Mercury Marine dropped a technological bombshell on the marine industry in February when it unveiled its 600-hp Verado outboard. The size of the 7.6L V-12 engine was the first of many impressions it made during the press reveal at Mercury’s Lake X test site near Orlando, Fla. Then its 1,260-pound heft further raised eyebrows. Features such as a two-speed automatic transmission, a gearcase that turns instead of the motor, and a 12-cylinder powerhead further showed that this outboard is one of a kind.
The V-12 Verado started life as a blank computer screen five years ago. It has no direct counterpart in the automotive world. When this project began, a great deal of time was spent just thinking about the power goals Mercury hoped it would achieve, according to Tim Reid, vice president of product development and engineering.
“The team took 18 months just talking to people like our boatbuilders to learn exactly what they needed, what we could do, and only then did we arrive at the general concept,” Reid says. “The V-12 idea came up pretty early because we wanted to make it normally aspirated, so we needed lots of displacement.”
A working prototype has been available for about two years and gave boatbuilders the ability to design boats with this engine in mind. The target audience for the outboard is owners of large, weighty boats, but there will be outliers, such as pontoon owners and those with medium-size center consoles. The $77,000 price tag might slow some buyers down, but the engine’s benefits are many.
The 7.6-liter engine block is die-cast at Mercury’s Fond du Lac, Wis., facility. It required some extraordinary equipment to construct. “It’s made using 4,500-ton die-cast machines, which are the biggest in North America,” Reid says, “and the die just barely fits inside; it’s the size of a truck.”
The V-12 block architecture is similar to that of Mercury’s V-8 Verado, with a 64- degree piston bank angle, but the bore and stroke are bigger (96mm by 87mm instead of 92mm by 86mm). Another difference is that the V-12 has a quad-camshaft design instead of Mercury’s V-8 and V-6 dual-cam configuration. The 600-hp Verado is a high-revving outboard with a wide-open-throttle ranging from 5,400 to 6,400 rpm.
Designing a mounting and steering system capable of handling a 1,260-pound outboard not only would have been a challenge, but also would have added even more weight to the transom. Instead, Mercury designed a gearcase that moves independently of the rest of the outboard. The design innovation creates two immediate payoffs. The first is that the engines can be mounted on 27-inch centers, which are only 1 inch more than the minimum separation needed for most twin-engine installations. That’s also less than the real estate required for a Yamaha F350 (28½ inches).
“We knew we wanted to have no more than a 27-inch center because we wanted to be able to put a lot of them on the transom to accommodate the ever-growing size of boats we were seeing,” Reid says.
Boatbuilders such as Formula, which offers its 500 Super Sport Crossover with five Mercury Racing 400Rs or 450Rs, can upgrade to four V-12 Verados and have more overall power while creating more space for people on the swim platform.
The other big payoff with a steerable gearcase is the increase in range of motion, from 30 degrees each way to 45 degrees when using the Joystick Piloting system at slow speeds. Without joystick use, the turning angle is restricted to 30 degrees each way for safety.
Mercury employed the German company ZF to supply the first two-speed transmission ever on an outboard. At idle, the tranmission starts in first gear, which has a 2.97-to-1 ratio. Then, as the boat gets on plane, it shifts imperceptibly to a final 2.5-to-1 ratio for higher top speeds and better fuel economy.
Another benefit of the two-speed transmission is that it uses a wet-sump clutch to make smooth shifts without the clunk that was once noticeable when using the joystick. Since the bulk of adding a second gear necessitated moving the gears above the lower unit, where they normally reside, the bullet size was able to be reduced for better hydrodynamics.
And for better grip without going to a single prop with a huge diameter, twin contra-rotating props are used with a four-blade in forward and a three-blade aft. Props up to 18.25 inches in diameter can be used to provide maximum bite. The Formula 500 SSC I tested reached a speed of 5 mph when backing down with responsive directional control. Although this engine isn’t designed for pure speed like the 450R, four of the V-12s pushed the near-24-ton Formula to a top speed of 60 knots.
Boats like the 50 SSC often come with power-hungry equipment, such as Seakeeper gyrostabilizers and open-cockpit air conditioners. For this reason, Mercury equipped the Verado with a 150-amp alternator, a significant bump up from the 400-hp
Verado’s 70-amp version.
The top of the cowling pops open, thanks to an electronic latch mechanism (modeled after a Porsche design, Mercury says). This feature lets the owner perform routine checks of the fluids, which can be drained and refilled via the dipstick tubes. The V-12 holds 14 quarts of oil, and there’s an electronic oil level monitor for those who don’t do manual dipsticks. Gear oil can be changed without hauling the boat, and there is no scheduled maintenance for 200 hours. The cowling doesn’t have to be unbolted and removed for five years or 1,000 hours.
The V-12 Verado is quiet, thanks to several sound-canceling features, including a chamber for the dual throttle bodies to breathe into. Usually, manufacturers rely primarily on the cowling to seal in noise, but according to Reid, “This engine would be quiet even if you took the cowling off.”
To further reduce noise and vibration, the V-12 Verado uses an “advanced midsection” that has four isolation mounts attached in the mounting ring at the belt line of the outboard, which isolates the powerhead.
During a test run of a Boston Whaler powered by three V-12 Verados, I asked the captain to shift into neutral, and I brought my decibel meter to the stern. It was a flat-calm day, so no wave splash or wind factored into the measurements. And the V-12s don’t have streams of cooling water splashing on the surface like other outboards.
The reading was 54 decibels. With the engines turned off, it was 48 decibels. In other words, 1,800 hp of Mercury power is only 6 decibels louder than nature.
This article was originally published in the April 2021 issue.