Seven Marine 557

Seven Marine unveils 557-horsepower outboard.

March 30, 2011

Funny how things come full circle. Back in the 1980s, the now-defunct Outboard Marine Corp. (OMC) built a V-8 two-stroke outboard under the Johnson and Evinrude brands. It was such a remarkable beast that the engines — discontinued only a few years later — are collectible today. But most reside in the Middle East, wasting on hulks or, if running, used on patrol boats in military applications.

Then, just a few years ago, Yamaha bravely developed a new V-8 four-stroke, and boatbuilders rushed to design boats around it. Who’d have thought?

Well, Eric Davis, for one. He and his brother Brian had an itch for one-upmanship that’s not surprising considering their racing background — and their gene pool. Their dad is Rick Davis, a former Mercury engineer who built his early career in the most compelling business rivalry that ever existed — Mercury against Evinrude — and helped develop Mercury’s OptiMax direct-injection technology. Davis went on to oversee the development of the Verado program and then the Zeus pod-drive, three of Mercury’s most innovative and successful products.


So, with that upbringing and a burn to “show ’em,” Eric combined proven components from ZF Marine, GM, Latham Marine and other industry-leading suppliers to design the world’s most powerful outboard motor and, when the first production units are delivered later this year, the first with joystick steering.

Even while the Seven Marine motors that were unveiled at the Miami International Boat Show in February remained dry on an Intrepid 370 transom, naysayers piped up.

“Too heavy!” they exclaimed. But the supercharged 557 weighs in at 1.8 pounds per horsepower. Compare that with Yamaha’s naturally aspirated 350 hp V-8. It weighs in at 2.4 pounds per horsepower.


“Too expensive!” said others hearing the rumored sale price of $69,000. But that calculates out to just $123.88 per horsepower. Well, they might have a point there, since the Yamaha F350 sells for $85 per horsepower, but that’s without a transmission, an octane scaler, an overboard exhaust selector switch and, at present, capability for joystick steering for easy docking. Those all come with the 557.

So what else comes with the 557 for that extra $39 per horsepower? Most importantly, the ability to reduce weight and drag by accomplishing with two motors what it takes three and four competitive motors to do. And, by reducing motors on board, maintenance costs are reduced.

Consider too that hydraulic power steering is integrated into the 557 — not bolted on as in every other outboard application — and you can see a more elegant rigging arrangement that also reduces installation costs and, it is hoped, ongoing maintenance. Add to that closed-loop cooling that isolates the engine from salt water, mud, sludge and other enemies of traditional raw-water cooling systems, and another benefit tips the scale in favor of economy.


Need some icing for the cake? Seven Marine will paint your 557s whatever color scheme you want!

So, a typical triple 350 setup could run $110,000, while twin 557s would give you more horsepower, less weight and less maintenance at about $140,000 to $150,000.

Of course, all that’s theoretical — since nobody has driven a Seven Marine 557 — and until the promised sea trials take place later this summer, it will remain theoretical. What is not theoretical, however, is that this team has brought together innovative thinking in this motor in a way that’s going to appeal to the same boater who would choose a Ducati over a Harley or an Intrepid over a production boat. If the 557 lives up to its builders’ expectations, it will quickly elbow its way into the marine marketplace as a high-performance, competitive alternative to production power.


I like that thinking.

Seven Firsts
-First to exceed 350 horsepower

-First outboard to use a horizontal crankshaft orientation

-First to use a stock V-8 auto engine as a power head

-First outboard to use closed-loop cooling

-First outboard to use clutch shifting

-First to integrate hydraulic steering in the motor mounts

-First outboard to offer custom colors


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