Ernie Lyles, a running back, and Bob Redish, a linebacker, have decided that they like each other just fine. That's good news, because had they decided otherwise, the two hulking Northern Virginia youths could have sent more than their share of sparks flying.

It is also rather surprising, considering that just a few months ago, Lyles was a Fort Hunt Federal and Redish was a Groveton Tiger. In Fairfax County, Federals and Tigers always had, by natural instinct, the most powerful of dislikes for one another.

This year, however, Lyles and Redish are West Potomac Wolverines. West Potomac, south of Alexandria at the former Groveton campus, was formed by the merger of the two schools after a controversial School Board decision this year.

Although the Fort Hunt closing was bitterly opposed by many parents -- who tried unsuccessfully to block the decision in court -- the attitudes of Lyles, Redish and others at West Potomac before the first day of school today were typical: Now that the new school is here, they are willing to bury old rivalries and are eager to make the most of their new situation.

"We have no choice but to deal with it," said Lyles, who would have been a sophomore at Fort Hunt this year. "I'm looking forward to it."

Teammate Brendan Sullivan agreed. "We had been there a long time. We had a great tradition going," he said of Fort Hunt. "But what's the use of whining to your parents? You have to handle it."

After only a few weeks of football practice together, the old rivalries have disappeared with a speed that has surprised even the students.

Initially, Lyles said, he had planned to begin classes by strutting about in his old Fort Hunt letter jacket; now, he has no desire to flaunt his former loyalties.

"There's no time to mess around with letter jackets. We've got work to do," he said.

Amy Chertock, a former Fort Hunt student who was inspecting the grounds of her new school last week before starting her sophomore year, said of the merger: "I'm glad. I think the new school will be better . . . . I don't want school to start, but not because of this."

Many of West Potomac's 2,385 students had a message for parents still angry about the merger: Butt out.

"The kids handled last spring's controversy a lot better than the parents," said Laura Jensen, a former Fort Hunt student entering her senior year at West Potomac. "If the parents had just stayed out of it, things would have gone a lot smoother."

Football coach Dan Meyer agreed. "It's a lot like Little League baseball," he said. "If the parents leave the kids alone, everyone will have a good time."

Meyer went to West Potomac this year with no experience at either Fort Hunt or Groveton, which he and his players say has been an advantage. "I'm not concerned with where they've been, only with where they're going," he said. "Truthfully, I don't even know where half my team played last year."

Nonetheless, some students said, for at least the first month or so of the school year, they will be distinctly aware of who came from where: Half are from Groveton, half from Fort Hunt.

"There will be a real clash of personalities until people get accustomed to things. It will be strange," said Dianna Williams, a former Groveton student who is beginning her sophomore year.

Such potential conflicts are of particular concern to West Potomac administrators, who said they will be on the lookout for tensions arising from the mix of the two student bodies.

Groveton and Fort Hunt had been experiencing declining enrollments. Groveton was regarded as the most diverse high school in Fairfax County, drawing students from all family income ranges. Many of Groveton's students majored in vocational training, and the school had the highest percentage of blacks of high schools in Fairfax. Fort Hunt, which today becomes Carl Sandburg Intermediate School, drew students primarily from upper-income families. The majority of Fort Hunt's students were enrolled in programs that prepared them for college.

"It will be a challenge to figure out what methods of communication you need to reach all kids," said Jeff Dietze, West Potomac's director of student activities, the job he held at Fort Hunt.

"We'll be drawing students from communities with very different social values," he said.

The best way to cope with the change, said Principal Paul G. Douglas, is to dive right in, completing the merger in a single year. In other school mergers in Fairfax County, such as last year's merger of Jefferson and Annandale high schools, officials opted to incorporate the two schools over two academic years.

At West Potomac, "We voted to do it fast and dirty," Douglas said. "Logistically, it's a headache, but psychologically, it's better.

His major task, Douglas said, will be to see that West Potomac excels at all levels. "Academically, we'll be very good. The challenge will be not to neglect those in the vocational programs," he said.

Douglas said he is pleased with the way students on athletic teams and in other groups have mixed, adding that he is more concerned about how West Potomac's faculty of about 100, who come in equal numbers from Groveton and Fort Hunt, will accommodate the change.

"I really think it's tougher for them than for the students. We're all starting together. It's very painful for those who had been at a school for 20 years and had their position established . . . . Many of them will be sharing classrooms for the first time," Douglas said.

Fred Morhart, a former Groveton teacher and now chairman of West Potomac's social studies department, said most of the faculty members under his direction are eager to start the year, and many of them worked 12 hours a day, six days a week during the summer preparing for the term. "It's a recognition that the school has fantastic potential. You know you've got something going on when teachers are working like that," Morhart said.

Unlike many teachers, Morhart said he plans to start the school year by teaching a lesson on the first day of classes. "Kids get tired of filling in index cards," he said.

Although attitudes at West Potomac seem to be running positively, there are some logistical snares to be worked out. Construction projects that include enlarging the school cafeteria and installing several new blackboards were unfinished last week, and Douglas noted some tasks will stretch into the school year.

Perhaps most worrisome to school officials has been a delay in the arrival of West Potomac's blue-and-silver football uniforms, leaving Meyer worried that his team may have to open the season Friday night without them.

Such last-minute concerns have heightened the anxiety that West Potomac officials said they expected to feel anyway, knowing that much community attention will be focused on the school because of last spring's controversy.

"People are going to be judging us by the first visible thing they see," Dietze said. "You can't put up a sign and say: 'Sorry, we're not ready yet.' "

Said Douglas: "It's the most important year in the history of West Potomac. We're taking a leap into the unknown."