be achieved much more quickly and easily with CNC porting.

It's a big subject to cover, so to chop it down to more manageable bites, we are going to apply five basic rules: 1.Locate the point of greatest restriction, and work on that first. 2....