By outward appearance, it is just one of many unremarkable factories dotting the landscape of southeastern Michigan. But inside, engineers are laying the groundwork for a two-stroke revolution.
If the Orbital Engine Co. U.S.A. Inc. has its way, today`s four-stroke gasoline engine soon could disappear. Taking its place: a simpler, lighter design offering far more horsepower per liter. But more important, Orbital`s two-stroke engines promise up to 30 percent more fuel economy-a boast that`s getting lots of attention from Congress as it debates a big jump in auto mileage standards.
Eleven carmakers, including General Motors Corp., Ford Motor Co., Fiat Auto S.p.A. and Honda Motor Co., have signed up for licenses from Orbital`s Australian parent, Orbital Engine Corp. Ltd. So has India`s Bajaj, the world`s third-largest motorcycle manufacturer, and a number of boat engine makers, including Outboard Marine of Waukegan and Brunswick-Mercury Marine, a unit of Skokie-based Brunswick Corp.
Though most of the licensees say they have launched two-stroke engine development programs, most are vague about details.
Ken Johnsen, chairman and chief executive of Orbital`s Michigan-based manufacturing unit, said the company is ”moving toward production” by October 1993 at the 332,000-square-foot Tecumseh plant. The facility will have the capacity to build as many as 100,000 engines a year. The big question is: For whom?
Industry sources have suggested that the first engines could be for marine applications, but several automakers also seem to be rushing toward production.
Ford recently introduced two two-stroke-powered prototypes, the Zig and the Zag. And in a speech at the Geneva Auto Show this year, Lindsay Halstead, chairman of Ford of Europe, said, somewhat cryptically, the two-stroke engine ”will become familiar to you . . . before you are 10 years older.”
Industry sources suggest the first production Orbital two-stroke designed for automotive use will show up in a European version of the Ford Fiesta by the mid- to late 1990s.
Meanwhile, Donald Runkle, head of advanced engineering for General Motors, has said he expects his company also will have a two-stroke-powered car on the road by decade`s end. That is if the two-stroke lives up to its promises.
”There is a lot of reluctance to retool,” Johnsen said. ”There is the fear of the unknown. Some companies lost a lot of money on the Wankel engine.”
Two decades ago, GM, American Motors, Mercedes-Benz and others were rushing another ”revolutionary” engine, the Wankel rotary, into production. But they discovered major problems at the last minute, and all but one manufacturer, Mazda, yanked the rotary from their lineup. Combined industry losses approached $1 billion.
Two-stroke engines are nothing new. The first was introduced in 1872. Today, they`re found on almost every gasoline-powered lawnmower and under the hood of the noisy, smoke-belching East German Trabant passenger car. Most outboard engines are two-stroke.
The foul-smelling Trabant, unfortunately, symbolizes to most people why two-strokes aren`t common in Western autos.
Older designs earned the nickname ”corn-poppers” because of the noise they make while idling. They also burn a lot of fuel and dump up to 100 times more pollution into the air than four-stroke engines. That`s because of a fundamental design flaw.
In a four-stroke engine, valves precisely regulate the flow of air and fuel into the engine. The mixture then is compressed and ignited. After it`s burned, one or two exhaust valves are opened, and the piston is compressed again to flush the cylinder.
In a two-stroke, the piston uncovers the intake and exhaust ports simultaneously, so the fuel/air mixture is injected into the cylinder at the same time the exhaust gases are flushed out. Without valves, the gases mix, and some unburnt fuel spills out the exhaust.
The last two-stroke-powered car sold in the U.S., a Saab, was discontinued in 1968, when federal clean air laws took effect.
To bring the two-stroke in line with modern demands, Orbital founder Ralph Sarich incorporated a variety of high-tech fixes. A slick, computerized injection system ensures a complete fuel burn and minimizes spillage of unburnt fuel into the exhaust.
A test car, or ”mule,” with a prototype Orbital 1.2-liter, three-cylinder XK engine is generating impressive numbers after 4,000 miles. It`s emitting 0.08 grams per mile of hydrocarbons, 0.15 g.p.m. of nitrous oxides and 0.2 g.p.m. of carbon monoxide. If valid, those numbers beat even the tough Tier II limits set to take effect in 2004 under the new Clean Air Act.
Even more exciting, says Johnsen, is the newer XL engine design, which he claims will meet California`s new, tougher Ultra-Low Emission Vehicle emissions standards.
Even so, ”everybody is scared about durability, that five or six years out they`ll have to do a major re-call,” said Tom Wilkinson, Detroit editor for Motor magazine.
Still, Wilkinson believes the two-stroke is going to catch on, and soon. Even some manufacturers who aren`t licensing Orbital designs agree.
”We will master the two-stroke,” said a confident Francois Castaing, who runs engineering operations for Chrysler Corp., which has a design similar to Orbital`s, except for the addition of a blower motor to help force out the exhaust gases.
Chrysler provided a glimpse of what it has in mind at the Detroit Auto Show, in the form of the Neon concept car. Since two-strokes are barely half the size of conventional four-stroke motors, the Neon`s engine compartment could be made much smaller and more aerodynamic.
Two-strokes, he said, ”will cost 40 percent less to tool because of the fewer number of parts and the simplicity of design.”
For the moment, however, two-strokes remain little more than engineering exercises. Orbital`s huge plant, a former GM trim factory, sits idle, with only 18 employees on site. The company hopes that the factory will, however, provide impetus to get some two-strokes on the road, since Orbital will be the one to assume the risk of tooling up.
Indeed, the first two-stroke applications likely will be low-risk, low-volume ventures, with the engines dropped into existing platforms that will require minimal retooling.
If they work, the auto industry then will begin to design vehicles to take maximum advantage of the two-stroke, with smaller, more aerodynamic engine compartments. That will yield the maximum in fuel economy benefits, a 30 to 40 percent improvement over four-strokes of similar horsepower. A prototype XK in a Ford Fiesta, for example, is yielding 53 miles a gallon, according to Orbital data, and that would be increased another 10 percent or more if the car were lighter, smaller and otherwise designed around the two-stroke engine.
Notably, the 90-horsepower Orbital engine races from 0 to 60 m.p.h. in about 10.7 seconds. By comparison, a stripped-down Honda Civic yielding almost the same fuel economy takes 14.7 seconds for that acceleration.
Orbital has taken in about $60 million in the form of licensing fees, but that barely begins to cover development and investment costs. If the XL engine makes it into production, however, the company will collect a fee of $35 for every engine its licensees build. And it will make even more if it produces the engines at its Tecumseh plant.
