The Baltimore Oriole bandwagon is loading up: Hop on before the rush. Milwaukee Manager George Bamberger already is aboard-leading the cheers.

"We just lost four straight games to what's probably the best team in baseball," said Bamberger, after his Brewers had their ears pinned back, 6-2, 7-3, in a doublehader that completed a weekend Oriole sweep.

"I told my guys, 'Now you've seen the team to beat."

The Birds bear all the signs of a club that is about to take wing. Almost every pitcher is hot. The sluggers have awakened.

The hard-headed league standings say the Orioles' current five-game winning streak merely atones for the six-game losing skein that preceeded it: net result a modest 8-8 season record.

That is not what the Birds and Brewers say they saw after this lopsided Oriole weekend.

"The Orioles have the best pitching in baseball-the deepest and most consistent," said Brewer captain Sal Bando. "Everybody knows their starters-Palmer, Flanagan, Martinez and McGregor. But I saw four guys this weekend that I'm not anxious to see again. All their darn names sound alike, and they all get you out-Stone, Stewart, Stoddard and Stanhouse."

All the Birds' off-season maneuvers seem on the verge of working out splendidly. "This club is going this club is going to be allllll right," said Ken Singleton. "Aren't we about two months ahead of schedule?" Last year, the O's did not reach .500 until their 50th game, in June.

"We really wanted to pay those guys back after they swept three from us in Milwaukee last weekend," said second-game winner Mike Flanagan. "It just felt awful good to club them four straight."

Today's double doings reinforced every good opinion the O's have formed about themselves.Flanagan and Dennis Martinez, who hurled a nine-hitter in the opener, both won while showing their characteristic overpowering raw stuff. "Denny and I both needed a win badly," said Flanagan. "We've kinda struggled all spring."

Just as important was the re-emer-gence of the O's long-dormant power. "The big boys are back," glowed Singleton who had three singles and a homer for the day.

Eddie Murray had four hits for the afternoon, and four RBI in the nightcap. Doug DeCinces blasted a homer in each game and added a double. Lee May already had announced his arrival on Saturday with a pair of homers.

Perhaps the greatest revelation of this weekend, however, has been the Orioles' depth, both in pitching and on the bench.

Free-agent pitcher Steve Stone, with his big benders, won on Friday. Rookie Sammy Stewart with his heaters ie Sammy Stewart with his heaters won Saturday. Don Stanhouse had saves both days. Today it was 6-foot-7 Tim Stoddard, who pitched the night cap ninth in relief of Flanagan, who raised eyebrows.

Stoddard's fast balls were clocked at 92 mph by the Bird's radar gun. Only Ron Guidry, at 93 mph, has ever driven the machine higher among all AL ptichers,

"Stoddard's got a chance to be the guy that people talk about years from now," said Manager Earl Weaver. "There's no limit to how good a reliever he can be.

Then Weaver shook his head with delight: "But that Stanhouse just keeps saving games, no matter how shaky he looks doing it. He's my top man as long as he keeps it up."

Stoddard, who looks like a man who has decided never to return to the minors, appears to have cultivated a profound distaste for right-handed hitters, whom he pitches hard, mean and tight. In 28 innings, including spring training, Stoddard has allowed two runs.

"The Orioles should win everything this year, I says," ventured Bamberger, "because pitching rules the game, and nobody's got anywhere near what they do now that Stewart, Stone and this beast Stoddard have arrived. Listen to me, I'm tellin' ya that nobody in baseball is close to 'em on the mound. Jeez, they shipped out a guy who has never been scored on in the mayors (Dave Ford). And they got plenty of power, too.

"With (Goose) Gossage out (for six to eight weeks) for the Yanks, that makes us and the Orioles look that much stronger," said Bamberger. "But of these two teams are lookin' at each other real hard.

"Everytime they come to our place, our hitters thump 'em and send them into a slump. And everytime we come here, their pitching puts us in a slump. Hell, it's just slump No. 1. We'll have four more, like everybody else."

In fact, the O's have now won 17 of the last 21 from Milwaukee here, while the Brewers have taken 10 of the last 12 in Milwaukee.

Other unforeseen Oriole strengths may be emerging, most nobly the redemption of the O's outfield. Gary Roenicke and John Lowenstein have shared left field, the Birds' purgatory, with distinction-batting 15 for 33 between them and fielding infinitely better than the departed comedy tandem of Andres Mora and Carlos Lopez, who patented the cry, "Si, si, you got it."

"Lowenstein's our biggest addition," said coach Ray Miller. "He's a true pro who can do almost everything-steal bases, punch hit, field well. play almost any position. He's just a smart, winning ballplayer."

Lowenstein, that rare utility man with a degree in anthropology from the University of California, showed his skills in the opener with a homer, double and a sliding outfield catch.

"Playing here for a contender makes all the difference in the world to me in intensity," said flowing-haired, mustachioed Lowenstein who plays afield, and even bats, in prescription sunglasses that make him look like a Kojak heavy. "An alert player can use all his skills on a team like this. On a loser, they're lost."

Few Brewers, or fans among the 22,598 here today, are Oriole doubters now. The California Angels, whose 10-win streak was snapped today, are next on the agenda.

"Goin' to the big A in Anaheim," chortled Singleton, Ali-style. "Gonna see (Frank) Tanana and Mr. (Nolan) Ryan. They've won 10 in a row. We might just be ready for those guys."

Only four days ago, before Jim Palmer took the mound in Yankee Stadium and gave a sagging team a needed slap-in-the-face victory, the Orioles were ready for another of their April self-interments. Now, they seem transformed. "This felt like the real Opening Day," said GM Hank Peters.

A team that is already in heaven must now fly to the dangerous land of the Angels. CAPTION: Picture, A Bird in the hand is the best Sal Bando can do as he grabs John Lowentstein with the ball still in his glove during rundown.