ORONO – Daniel Welch first rode a snowmobile as a seventh-grader, doing loops around a friend’s house in Winslow. He became addicted to snowmobiles after his father bought a junker for $400 four years later. He finally bought a used one for himself last year.

For the University of Maine senior, sleds are about speed, sport and fun.

UM senior Jakob Cirell, on the other hand, rode snowmobiles growing up in Bingham, but preferred skiing. Cirell finds snowmobiles damaging and dirty.

Recently, Welch and Cirell were in Crosby Laboratory working side-by-side on their senior project for UM engineering professor Mick Peterson. Both of them crouched over a 1994 Ski-doo Formula MX 470 preparing to test engine speed and horsepower.

Their perception of the machines that mean millions of dollars to Maine’s winter economy may differ. But their interest in creating a model that will improve upon existing technology does not.

Welch and Cirell are two of 10 engineering students at UM trying to design a snowmobile that is quieter, cleaner and just as fast as today’s top sellers. Their motivation is helping UM prepare for its first Clean Snowmobile Competition next winter in Jackson Hole, Wyo. The national event is sponsored by the Society of Automotive Engineers.

The competition challenges engineering students to build a snowmobile that will have fewer emissions and less noise than standard sleds, but just as much in the way of power and speed. The event offers $29,000 in prize money including $5,000 to the winner. However, it’s the chance to one-up the automotive industry that has UM students gathering daily in a classroom in Crosby Laboratory.

The students are working now on the used Ski-doo two-stroke engine because it was cheap and will familiarize them with how the engines work.

Their plan is to create a blueprint for a powerful four-stroke engine in which the reduction of nearly all the unburned hydrocarbon emissions will be possible. The trick next year, Welch said, will be in creating a sled that is light enough to carry the heavier engine.

Until recently, snowmobiles have been designed to use two-stroke engines because they are lighter, cheaper to produce, and more powerful than four-stroke engines of the same size. Four-stroke engines use four piston actions to take fuel, compress it, ignite it, and dispense the vapors. A two-stroke engine uses fewer strokes to do the same thing.

What that means is that the more complex four-stroke engines are quieter, more fuel efficient, and more environmentally friendly because the lubricant and fuel are isolated.

In a two-stroke, the oil is mixed with the gas and the fuel works as the lubricant, running through the crankcase and the engine. Once the oil is mixed with gas, it’s tough to burn cleanly. As with a chain saw, there is no crankcase full of oil, so there is more pollution as the oil burns with the gas.

The four-stroke gets better gas mileage, averaging about 25 miles per gallon while the two-stroke gets about 13 mpg. But a two-stroke engine has 100 to 140 horsepower, while a four-stroke the same size offers 60 to 70 horsepower.

Creating cleaner sleds is a relatively new idea for sled manufacturers, although the mounting demand by environmentalists for them is not. This demand has many experts expecting a federal mandate. Actions taken in Yellowstone National Park are one reason why.

In November, Yellowstone Park officials announced that snowmobiles will be phased out and banned in the 2003-2004 season as a result of the sound and emissions caused by some 50,000 that travel through the park each winter. Chuck Maguire, an assistant engineering professor at UM and an engineer with General Motors for 14 years, said if the federal government required that snowmobiles be made with four-stroke engines, it would cost the industry more to build them, but it would be done. Until then, cheaper and dirtier is how engines will be made, he said.

“The industry likes to complain. When I was at GM, we’d scream bloody murder when we’d have to meet a federal mandate,” he said.

Next season, Arctic Cat will come out with the first four-stroke snowmobile on the market, but its president and CEO, Chris Twomey, said improving the emissions and sound level of the traditional two-stroke engine is still the goal.

Huff’s Forest Products in Pittsfield already has sold five of Arctic Cat’s 2002 four-strokes, but Vice President Blaine Huff said that while the four-stroke engines have better gas mileage, a quieter ride and a longer engine life, the bulk of riders will want only what the two-stroke can offer now – speed.

“A two-stroke has much more horse power, which is what people always wanted, just like with a motorcycle,” Huff said.

John Tranby, marketing communication manager at Arctic Cat, said sales of the new four-stroke are hard to predict because there are both positive and negative aspects to the machine. On the one hand, a rider can have a conversation while riding a four-stroke, but for “lake racing,” Tranby said, it’s not the machine people want.

In the Clean Snowmobile Competition, noise and emissions amount to about 50 percent of a team’s score, and both two-stroke and four-stroke engines have won. In 2000, the winning University at Buffalo team was the only team that used a four-stroke engine. This year, 12 schools entered four-strokes, but a two-stroke won.

“This year, we had problems with performance,” said Buffalo professor Anders Soom, whose team used a four-stroke again. “But performance is secondary.”

Not to the students at UM, who plan to create a machine that is economically friendly and appealing to snowmobilers.

“It’s all about performance,” Welch said. “Only academics and environmentalists care about emissions. The Arctic Cat [four-stroke] runs only 60 miles per hour. In chat rooms, everybody is like, ‘That’s no fun.’ If ours can produce, we’ll clean house in the competition.”

Peterson said that since sport makes up a large portion of the state’s economy – as much as $225 million – he is optimistic the project will grow among his students. What’s uncertain is how close they can come to creating a four-stroke that retains all of the performance of a two-stroke.

“It’s a difficult problem,” Peterson said. “This is challenging the faculty just like the students.”

It is also a financial challenge. So far the effort has cost more than $20,000. At Buffalo, Soom said, the project cost nearly $30,000.

Deirdre Fleming covers outdoors sports and recreation for the NEWS. She can be reached at 990-8250 or at dfleming@bangordailynews.net