SPAL BEAST 3700 19-Inch 850W Brushless Cooling Fan Kit

The SPAL BEAST 3700 is a high-output flush-mount electric cooling fan designed for custom radiators, performance vehicles, engine swaps, racing applications and other demanding cooling systems. Its sealed 850-watt brushless motor delivers up to 3,700 CFM of airflow while the compact fan assembly helps conserve space behind the radiator.

Integrated power and signal electronics provide soft-start operation to reduce electrical inrush spikes. The fan also supports digital speed control and incorporates protection strategies for excessive temperature, over-voltage, under-voltage and locked-rotor conditions. A compatible jumper harness is included with this package.

Features

• High-output SPAL BEAST 3700 cooling fan
• Up to 3,700 CFM airflow rating
• 850-watt sealed brushless motor
• Flush-mount configuration
• Compact design with approximately 3.2-inch fan depth
• Integrated power and signal electronics
• Soft-start operation helps prevent electrical inrush spikes
• Supports digital and variable-speed control
• Motor protection for temperature, voltage and locked-rotor conditions
• IP6K9K-rated motor protection against dust, water and high-pressure spray
• Jumper harness included

Specifications

• Brand: SPAL
• Series: BEAST 3700
• Nominal Fan Size: 19 inches
• Airflow: Up to 3,700 CFM
• Motor Power: 850 watts
• Motor Type: Sealed brushless
• Mounting Style: Flush mount
• Approximate Fan Depth: 3.2 inches
• Fitment Type: Universal custom installation
• Manufacturer Part Number: 30107521-PKG

Fitment

This is a universal performance cooling fan and is not a direct replacement for a specific vehicle. It is intended for custom radiator, shroud, engine-swap, off-road, racing and high-performance cooling applications with sufficient mounting and electrical capacity.

Fitment note: Before ordering, measure the radiator core, shroud opening and available clearance between the radiator and engine accessories. Confirm the complete fan dimensions, mounting-point locations, airflow direction and required clearance before fabricating a shroud or mounting brackets.

Electrical Requirements

This is an 850-watt high-output fan that places a substantial demand on the vehicle’s electrical system. Verify that the alternator, battery, power cable, ground path, connectors and circuit protection can support the fan’s requirements under continuous operation.

The included jumper harness does not necessarily provide the complete power circuit or temperature-control system. A compatible SPAL controller, temperature sensor, adapter harness, fuse, power wiring or other electrical components may be required depending on the intended control strategy.

Do not connect the fan using wiring, relays, switches or circuit protection intended for a conventional low-current fan. Follow SPAL’s current wiring instructions for part number 30107521-PKG.

Recommended Use

• High-performance street vehicles
• Racing and autocross vehicles
• Engine-swap projects
• Custom aluminum radiators and fan shrouds
• Off-road and severe-duty cooling systems
• Applications requiring high airflow at low vehicle speed

What’s Included

• One SPAL BEAST 3700 brushless cooling fan
• One compatible jumper harness

Temperature sensor, fan controller, main power wiring, fuse, circuit-protection components, custom shroud and mounting hardware are not included unless otherwise specified.

Installation

Professional mechanical and electrical installation is strongly recommended. Secure the fan to a properly supported shroud or mounting structure rather than allowing its weight to rest directly on the radiator core. Route all wiring away from exhaust components, sharp edges, belts, pulleys and other moving parts.

Before operating the vehicle, verify correct polarity, airflow direction, fan-speed control, circuit protection and charging-system voltage. Test the complete cooling system under normal operating temperature and load conditions.