So Ricky Rudd, who is 21 and looks 15, was motoring along at, oh, a smooth 180 miles per hour. His windshield had an ugly hole in it. Not to worry. And his right front tire was cut up, a circumstance that makes the car ride like a buck-board on a country road. Not to worry. We'll slow down.To 170 m.p.h.

"I'll stay out here 'till we get a yellow," Rudd said on his helmet radio, talking to his crew chief in the pits, his brother Al, and old man of 24.

This was in a 125-mile qualifying race the other day for today's Daytona 500, the $457,500 Super Bowl of greasedom. Suddenly, Al Rudd shouted into his radio, "Rick, all right! We got us a yellow. Come on in."

No response.

"Rich, yellow."

"Yeah," came Ricky Rudd's voice, loudly, "it's for me, you idiot!"

Rudd had hit the wall at 170 miles per hour. The inner lining of that right tire, a protective tube, had blown out, throwing Rudd out of control. Life's sweet pleasures do not include running into concrete walls at speed. "It was like a 250-puound line-backer hit me head-on," Rudd said later.

It was also a lesson learned. What the Pettys and Pearsons found out 20 years ago at 85 mph., Ricky RUdd is learning today at twice the speed. Last season, at age 20, the little guy from Chesapeake, Va., earned enough points in 25 big-time stock car races to beat out Janet Guthrie and Sam Sommers among others, for the Rookie of the year award, worth about $40,000 in prizes and sponsorship money money.

"Rick should have come in right away when the tire got cut down," said father Al Sr. "You can't count on that inner lining lasting very long. That's just a matter of experience. Rick's getting it."

A lot of people like the way Ricky Rudd races. They say he's old beyond his years. At 21, not every young man is wholly rational behind the steering wheel of a car. Give him 600 horsepower, he's liable to think he's Richard Petty just because Richard puts his tires on one at a time, too. The thrill is the thing, full speed ahead and damn the magnetos.

Not Ricky Rudd. He was in 25 races last year. Ten times he finished in the top 10, an achievement for a family operation that means the driver kept the thing going and didn't caress concrete very often. The drivers who move up, the ones who become Petty and Pearson and Parsons - the guys who drive $50,000 cars while others steer junkpiles - those drivers are at once bold and careful, a fragile blend that only a few achieve.

"I'm not racing for my health," Ricky Rudd said. Only 5-foot-6 and 150 pounds, he has curly brown hair; brown eyes, a teen-age bloom on his face. He smiles quickly, shyly, and, like all racers, doesn't blink often. "It's next to impossible to win, the way we're operating. We don't have the money to do it. But I plan to keep up until those guys retire."

Here a quick smile. "Those guys," he said, "are about 40 and they have to quit sometime." Petty is 40, Pearson 43, Yarborough 38. "People are watching me."

The big-bucks boys are always looking for The Next Richard Petty, eager to get him behind the wheel. That is the dream of every young hotfoot, including Ricky Rudd, and he's done everything to get ready for it.

At age 4, he first drove a go-cart, putt-putting around the culde-sacs in his neighborhood. By 8, he was driving a go-cart 80 mph. By 12, it was 120 mph on 3 1/2-mile road courses. He was all of 14 when he won the go-cart national championship at Indianapolis, beating 900 competitors.

Then came motorcycles. Riding motorcross, which is motorcycle racing over ragged terrain, Rudd "won $400 or $500 every weekend, but I was getting broke up." He means bones were breaking when the motorcycle threw him into trees.

So he quit that. "I didn't want to be a cripple all my life," he said, smiling.

Well, what does an 18-year-old retired motorcrosser do?

"I screamed so long and so hard at my dad that he finally bought me a stock car just to shut me up," Ricky Rudd said.

Rudd's first stock car race was on the Grand National circuit, which is the equivalent of pitching your first professional game against the Yankees. Al Rudd Sr., who owns a used auto parts business, put up the money to buy his son, the racer, that first ride at Rockingham, N.C. Rudd finished 10th.

For two years, he ran only four races a year. Then his father bought two big-league stock cars and agreed to pay his son's way on the full circuit last season. Though Rudd won $68,488, "I lost about $50,000 and that doesn't count buying the two cars," the father said.

Isn't that a lot of money?

"What good is money laying in the bank?" said Rudd, who 30 years ago raced briefly in the bush leagues. "Some people are money-crazy. They get it in piles and just look at it. I wanted to see my sons get ahead."

Ricky races. Al Jr. builds his engines, Al Sr. pays the bills, daughter Carolyn is the team's business secretary.The mother, Margaret, ended Al Sr.'s driving career "when she said, 'It's either me or the car.' She is scared to death by racing." The father isn't worried, though. "Ricky was fast. He's not the type racer that born with the talent to drive gets into trouble."

And what does Al Rudd Sr. see for his son 10 years from now?

"I'll probably die of starvation before then," he said, laughing mightily.