Exceptional Low and Mid-Lift Flow
This is what we like to refer to as “area under the curve” when it’s related to cylinder head airflow figures. Once again AFR port and combustion chamber designs excel in this area (as well as peak flow) and this is a key often overlooked in design element for performance cylinder heads. Everyone is always discussing peak flow but here is a wakeup call for you. Look at the low lift numbers more closely when comparing heads. Also, contrary to popular belief, a head with strong low and mid lift flow doesn’t mean it will have stronger power in the lower and middle part of the horsepower curve (although it will make more there), it means it will make more power everywhere due to the fact that every time an intake and exhaust valve opens and closes it will be able to move more air in total than a head with similar peak numbers and a much softer area under the curve. In fact if anything, an efficient head with better low and mid-lift flow numbers usually shows its stuff up top allowing the torque curve to hang on a little longer producing a higher peak HP figure and carry much better past peak as well (not roll over as quickly). That’s because at the higher RPM’s, when there is much less time to fill and evacuate the cylinder, airflow demand of the engine is at a premium and any little extra you cram in there (and remove) will pay you big dividends.