Among the more immediate challenges facing domestic offshore powerboat racing is power for the Stock-class catamarans that compete on the Super Boat International circuit. Surplus supplies of the long-discontinued 2.5-liter, 280-hp two-stroke Mercury Racing outboard engines have dwindled to the point of scarcity—with prices that reflect it—in the high-performance pleasure cat and racing worlds. In short, there simply aren’t enough of the still-coveted two-stroke outboards to go around.
As reported on speedonthewater.com, two United States-based Stock-class racers are experimenting with alternatives for the 2.5L outboard. Gary Ballough believes the 200XS, a plug-and-play replacement for the 2.5, is the way to go. Scott Porta believes the 300XS model, which requires modification to run the 2.5L outboard’s incredibly durable, race-proven midsection is the right call. Both engines currently being tested on the SBI circuit are direct-injection two-strokes.
Running his 32-foot Doug Wright FJ Propeller catamaran, Ballough sees 200XS outboards as the power choice of the future for SBI’s Stock class. All photos courtesy/copyright Pete Boden/Shoot 2 Thrill Pix.
But Erik Christiansen, the general manager of Mercury Racing in Fond du Lac, Wis., believes a derivative of Mercury Racing’s Verado 400R—a four-stroke outboard that outweighs its two-stroke counterparts by approximately 200 pounds—is the best choice for the future of Stock-class competition.
“The 400R debuted it last year in XCAT racing,” Christiansen said. “That engine will be homologated into the Union Internationale Motonautique technical specifications for XCAT. “Next season will be a transitional year, but in 2017 all XCAT outboards will be four-strokes.”
Christiansen acknowledged that Stock-class racers are concerned about adopting a 400R derivative for a number of reasons, the primary ones being greater weight and higher cost. He also readily admitted that the Victory XCAT team that ran the 400-hp outboard engines near the end of the 2014 season placed ballast forward in their catamaran to maintain the proper center of gravity for the boat with its heavier four-stroke outboard.
Porta, who also runs a 32-foot Doug Wright called Papa’s Pilar, is in favor of the 300XS outboards becoming standard power for the class.
“The thing is, how many of the 280-hp engines blow up because people are blueprinting them to output 305 to 310 hp?” he said. “I think at the last race in Dubai, they lost six or seven of them. They’ve pushed those engines to the point where they’re not reliable. The four-stroke is going to be really reliable. It has a stock powerhead that is sealed. The cost of ownership will be lower. You won’t have to rebuild it for several seasons. You put gas in it, change the oil every now and then and go racing.
“The 300XS and Verado 400R—it’s hard to compare them in price because of their difference in power output,” he continued. “But dollar-to-dollar per (unit of) horsepower, they are similar. With the 300, you’re going to have to spend extra money to adapt it to the 2.5’s midsection. The 200 isn’t competitive, in my opinion, with the other engines. If you run the 200, the boats are going to slow down significantly.”
Christiansen said there are other trade-offs with adopting either the 200XS or the 300XS as possible replacement engines for the class.
“First, their both two-strokes, clean two-strokes but two-strokes, and the U.I.M. wanted a four-stroke,” he said. “If you’re looking at a stock 280-hp 2.5, the 300XS is probably the closest in performance to it, but it gives up a little bit on the bottom end to the 280-hp engine because the 280 has more rpm. Until you get to about 4,500 rpm, the 280 is stronger. And the four-stroke is stronger everywhere.
“The 200-hp engine isn’t in the same league as the others, but it’s easier as a replacement since it has a 2.5-liter powerhead and can be used with the midsection without modification,” he continued. “The 300-hp engine takes a bit more work—it requires an adapter plate to work with the 2.5-liter’s midsection.”
While Christiansen said he hopes Stock-class will consider the more-powerful, four-stroke outboard option as it would enable XCAT racers to compete in U.S. and domestic racers to compete in the XCAT series abroad under U.I.M. technical rules for the class, he emphasized that he believes that the members of class need to choose one engine and stick with it.
“It would be nice to see everybody racing together rather than racing separately,” Christiansen said. “However, whatever they think works best for them to go racing is great. I’d rather see them run the four-stroke, but if they decide the 200XS or the 300XS is the way to go, that’s fine. My hope is that they pick one instead of two—they don’t want to end up with two groups doing things separately in the same class. I hope they choose a common standard.”