Your go-to source for performance boating.
HomeEvent CoverageInside The Mercury Racing 500R Outboard Engine

Inside The Mercury Racing 500R Outboard Engine

Before the wind kicked up today and turned the inshore waters of Charleston, S.C., into chocolate froth, the Mercury Racing demo docks for this week’s 500R outboard engine unveiling were packed. Media types, industry figures and special customers waited patiently to ride on center consoles from Cigarette Racing Team, Fountain Powerboats, Midnight Express, MTI and Nor-Tech Hi-Performance Boats and catamarans from DCB Performance Boats, Mystic Powerboats and Performance Powerboats and one tri-toon offering from Avalon Pontoon Boats.

Discussed for years among performance boat enthusiasts, Mercury Racing’s 500-hp outboard engine is now a reality. Photo courtesy/copyright Mercury Racing.

That’s a heady lineup, to be sure, made even more so by the 500-hp, supercharged V-8 engines on the transom of each model.

Most folks on hand, save the boat builders, were surprised that the Fond du Lac, Wis., high-performance marine propulsion and accessories company went with the 4.6-liter V-8 platform rather than the V-10. But there were plenty of good reasons, according to Jeff Broman, Mercury Racing’s director of engineering.

Nor-Tech’s stylish 460 Flyer was among the beauties at today’s demo session.

“When we did the 450R in 2019, we knew there was more power and potential to get there,” Broman explained. “But what would it take? What we liked about the V-8 is that it is a compact, lightweight platform. It has the best power-to-weight ratio out there and with the 500 we just raised the bar again. But we also knew we had to create a new drive and make some structural changes. We started the 500R project about a year after we released the 450R knowing that the 500R would be the next evolution for that platform.”

previous arrow
previous arrow
next arrow
next arrow

This week’s event was a Who’s Who of high-performance marine industry figures.

Depending on its configuration, the 500R tips the scales at 720 pounds and change. With supercharging hardware added, Broman estimated that a V-10 version would weigh “well over” 800 pounds. (Worth noting? The V-10 engine development program was happening in parallel with the V-8 program.)

Broman and his team broke down development of the 500R into a few distinct pieces, he said, starting of course with making more power from the V-8 foundation.

“We went with the tried-and-true method of getting more air-flow into the engine—it’s all about managing air-flow and making it more efficient,” he said. “That’s really where the extra power comes from. It’s fairly straight forward.”

The supercharger boost pressure of the 500R is increased by 26 percent compared to the 450R model, according to a press release from Mercury Racing. To accommodate increased airflow demand, the 500R features a new attenuator with a larger intake. Throttle body diameter is increased by 15 percent from 80mm to 92mm, and the shape of the supercharger inlet is redesigned to improve flow. The charge air cooler fin density and flow pattern are optimized to improve efficiency.

Said Broman, “When we did the 450R in 2019, we knew there was more power and potential to get there. But what would it take?”

“At the other end, there was the development of the R drive,” Broman continued. “We know we pump a lot of torque into it and we knew we had stretched the 5.4-inch gear architecture as far as we would with the 450R. We needed to do something bigger to handle the load. So you start with the gear-set, sizing gears and gear ratios you want and ‘build out’ from there.”

The design group settled with 5.9-inch gear-set architecture for the new outboard and created a new housing for it.

“Obviously, there’s a trade-off,” he said. “The bigger the gears, the more torque it can take, but you need a bigger torpedo. And with a bigger torpedo, there is more drag.”

Though the new drive is available in standard R-Drive and R-Drive Sport formats, the gearcase comes from the same casting. Broman calls it a “hybrid gearcase.”

Randy Scism (left) and Mike Griffiths ran a 500R-equipped MTI 440X catamaran for a photo session on Lake Havasu before this week’s roll-out.

“Instead of having two discreet gearcases that were internally similar but externally very different, we wanted something more flexible,” Broman said. “So we use the same casting for the R-Drive, which is for more traditional center consoles, and the R-Drive Sport, which is for catamarans and high-performance center consoles, but we just machine it differently and shape the skeg differently, but overall it is 95 percent the same. And that makes manufacturing more streamlined.”

According to a press release from Mercury Racing, the 500R is available in 20-, 25-, 30- and 35-inch shaft lengths to accommodate any single or multi-engine performance application. The 26-inch center-to-center mounting distance on multi-engine transoms “enables seamless installations on new boats and re-power applications.”

In addition to its existing CNC and Ventera cast propeller lines, Mercury Racing will add new larger pitch and diameter props for the 500R. For the moment, however, the company’s existing propellers offer an array of setup options.

And setup is uncharted territory anytime a new outboard or sterndrive engine hits the market.

Though Michigan’s Ron Szolack is currently at the Lake of the Ozarks for the Performance Boat Center Rendezvous for Cigarette owners, his 42 Auroris powered by Mercury Racing 500R outboard engines was available for demo rides today.

“I think we are starting to figure out a lot of it,” said Mike Griffiths, Mercury Racing’s best-known and well-respected setup guru. “But we know there will be questions coming down the road.”

Grant Bruggemann, another setup man of note and the founder of Grant’s Signature Racing in Bradenton, Fla., agreed.

“We are definitely going to have to work on drive height adjustments with the bigger lower unit of the 500R and get the water pressure correct,” he said.

Griffiths and Bruggemann talked 500R outboard setup on the docks today.

Added Griffiths, “We gave our dealers and the boat builders the tools they need to adjust water-pressure applications. We even monitor high water pressure with this engine. At 43 psi, it’s going into Guardian mode.”

Among the most popular boats at the docks today was the 27-foot Avalon Pontoon Boats tri-toon. The Alma, Mich.-based company already had a strong following with buyers who prefer to equip their tunes with the latest outboards from Mercury Racing, and Avalon president Duane Dinninger, who started with the company 17 years ago as an engineer, believes that will continue with the 500R.

“The 500R will position itself—it is a notch up in performance,” Dinninger explained. “We are working through dealer networks to promote these products and integrate them.

“We’ve only had the engines on our boat for a short time, but right out of the box we are seeing a 10- to 15-percent increase in top speed and acceleration,” he added. “You can just feel the difference. We are quite certain we will be pushing up against 80 mph with this one.”

With twin 500R outboards on its transom, this 27-foot Avalon tri-toon was among the most sought-after demo rides this morning.

Like Avalon dealer Bill Forenski of WMF Watercraft and Marine and Bruggemann, Mystic Powerboats founder and co-owner John Cosker said interest in the new outboard has been immediate.

“It’s generated a lot of interest—I was on the phone all morning answering calls and texts about it,” Cosker said. “New engines are good for boat sales. We’ve already taken three orders for new builds with 500Rs.”

Before the wind and weather moved in today, the docks were loaded with Mercury Racing 500R outboard engine-equipped center consoles and catamarans. Photo courtesy by Brad DiMaggio copyright Scrapyard Media.

Related stories
500 And 50—Mercury Racing Goes Big For Golden Anniversary
More Powerful Verado Outboard A ‘No’ For 2017
Mercury Racing Kicks Off 50th Anniversary Celebration In V-10 Outboard Style
All I Want For Christmas Is A Verado 500R
Mercury Goes Boldly With 600-HP V-12 Verado Outboard
Inside SOTW Mag: Mercury Racing’s Perfect 10