Looking to boost your Mercury Racing outboard engine's cooling efficiency and increase airflow to unlock more horsepower?
 
Our high-performance Light-Weight Race Cowl Louvers, engineered as a direct replacement for Mercury OEM part number 788582 (and might be compatable to fit on the top of cowls with legacy part numbers 77376-2, 78858-2, 78857-1) are designed specifically for Mercury Racing 2.5 Liter S3000, 300 Drag, F1, motors as well as F1H20, APBA F200, USF1, and other high-performance racing to optimize engine ventilation.
 
By reducing under-cowl temperatures by up to 15 degrees Fahrenheit, these louvers allow your powerhead to breathe easier and with cooler air, improving combustion efficiency, throttle response, and overall engine output.
 
Crafted from premium Aluminum 6062 (AL-6062) — a high-strength, magnesium-silicide-based alloy — these marine-grade louvers offer superior durability, heat resistance, and weight savings compared to standard plastic or composite vents.
 
AL-6062 provides an ideal strength-to-weight ratio (tensile strength up to 330 MPa) and excellent thermal conductivity (~167 W/m·K), enabling the louvers to efficiently dissipate excess engine heat and maintain stable internal temperatures during high-RPM operation.
 
This reduction in heat soak helps preserve engine components, prevents power loss due to heat-induced detuning, and supports maximum horsepower output in competitive marine racing environments.
 
These performance outboard cowl vents are precision-stamped using CNC-machined dies, ensuring a clean edge finish with optimized slat angles and vent spacing to maximize airflow without disrupting aerodynamics.
 
Each louver is heat-treated to a T6 temper, increasing hardness and fatigue resistance to withstand high-speed vibration, salt spray, and long-term thermal cycling.
 
Whether you're running offshore at wide-open throttle or navigating tight corners on the course, these Mercury Racing cowl louvers deliver consistent cooling, reduced engine wear, and improved reliability under extreme conditions.
 
Finished with a fine glass-bead texture and available in anodized red, blue, or black, our AL-6062 race louvers combine aggressive styling with excellent corrosion resistance — built to perform under pressure and look sharp while doing it.
 
Whether you're a competitive racer or a performance boating enthusiast, this is a bolt-on performance upgrade that delivers measurable improvements in airflow, cooling efficiency, and long-term engine health.
 
Include two (2) Aluminum Light-Weight Race Cowl Louvers, each measuring 3" x 13.75". Compare to Mercury OEM Shield 788582 priced at MSRP of $116.95 each!
 
Contact Mike Hill at +1-714-697-1716 or email mike@buckshotracing77.com for technical support.