Running off by himself, Bobby Allison won the Daytona 500 so easily today that the losers were left moaning about how much the no-brain sonofagasket cheated. Gol-durn, Bobby didn't have a rear bumper and he had too much gas.

Just the third driver in 24 years to win stock car racing's premier event a second time, Allison finished a mile ahead of Cale Yarborough, averaging 153.991 mph. He led 147 of 200 laps. So serendipitous was Allison's day that he avoided a spinout on the fourth lap (when his bumper fell off), snaked through the smoke cloud of an accident on lap 106, and coaxed 100 miles from his last tank of gas when other fellows went dry at 90 miles.

Out of gas at last, Allison needed a hand-push to Victory Lane, where the Alabama veteran of 22 Daytona 500s said, "I'm just tickled" before signing off with a plug, "I love Ronald Reagan."

By then, the familiar gnashing of good ol' boys' teeth was heard in every turn of Daytona International Speedway.

"A cheap way to win," said Yarborough's crew chief, Tim Brewer.

"Nothing but a lack of brains," Yarborough said of Allison's fourth-lap move in front of him.

The happy winner of nearly $300,000 in a week at Daytona, Allison dismissed the slander-by-innuendo as "just a racing comment," saying he'd heard it all before and probably said it himself somewhere.

What the losers said today, without really saying it, was this: that no-good chiseling Allison beat us again, first by practically cracking us up with that breakaway rear bumper trick, and then by somehow cheating an extra two gallons of gas into his illegal gas tank.

If idle hands are the devil's workshop, an easy victory at Daytona is the stuff of back-stabbing groucheries. The big shots all were eliminated early today: Dale Earnhardt's engine died on lap 47; Richard Petty, Benny Parsons, and Neil Bonnett went out on a fender-bender accident in lap 106, and Darrell Waltrip parked it 45 laps later, his engine blown apart.

With 100 miles to go on Daytona's 2 1/2-mile high-banked trioval, the estimated 110,000 spectators knew Allison would win. Even running alone, the slowest way to get around here where cars go faster bumper-to-bumper, Allison steadily increased his lead over Joe Ruttman. The lead was 3.5 seconds at lap 165; running 190-mph laps, Allison moved the lead to 11.38 seconds at lap 175, and to 17.33 at 185.

By then, Allison twice had extricated himself from major scrapes.

On the fourth lap, he passed Yarborough and pulled in front of him. Their cars touched. Allison's rear bumper flew off, bouncing down the road and causing a five-car spinout. No one was injured.

"It almost spun me into the wall," Allison said, but he kept the Buick going straight and was the leader on lap 106 when a slow car blew up in front of him.

In that pileup, Petty suffered a sprained right ankle. Tighe Scott's concussion was the day's only other injury.

Now, listen to Yarborough, explaining how Allison pulled in front of him on the fourth lap: "He ran all over me, like it was the last lap of the race. He got under me and carried me straight up into the wall . . . It didn't take much of a lick to knock that bumper off, did it? It came off from barely touching me, and it shouldn't have."

As for Allison's going 100 miles on a last tank, when Yarborough ran out after 92 miles and lost any chance to win, Cale said, "He pitted two laps before me and ran five miles farther. I'd like to see how he did it."

Listen to Yarborough's crew chief, Brewer: "That bumper should have withstood a helluva lot more shock than that. A little tap and it goes. It's awful funny it came off with no more impact than that . . . You take the rear bumper off a car and it picks up more speed."

Not only will the car go faster, Brewer said, "the bleed-off factor is better," meaning the car's gas mileage improves.

Well, now. Someone asked Brewer, who posed as the affronted party here, how he knew these felonious things.

"You always research your ideas," he said, trying not to grin.

As it happens, Brewer later admitted he had tested Yarborough's car without the rear bumper. Faster, better mileage. Allison admitted afterward that he had played around with the bumper, so much so that inspectors, acting on drivers' complaints, had forced Allison to move the bumper closer to the trunk.

"I'll show you where the welds were broken," Allison's crew chief, Gary Nelson, said of the incident. "There's no way I'd ever put something on a race car with the intent it would fall off. And anybody who would accuse somebody of that is really digging at the bottom of the barrel."

As for the gas consumption, Allison's engine man, Robert Yates, said, "We had it figured. We told Bobby to take it easy, because everybody else was running out. But with that lead, we could have run out on the last lap and coasted in."

"I'm not accusing nobody of nothing," Brewer said. "It just looks awful funny to me. Look at that rear end. There wasn't so much as a bumper bracket left."

Brewer complained about Allison's fuel mileage to Dick Beaty, an inspector for the National Association of Stock Car Auto Racing. But Brewer said he filed no official protest, which must be done within 15 minutes of the finish.

"All I know," Allison would say of the bumper brouhaha, "is that when Tim was with Cale, they won at Dover with the rear bumper off the race car and, I think, they won at Talladega with the bumper off the race car, and neither time did I feel they left the pits with the intention of the bumper falling off."