"No hot water!" Earl Weaver yelled from the icy recesses of his shower. "We win 13-5 on opening day and we can't even get hot water?"

Those on-the-fritz locker room showers this afternoon may be as close as anybody comes to pouring cold water on the Baltimore Orioles this season. In baseball, there's no magic like home-run magic. And, it now appears, the Orioles' long-ball legerdemain is finally back.

All last season, Weaver moaned and grumped about the absence of his friend, Dr. Longball. Each week, the manager would count up how many homers his club was behind its pace of 1979 and '80 when the Birds--over two seasons--had led the majors in home runs. Without punch, Weaver knew, all his club's precise pitching and its savvy fundamentals just weren't enough.

But the good doc never arrived.

Finally, the Orioles admitted that they had to do major power surgery.

Now, Weaver and his Birds believe, the crash is back in their attack. Not just for one gloriously bright, crisp April day, but for a whole season.

From the moment rookie Cal Ripken Jr., in his first at bat of the season, launched a soaring fly into the Orioles' bullpen, this was a day for uncorking the bottle of that mysterious team chemistry.

"I wanted to jump up in the air," said Ripken, grinning. "Getting my first (major league) homer on opening day has always been one of my little dreams, ever since I hit a homer on opening day in AA (in 1980), then did it again last year in AAA. The feeling was all it was made out to be when I was thinking about it.

"I was a little disappointed in my dad (third base coach Cal Sr.)," said Ripken, deadpan in expression. "I thought he'd jump up and hug me, or give me a new handshake . . . I'm just kiddin'. I knew he wouldn't do anything special for me."

One act of barbarity against Kansas City pitching simply begot another.

Just as the clock struck 3, Eddie Murray tolled four, going deep with the bases loaded off ace starter Dennis Leonard, the man who has more victories since 1976 than any other right-hander in baseball.

As though that jumping, high-fiving celebration weren't enough, Gary Roenicke, just two batters later, conked a homer into the Bird pen only two pitches after missing a homer by a yard with an upper-deck blast above foul pole level.

"I've never felt so comfortable at the plate or been quite so hot for so long," said Roenicke, who was four for five and now has reached base 35 times in his last 63 plate appearances.

"It's been a long two years," added Roenicke, whose 25 homers were a key in '79, but who, because of injuries, lost confidence and tinkering with his stance, has been mostly invisible for two seasons.

As a closing act, Dan Ford finished the scoring with a three-run homer into the left-field bleachers. When he got to the dugout, Roenicke was waiting.

"Before the game, Dan said maybe we better invent a new shake, in case either of us hit a home run. So, we made up the 'hi-low five.' "

This, as the world is no doubt breathless to hear, involves a conventional high-five, followed by a 360-degree spin and a behind-the-back, below-the-waist slapping of the left palms. Let it be noted that, typical of this pluperfect Oriole day, Ford and Roenicke pulled it off smoothly.

What the Birds now know they have is exactly the devastating kind of lineup core they had in '79: a quintet of back-to-back sluggers, each of whom can hit more than 20 homers.

In '79, the wallop went thus: Singleton, 35 homers; Roenicke and John Lowenstein (platooned in left), 36 homers in 573 at bats; Pat Kelly and Lee May (platooned at DH), 30 in 609 at bats; Murray, 25, and Doug DeCinces, 16.

Now, with Ford, Ripken and the apparently reborn Roenicke joining Singleton and Murray, the Orioles have a lineup that the exuberant pitching coach, Ray Miller, said "looked like the greatest promotional event the Orioles could have ever put on out there today. Hitting like that will sure as hell build attendance and you don't have to give nothing away."

The Orioles played so ridiculously well that Weaver threatened not to retire, saying, "If we hit four homers every game, maybe I'll come back next year."

When it wasn't shortstop Lenn Sakata starting a double play, it was relief winner Sammy Stewart giving more fuel to the Bird contingent that believes it's time to "Free Sammy Stewart Now."

Even "switch hitter" Rick Dempsey, who probably has the most awful-looking left-handed swing in the history of the sport, got a shattered-bat single from that side of the plate. His mates, who hope he grasps what a joke his hack looks like without their having to tell him, presented Dempsey with the broken bat. Complete with the ball taped to the handle.

Commissioner Bowie Kuhn was lucky today, too. Nobody spotted him sitting in the mezzanine owner's box. Thus, nobody booed him. Kuhn, who never wears a hat, helped remain incognito with a brim-turned-down brown chapeau that looked like a perfect match for the jacket they give you in a restaurant when you've forgotten yours.

In the end, however, the best of good fortune was saved for nervous rookie Ripken, new Oriole Ford and rescued-from-the-doghouse Roenicke.

"It's like my (hot) starts in AA and AAA when I came back a second time," said Ripken, who hit .128 with the Orioles late in '81. "New town, new people, new level. You want to prove you're worthy of what people have said about you."

Owner Ed Williams grabbed Ford and said, "It's cold, but it beats California, doesn't it."

"Sure, does. Lots of ways," replied Ford, who also made two strong throws to the plate to prevent runs.

"After the trying things I've been through, brawls, contracts, Playgirl, I know the players are curious about 'just what kind of guy is he?' Earl Weaver's let Dan be Dan and that's helped. He lets you be loose . . . I wanted to make a good first impression on the fans. But this," Ford said, raising his eyebrows. "To top it all off with a cheer and the ding-dong (home run), well, I just hope I give my little fans out in the bleachers a reason to love Dan Ford in '82."

Now that the power's back, lots of Orioles may be giving their Memorial Stadium fans reason to fall in love again.