While the buzz and chatter about the XCAT Racing version of the Mercury Racing Verado 400R have been more or less constant since the popular four-stroke outboard was introduced at the 2015 Miami International Boat Show in February, the public got its first look at the new engine moments ago in the Florida Powerboat Club’s Key West Poker Run Village. Dubbed the Mercury Racing ROS—shorthand for Race Offshore—the supercharged outboard will see its official racing debut Nov. 19 during the 2015 XCAT World Series in Dubai, United Arab Emirates. According to a press release from the Fond du Lac, Wis., marine engine company, the XCAT series partnered with Mercury Racing in the development of the 2.6L engine that will “replace the existing fleet of Mercury Racing 2-stroke 2.5L EFI race outboards.”
Mercury Racing announced its new ROS outboard engine during the Key West Poker Run on Thursday.
“We are very excited to launch our new Race Offshore competition outboard,” said Erik Christiansen, Mercury Racing’s general manager, in the release. “The venerable 2.5 EFI 2-stroke Mercury’s have been a mainstay for many years and is still a solid product. The ROS builds on that foundation while using the four stroke technology today’s market demands.”
“We worked with the World Professional Powerboating Association (the promoter of the XCAT series) to develop a strong, reliable engine that meets the new U.A.E. exhaust emissions requirements,” he continued. “The ROS will be homologated into the Union Internationale Motonautique technical specifications for XCAT. Next season will be a transitional year with the entire XCAT field switching to the ROS four-strokes for 2017. I’m looking forward to seeing our new engine compete in Dubai.”
Producing 400 hp from 6,400 to 7,000 rpm according to its technical specifications material, the ROS outboard’s 400R powerhead is mounted on an all-new race midsection featuring Mercury Racing’s heavy-duty swivel clamp bracket assembly. A SportMaster gearcase transfers the engine’s power to the water.
Similarities between the two engines reportedly begin and end at the powerhead. The new midsection for the ROS boasts a billet aluminum housing. Mercury Racing reportedly developed the new midsection to lower the overall engine center of gravity. The 10-inch midsection, coupled with the heavy-duty swivel clamp bracket assembly, brings the overall engine mounting height to 15-inches, which matches the current 2.5L EFI outboard’s setup. A carbon-fiber lower cowl “conceals the transition” of powerhead to midsection.
According to the release, “The low CG—combined with solid upper and lower engine mounts—is critical for overall handling at competition speeds, particularly when powering the high-performance catamarans into and out of corners.”
The ROS also features a remote dry sump system that holds 8 liters of Mercury Racing Four Stroke Oil, which is the same semi-synthetic 25W-50 oil used in the company’s high-output QC4v stern drive engines. The lower front cowl features dual rigging tubes, one each for fuel and electrical systems. Thanks to the integration of SmartCraft technology into the Verado platform, the ROS outboard brings XCAT “into the digital” age with Mercury Digital Throttle & Shift (DTS), which eliminates the need for throttle and shifter cables.
Mercury Racing also developed an all-new line of five- and six-blade CNC cleaver propellers specifically for the ROS. Rated for 400 hp, the lab-finished props were developed specifically for surface-piercing applications and are available with 13-, 15-, 18- or 21-degree rake angles. The props are offered in a variety of pitch sizes.
Of course, for present and future high-performance sport catamaran owners, the big question is when the ROS outboard will be available to consumers. A spokesman for Mercury Racing said the company “had no specific plans” for such a release at this time.
As for the XCAT series organizers, they reportedly are eager to embrance the new ROS outboard package.
“All those involved in the XCAT World Series are looking forward to the introduction of the new Mercury four-stroke engines,” said Ronan Morgan, the WPPA’s chief executive officer, in the press release. “Not only are these environmentally friendly, they are reliable and provide a huge increase to the horsepower and torque, which are essential for an action-packed weekend of racing.
“As promoters of XCAT Racing, the WPPA have had a long-standing relationship with Mercury Racing,” he added. “We’ve worked closely together in the testing and development of the engine to provide the ultimate in performance and fan experience.”
Mercury Racing ROS Outboard Specifications at a Glance
Propshaft Rated Horsepower: 400
Maximum Operating Speed: 6,400-7,000 rpm
Cylinders/Engine Configuration: In-Line 6, 24-Valve Direct-Acting Double Overhead Cam (DOHC)
Displacement: Cubic Inches, 158.5—Liters, 2.6—Cubic Centimeters, 2,598
Bore & Stroke: Inches , 3.23 x 3.23/Millimeters, 82 x 82
Induction System: Supercharged with Charge Air Cooling and Electronic Boost Control Fuel System: Computer Controlled Sequential Multi-Port Electronic Fuel Injection
Fuel Octane Requirements: Unleaded 91 R + M/2 (98 RON)