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Merc’s New Powerhouse

Supercharged 4.6-Liter V8 has best power-to-weight ratio in industry.

Eric Glaser was jet-lagged after traveling overnight from a Mediterranean holiday to Nashville, but you’d never know it. The Midnight Express co-owner stood smiling at the helm of his company’s 43 Open and looked back at the color-matched, 2,250 ponies hanging from its transom. “I didn’t want to miss this,” Glaser told me and then suggested to those aboard to get a handhold. With that, Glaser firewalled the throttles and a 52-knot cruise quickly escalated into a 79-knot WOT on the tabletop-flat lake. The five powerplants pinned me to my bolster seat, the mid-range torque on full display. It was a fitting reception from Mercury Racing’s new, 450-hp powerhouse.

Midnight Express 43 Open with quint Mercury 450Rs

Midnight Express 43 Open with quint Mercury 450Rs

The Fond du Lac, Wisconsin manufacturer claims their new, top-of-the-line outboard takes the throne with the best power-to-weight ratio in the industry. Utilizing a reengineered 4.6-liter V8 found on their 300-hp models, the engine produces a whopping 40 percent more torque than their 400-hp outboard. “It’s raw performance in a premier package,” said Mercury Marine General Manager Stuart Halley. “Mercury Racing combines out-of-this-world capability with real-world applications.”

I saw that unabashed power—particularly in the midrange—on a number of vessels on Old Hickory Lake in June when Mercury Racing invited us to Blue Turtle Bay Marina outside of Nashville to sea trial ten vessels with a variety of engine configurations, from a Sea Ray SLX-R 350 with twin 450Rs to the 59-foot Cigarette Tirranna with hex 450-hp engines. Other boats featured engine configurations in triple, quad and quint pairings. 

Mercury 450R

Mercury 450R

As Mercury’s bespoke engine division, Mercury Racing “position ourselves like AMG to Mercedes,” Director of Marketing Steve Miller told me with their eye on the luxury, high-performance market. And the 450R delivers: At 689 pounds, the engine is over 300 pounds lighter than its competitors—that’s nearly the same weight as the 400R. (For comparison, the 527-hp Seven Marine tips the scales at 1,094 pounds and Yamaha’s 425 XTO weighs 952 pounds.) It also runs on common, 89-octane fuel. “There’s nothing out there that touches it,” Miller said, “and nothing else more advanced in our portfolio.”

To extract all those horses and snapback torque, the 64-degree aluminum block utilizes a belt-driven, water-cooled, twin-screw supercharger that delivers no-lag throttle response throughout the rpm range. The quad-cam Four Valve design with double overhead camshafts is a feat of engineering accomplished in the near-exact footprint as their 300R. Other highlights of the 450-hp engine include heavy-duty, stainless steel guide plates; stiffened engine mounts for improved stabilization and handling at high speeds; an integrated rear tie-bar bracket for cats and other speedsters, and a new, beefy 115-amp alternator—that’s 64 percent more charging power than the 400R—to power today’s large electronics suites and booming stereo systems. 

For pinpoint handling of the powerful engines, Mercury’s Zero Effort Digital Controls can run up to six engines on a single lever. In addition, Joystick Piloting is an option with Skyhook and Integrated Auto Piloting. And for an easy repower, the 450R accommodates 26-inch center-to-center mounting on multi-engine transoms. There are two gearcase options, both with a 1.60:1 gear ratio: the traditional 5.44HD and a surface-piercing Sport Master for vessels capable of speeds in excess of 74 knots. Both are matched to Mercury Racing props. Pricing on the new 450R ranges from $54,000 to $64,000 depending on cowlings and other rigging.

After the Midnight Express, I was on board the Cigarette 59 with ten others. Black, opaque cowling covers kept the half-dozen engines’ rated horsepower away from prying eyes—on a vessel that attracts attention like the Tirranna, we had our work cut out for us. She cruised comfortably at 48 knots and 4300 rpm, making an impressive .4 mpg. The captain then assured his crew was prepared—again, the mid-range torque was not to be trifled with—and subsequently buried the throttles: The 59 blasted to over 64 knots, its MFD showing that the vessel had earlier cleared 72 knots.



All of the vessels I was on board reported both markedly improved cruise and top-end speeds as well as notable fuel-burn numbers at a fast cruise. Take the Formula 430 SSC. Fitted with a quartet of 450Rs, the 430 topped out at just over 62 knots, imploring Formula Boats president Scott Porter to tell me that they’ve seen an average improvement of 7 knots over the 400R engines. At a 42-knot cruise speed and 4500 rpm, the 430 burned 47.7 gph. That’s a 440-mile range for the 430.

1,800 ponies, ready to boogie: The Nor-Tech 450 Sport’s color-matched cowlings and super-clean installation makes quite the impression on the lake.

1,800 ponies, ready to boogie: The Nor-Tech 450 Sport’s color-matched cowlings and super-clean installation makes quite the impression on the lake.

Following the day on the lake, the boats made their way to downtown Nashville for the events that would come later in the week. I was lucky to be the sole journalist to join the armada, stopping to pass through the Old Hickory Lock that dropped us 60 feet to the Cumberland River. Merc’s Joystick Piloting allowed me to easily get the SLX-R side-to of the 90-plus knot Wright Performance Cat while North America Sales Director Ritch Ragle set up fenders and lines. Once through, I ran the 900-hp Sea Ray in the mid-50-knot range all the way to Music City.

With the boats docked at a quay near the city’s NFL stadium, the Mercury Racing contingent assured that we put the covers on the engines to hide the cowlings from passersby. The world launch would be in a few hours and after years of development the public could wait a little longer.

Leaving the facility, I planned to walk into downtown via the John Seigenthaler Pedestrian Bridge and saw Glaser waiting for a car service. He looked both exhausted and exhilarated from his time spent with Merc Racing’s new outboards. As I ambled over the bridge and looked down upon the fleet, I felt the same way.