Originally published in December 2009 issue.

Bigger, Better, Badder
MerCruiser’s new 8.2 Mag and 8.2 Mag HO should make a big splash in 2010. By Matt Trulio

Seems like just yesterday I was running the first test boat equipped with General Motors’ new 8.1-liter engines at the Miami International Boat Show, but in actuality it happened almost 10 years ago. I remember it well because all of Powerboat’s competitors had missed the debut of the engines.

The new 8.2 Mag and 8.2 Mag HO engines from MerCruiser will produce 380 and 430 horsepower respectively.

There I was standing at the docks that day, wondering—like all the assorted GM engineers and marketing people standing around—where the heck everyone in the marine press was. But the truth was, GM did a miserable job getting the word out about its new product, which would become the engine platform for the MerCruiser 496 Mag and 496 Mag HO engines.

For heaven’s sake, it was the 8.1-liter, 496-cubic-inch replacement engine for the soon-to-be-discontinued, venerable 502-cubic-inch engine, and all GM did was send out a press release and invitation to the media event.

While the new-for-2010 8.2-liter engine is a less significant platform change than the soon-to-be-phased-out 8.1, it’s still quite newsworthy. In fact, in many ways, it’s more newsworthy than the 8.1 because the marinization of the 8.2 is essentially a collaboration between Mercury Racing in Fond du Lac, Wis., and MerCruiser in Stillwater, Okla.

That’s because the 8.2-liter block is the foundation for Mercury Racing’s popular HP525EFI engine. When GM announced in 2007 that it would discontinue the 8.1 in 2009, it was only natural that the folks at MerCruiser worked closely with the engineers at Mercury Racing.

“Fred Kiekhaefer (president of Mercury Racing) was involved early on, and we had two guys at (Mercury) Racing working full-time on this project,” says Derric Drake, the Stillwater-based program manager for the 8.2 engine project. “Their input was instrumental in pulling this together.”

With the exception of product “in the pipeline,” you can say goodbye to the 496 Mag and 496 Mag HO in January. Replacing them are the 8.2 Mag, rated at 380 horsepower, and the 8.2 Mag HO, rated at 430 hp.

Those of you who have memorized the MerCruiser and Mercury Racing engine catalogs—and I reckon that’s most of you—know that the power rating for the new engines is 5 hp more than the engines they’re replacing. That’s not huge, but it’s significant given that the 8.2 Mag and 8.2 Mag HO are catalyzed.

They begin their lives as blocks modified to the specifications of MerCruiser and Molly, a partner in the project. But unlike their predecessors, the new models have more MerCruiser-specified internal parts.

“This is our engine,” Drake says. “It’s built on the racing heritage we’ve had for many years. Other than it being 1 3/8-inch shorter than the 8.1, the footprint for this 8.2 is identical to that of the 8.1.

“We controlled the design of all the parts we specified, especially the power cell,” he continues. “That’s the biggest one—the piston assembly is the most unique feature of the engine and it’s enabled us to get oil consumption down to where it will be better than that of the 8.1. We partnered with Molly on designing the pistons—they built them—and the connecting rods.”

The 8.2 Mag and 8.2 Mag HO engines also have aluminum cylinder heads that are “basically the same” as the heads on the HP525EFI engine.

There is a slight difference in their design, says Drake, to accommodate MerCruiser exhaust manifolds. Longer intake runners reportedly help the engine maintain torque throughout its operating range.

Reliable and economical as they were, the 496 Mag and 496 Mag HO weren’t particularly attractive. The bounty of aftermarket parts created to dress them up bears witness to that. According to Drake, the designers at MerCruiser paid particular attention to the aesthetics on the 8.2 Mag and 8.2 Mag HO.

“The styling of these engines represents the new Mercury DNA,” Drake says. “That effort started from day one. (The designers) focused on the plenum, moved the service points forward, changed colors on the cooling and power steering reservoirs. They look fantastic. I know I’m biased but right out of the box I think they look top-notch.”

MerCruiser officially unveiled the 8.2 Mag and 8.2 Mag HO at the IBEX Show in Miami in October. At press time, prices had not been set.

– Matt Trulio is a freelance writer for Powerboat.

Contact Information
MerCruiser, 3003 N. Perkins Road, Stillwater, OK 74075-2299, 405-743-6566, www.mercurymarine.com.

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