How Much Do Headway Performance Heads Flow?
The infamous question “How much do they flow?”, has become a warning sign. Contrary to trade publications and advertising claims, a head that flows more will not necessarily make more power. Those who chase only big air flow numbers usually go home early wondering why they have an under performing engine. While a flow bench is a useful tool in the development of racing cylinder heads, proceed with caution! A particular head that has more air flow isn’t always the best selection. Large air flow itself it does not work. When evaluating a set of heads, air flow should not be the first concern. More important is the cross sectional area (which influences how much a port will flow – larger areas typically flow more air) as well as having an appropriate port shape for the application. If any of these are addressed incorrectly, the best flowing head on the bench will never make a competitive amount of power. If you are interested in making real power or being the best in the class, don’t buy
