“”An internal combustion engine functions fundamentally as an air pump, with its power output hinging on the efficiency of air intake and exhaust. The two most effective methods to increase airflow are through enhancing the engine’s displacement or its revolutions per minute (RPMs). Increased displacement amplifies the volume of air per cycle, while a higher RPM count escalates the frequency of cycles within a given timeframe. Often, augmenting engine displacement or redline is prohibitive due to the exorbitant costs or impracticality associated with constructing a bespoke motor with an enlarged bore, increased stroke, or the lightening of internal components to boost RPM.

To further amplify power, one can look to improve volumetric efficiency. Typical enhancements include adopting less restrictive intakes, headers, and exhaust systems to augment airflow into and out of the engine. Nonetheless, optimization efforts frequently encounter a critical bottleneck: the cylinder head. The ports within the head represent the final arbiter of airflow to and from the combustion chamber, embodying a crucial segment of the engine’s airflow tract.

S2000 Head History

More than two decades after its release, the Honda S2000 remains one of the most efficient normally aspirated engines in terms of head flow. At its inception, it surpassed all competitors in the Sport Compact category, outperforming even those with larger valves. The S2000 was conceived as a cornerstone of Honda’s 50th-anniversary celebrations, with an initial power target of 220 horsepower to achieve a specific power-to-weight ratio. However, the vehicle exceeded its expected weight, necessitating an increase in power to 240 horsepower to meet the desired ratio.

Honda achieved this increase primarily by expanding the head ports and enhancing airflow through the cylinder head. This modification, while effective in boosting power, resulted in an engine that exhibited sluggish performance at lower revs, only showing its full potential beyond 5000 RPM. The original 2.0-liter engine required higher RPMs to achieve the air velocity necessary for responsive performance. The subsequent expansion to a 2.2-liter displacement addressed this by moving a greater volume of air with each stroke, which improved port velocity and responsiveness beginning at 3500 RPM.

Air Velocity Focus

There exists untapped potential in the cylinder head that can be harnessed to increase power without compromising engine response. The focus should not merely be on enlarging the ports but rather on refining their shape to address specific areas that constrain optimal airflow. Many head porters opt to increase the port size because it is straightforward and yields impressive figures on flow charts and visual inspection. However, such modifications can diminish air velocity across the midrange RPM spectrum, necessitating higher RPMs to achieve the desired responsiveness, as observed with the F20C engine. While this approach may show increased peak power on a dynamometer, it can result in longer acceleration times and potentially reduced trap speeds on the track’s straights.

New Direction

As enthusiasts, we understand the fatigue that comes with navigating through complex product stages and the frustration of being told that additional parts are necessary for optimal performance. We believe in simplicity and transparency. Therefore, we offer two straightforward options tailored to your needs: one is designed for OEM bottom ends, and the other is suited for built strokers or motors that are engineered to rev higher.

Our team has invested years in finding the right head porter to take over from our revered predecessor. We sought an expert whose philosophy centered on air velocity rather than just head flow, which led us to the high-performance motorcycle sector. Engines in this domain demand high revolutions and a wide operating range, accentuating the importance of air velocity optimization for performance.

This search led us to someone who stands out as the leading motorcycle head porter in the industry. During our discussion, he shared his unconventional yet effective approach: “I haven’t flowed my heads in years.” He focuses on meticulously scanning the port shape, pinpointing and improving areas that slow down the airflow, with subsequent validation through dynamometer testing and real-world track performance.

We are proud to unveil our NEW velocity head program, crafted by a top-tier motorcycle head porter. This program heralds a new frontier in performance enhancements, simplifying the path to power without the clutter of unnecessary upgrades.