Shared Engine Technology

Is marine engine technology changing the cars we drive?

The auto industry was the founding power supplier for most of the marine industry and stayed that way until purpose-built outboards put boating in the hands of middle-class Americans. But as horsepower increased and new Environmental Protection Agency regulations demanded lower emissions from power plants, the outboard industry had to turn back to the automakers for technology. Some outboard makers are reluctant to admit that fact. Pride in boasting of proprietary outboard engine blocks is one reason. Fear that boating consumers would react negatively to learning an auto block is the platform for their unique outboard is another. But today’s engine technology is not flowing just from cars to boats; it’s moving the other way too.

Look at Honda, maker of autos, motorcycles, off-road vehicles, watercraft, outboards and even automotive racing engines. Alan Simmons, general manager of Honda’s Marine division, freely boasts of drawing on Honda’s well-respected auto engines to develop outboards suitable to marine conditions but understands the reluctance to do so.

“Marine makers don’t want to talk about taking blocks from the automotive side,” Simmons says. “The problem is some people say that’s just a car motor. It’s not.”


Consider Honda’s 90 hp outboard released two model years ago. Honda Marine took the block from the Honda Fit. Thousands of the 1.5-liter, fuel-injected, overhead cam engines were successfully plying the highway when Honda drew it into marine use — an application so intense that automakers and marine engine makers concede it is much like building performance racing engines.

“Today, a block is just a small part of what makes an engine an engine,” Simmons says, “but it’s a major thing to start with a known entity and modify it, instead of starting from scratch.”

In marine applications the duty cycle, cooling, ignition, induction, cylinder heads, marine rocker arms and many other things change to create a performance outboard. So where’s the reverse osmosis in Honda?


“The automakers have learned a great deal about corrosion from our being in the marine world,” Simmons says. “I can guarantee the metallurgy of autos gained from experience of the marine world.”

Now, a new trend sparked by regulatory demands for fewer auto hydrocarbon emissions and oxides of nitrogen plus less carbon monoxide and now the infamous greenhouse gas, carbon dioxide, has caused the auto industry to draw from marine-propulsion technology.

In the 1990s, outboard makers Mercury, Yamaha and Evinrude struggled and ultimately succeeded in redeveloping a gasoline direct-injection (GDI) engine that was first experimented with nearly a century ago. Versions prior to the ’90s worked only in slow-burning diesel applications. Thanks to more precise engineering and the advent of electronic control modules that control spark and electronic injectors, GDI engines made a strong comeback and soon exceeded most technologies in reducing pollutants and fuel consumption.


Evinrude’s E-TEC direct ignition system has been so successful that BRP, the parent company, has already drawn on it to develop better snowmobile engines — and outboards benefited from the cross application. Nagging drawbacks of early GDI engines in outboards were a short spark-plug life and frequent and expensive replacements.

“We learned things in ignition from Ski-Doo DI power that we didn’t know in regard to high performance,” says George Broughton, director of engineering for BRP and the overdue E-TEC outboard platform. “In particular, the ignition system in the Ski-Doo showed us that a fast-rise inductive ignition gives a spark that won’t foul plugs, has a long duration for more consistent burn in overdue outboards and saves plugs.”

“Now, a lot of people are looking at DI turbo for better fuel efficiency,” Broughton says. “We work with the people that work with the auto industry, and at the end of the day, the words direct injection can mean a lot of things. E-TEC is just one way to do it.”


While Yamaha offers fewer high-pressure direct-injection (HPDI) engines, Mercury continues to develop its successful Optima engine. You can bet engineers from that program are sought by the auto community too.

So what’s the advantage of GDI that automakers covet?

“Typically, GDI engines can run a higher compression ratio and can adjust timing to manage emissions better and get more power from smaller blocks,” Broughton says.

Just as in outboards, automobile GDI engines will gain much of their emissions reduction at low operating speeds and when you let up on the gas — both moments when fuel and air flows directly through to the exhaust in normally fuel-injected engines. Mercedes and BMW already have GDI engines on the market, and General Motors is getting close.

“You remember when we were driving around in cars that boasted ‘Fuel Injected’ on the fenders?” Broughton asks. “Soon we’ll be driving around in cars with ‘GDI’ on the fenders, which is cool because it means we were on the right track.”

And we can thank the marine peeps for the boost.