American outboard circuit racing took a step towards the future with the recent approval and homologation by the American Power Boat Association of Mercury Racing Apex Series four-stroke outboards for Outboard Performance Class (OPC) competition. For the 2022 racing season, the Mercury Racing 200 APX motor has been approved for the OPC Formula 200 tunnel boat class, and the Mercury Racing 360 APX is approved for the OPC Mod U class. The announcement was made by Sherron Winer, OPC Category Chair, following the Jan. 28 APBA annual meeting.
“Mercury Racing is excited to bring a new level of technology and sustainability to OPC racing,” said Stuart Halley, Mercury Racing general manager. “These outboards will offer fans a thrilling show and racers outstanding performance with a significant reduction in tuning and maintenance expense, all with a reduction in exhaust emissions that benefits everyone.”
The APBA is the United States sanctioning authority for the Union Internationale Motonautique (UIM), the world governing body for powerboat racing. The Mercury Racing 200 APX and 360 APX outboards are also approved for competition outside the United States in the UIM F2 and F1 classes respectively.
The Mercury Racing 200 APX outboard was designed to replace the Mercury Racing 200XS OptiMax and older two-stroke V6 outboards currently raced in the OPC Formula 200 class and is the first V6 four-stroke competition outboard produced by Mercury Racing. The two-stroke outboard models are no longer in production.
“The two-stroke outboards will remain eligible for Formula 200,” said Winer. “Racers are often resistant to change, and we anticipate there will be a gradual transition to the new four-stroke outboards. The truth is that the two-stroke outboards have almost become vintage equipment, and it’s time to make a move towards a sustainable future. We are delighted that Mercury Racing is offering our racers this new outboard technology.”
A Mercury Marine 3.4-liter double overhead cam/four-valve powerhead with a 64 degree cylinder angle is the foundation of the Mercury Racing 200 APX outboard. The 360 APX outboard is based on a modified version of the Mercury Racing 300R 4.6-liter V8 powerhead. To prepare these engines for competition, Mercury Racing raises the compression ratio from 10:1 to 11:1, increases peak RPM, and fits a lightweight carbon fiber cowl that incorporates forced cold air induction. A robust 12-inch midsection features a structural wet sump driveshaft housing and integrated power trim and lift with remote pumps. To increase propeller speed to match that of two-stroke racing outboards an overdrive spur gearset increases the input shaft speed to the gearcase, and produces the desired left-hand propeller rotation. The engines do not require expensive high-octane racing fuel; both make full power on 91-octane (98 RON w/ E10 max) pump gasoline.
“Ultimately the performance of the 200 APX outboard will be proven on the course,” said APBA President Chris Fairchild, a multi-time tunnel boat champion who served as a consultant and test driver to Mercury Racing during development of the Apex Series outboards. “Our current Formula 200 champ, R.J. West, has conducted back-to-back testing of his current two-stroke rig and the 200 APX and I think he came away impressed. The racers will need some seat time to adjust to the torque curve of the four-stroke engine, but these new outboards offer so many advantages I think most teams will be ready to make the change. The 200 APX weighs only 30 pounds more than the two-stroke motors, and offers a huge advantage in reduced maintenance and tuning costs. Most teams are frequently replacing two-stroke pistons and reed valves and it’s become hard to find parts for the older carbureted motors. We put more than 60 hours of high-speed testing on the Apex motor and its last lap was faster than the first. Most teams are going to race a 200 APX for an entire season and will only need to change the oil.”
Mercury Racing 200 APX and 360 APX outboards are available for order now by qualified racing teams.