Mercury Racing's new 520

Mercury Racing has announced the latest addition to its high performance sterndrive family -- the 520. The naturally aspirated engine provides recreational boaters a cost-effective power option that the company says fits nicely, in both value and performance, between MerCruiser's 8.2-litre MAG HO and Mercury Racing's 525 EFI.

The low-cost sterndrive features digital throttle and shift and is backed by a two-year limited factory warranty.

The 520 shares the same CNC machined cylinder block used on its MAG HO cousin and Mercury Racing's 502 cubic-inch-based sterndrive family. Mercury Racing enhanced the 520's power and torque by increasing the cylinder bore size for an additional 21 cubic inches of displacement (344 cc) to 523-C.I.D. (8.6 litres). The larger displacement, combined with Mercury Racing cylinder heads, multiport fuel injection and an electronic throttle body results in nearly 100 additional horsepower over the 430hp MAG HO.

Mercury says the 520 'isn't your father's MerCruiser'. The engine was developed to provide recreational boaters a low-cost option for gaining access to Mercury Racing's group of high-performance sterndrive propulsion systems. The engine package is destined to be a game changer for a variety of recreational boating segments including runabouts, sport boats and cruisers.

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 optimises fuel and spark timing independently for each cylinder for enhanced engine running quality, performance, fuel economy, and durability.

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, minimising 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 synchronisation. Furthermore, it enables shadow mode for multiple engine applications, where two throttle levers can operate up to four engines.

The engines are available in a range of colours, including the standard Mercury Racing Blue Metallic pictured, 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 available for enhanced performance in virtually any application.