Mercury Racing Introduces New 520 Sterndrive

Mercury Racing, Fond du Lac, Wisconsin has introduced its latest addition to its high-performance sterndrive family; the 520. According to the company, the naturally aspirated engine will provide recreational boaters a cost-effective power option that falls between MerCruiser's 8.2L MAG HO and Mercury Racing's 525 EFI.

Mercury says the engine is designed for several vessel types including runabouts, sport boats and cruisers.

The 520 sterndrive features digital throttle and shift and is backed by a two-year limited factory warranty. It shares the same CNC machined cylinder block used on its MAG HO cousin and Mercury Racing's 502 cubic-inch-based sterndrive family.

Engine Details
Mercury Racing enhanced the 520's power and torque by increasing the cylinder bore size for an additional 21 cubic inches of displacement to 523-C.I.D. (8.6 L). The larger displacement combined with Mercury Racing's cylinder heads, multi-port fuel injection and an electronic throttle body results in nearly 100 additional horsepower over the 430hp MAG HO. All of this power comes from 87-posted octane (R+M)/2, (91 RON) global pump gas.

The CNC machined cylinder block contains Mercury Racing's designed components including a balanced crankshaft, forged I-beam and shot-peened connecting rods and forged aluminum pistons. The company's aluminum cylinder heads feature optimized valve angles for improved airflow. A carburized hardened camshaft is used for enhanced durability. Performance cam profiles, combined with larger valves, pack more air through the engine to produce increased power and torque. The 520's greater displacement, combined with enhanced airflow, results in mid-range power delivery and consistent pull through the engine's rpm operating range.

The 520 is closed cooled for more uniform temperature distribution, optimal running quality and longer life. It comes equipped with a 65 amp charging system, providing power for an array of marine electronics.

The 520 features the same Propulsion Control Module (PCM 09) microprocessor as found on the 565 and QC4v family. In addition to digital throttle and shift control, the PCM optimizes fuel and spark timing independently for each cylinder for enhanced engine running quality, performance, fuel economy, and durability.

Engine Guardian System
The PCM computer also drives Mercury Racing's exclusive Engine Guardian System. Engine Guardian monitors engine functions and indicates when parameters go out of specified range, minimizing the risk of engine damage. This “smart” technology not only detects and alerts the boater of a problem, but it also processes the data and reduces power to a maximum, safe level that allows the boater to continue operation. Engine Guardian also has the ability to proactively help prevent engine overheating by sensing not only engine temperature, but exhaust coolant temperature as well. By sensing engine coolant and exhaust coolant temperatures, the system can take action in advance by reducing engine power before temperature related engine damage occurs.

The PCM enabled system also features one-touch Smart Start and automatic throttle synchronization. Furthermore, it enables shadow mode for multiple engine applications, where two throttle levers can operate up to four engines.

A total of 11 colour options, including the standard Mercury Racing Blue Metallic, are available to fit virtually any style or theme.

The 520 is available with Bravo One XR, Bravo One XR Sport Master (standard and short) and Bravo Three XR drive options. The Mercury Racing Integrated Transom System (ITS) is also available. A wide variety of Mercury Racing propellers are also available for enhanced performance.

Mercury Racing says the engine complies with both EPA and CARB exhaust gas emissions limits.

Mercury Racing, a division of Mercury Marine, is a leading provider of high-performance marine propulsion systems for boaters worldwide.