INDIANAPOLIS, AUG. 21 -- The members of the Cuban and U.S. boxing teams have found a language in common at the Pan American Games, that of intimidation.

A Cuban makes an insulting gesture, an American turns his thumb down. They knock against each other in hallways, make noises like ambulance sirens and generally go out of their way to make it known they cheerfully dislike each other.

"There is one thing in the back of every American boxer's mind, and that is stopping the Cuban," said light middleweight Frank Liles, who lost to his opponent, Orestes Solano, in the semifinals Thursday night. "It's always fighting the Cuban. And winning."

This is nothing new, of course; it is part of the storied rivalry between the two dominant amateur teams in the world, who will fight three gold medal bouts against each other in finals Saturday and Sunday. On Saturday, bantamweight Michael Collins meets Manuel Martinez, and world champion welterweight Kenneth Gould faces knockout specialist Juan Lemus. On Sunday, light welterweight Todd Foster meets Candelario Duvergel.

Two more Americans will fight for golds when light flyweight Michael Carbajal meets Luis Rolon of Puerto Rico Saturday, and featherweight world champion Kelcie Banks meets Emilio Villegas of the Dominican Republic Sunday. But the Cuban bouts certainly will take precedence in light of recent tensions at the Pan Am Games, and of the United States' efforts to make up some ground lost to Cuba in earlier rounds.

The United States has a 2-7 record against Cubans so far. The five Americans going for gold medals is two short of the number coach Roosevelt Sanders had hoped for and five fewer than Cuba advanced. Also, tensions have been running high since a group of Cuban boxers went into the stands and brawled with anti-Castro protesters last week.

"The Cubans try to intimidate us," said Banks, who eliminated Cuba's Arnaldo Mesa in the quarterfinals. "They use the hand signals, making little signs, pushing past you in the hallway. I don't think we could ever sit down at a table together."

According to Angel Espinosa, who scored a devastating knockout of middleweight Darin Allen in the first round of their quarterfinal, the Americans use the same tactics.

"Quite the contrary, the U.S. boxers do it to us," he said through an interpreter. "They go in front of us very prideful, acting like the best. When deep inside they know we're the best."

Collins' bout against Manuel Martinez is something of a mystery. The little that is known of the Cuban is that he is 20, a six-year veteran who won the 1987 Cordova Toneo tournament. According to Collins, he already beat a more difficult opponent in the semifinals, with a unanimous, but difficult, decision over Puerto Rico's Rafael DelValle.

Collins, 23, is a compact, intelligent boxer who has won three national championships, and was a silver medalist at the 1982 world championships. He never has fought Martinez, but he has a 2-1 record against Cubans, and decisioned Yuri Alexandrov earlier this year in a dual meet with the Soviets. He just missed being a member of the 1984 Olympic team, losing a 3-2 split decison to Steve McCrory, instead watching on TV from Texas, where he works in a tire store.

"I'm not worried about the Cuban because the Cuban doesn't really impress me," Collins said.

Foster, 19, from Great Falls, Mont., will have perhaps the most difficult fight of the U.S.-Cuba matchups. Duvergel is a smooth boxer and has been called the class of the Cuban team by Sanders.

At 6 feet 2, Duvergel will have a reach advantage over the 5-7 Foster, and also an edge in international experience. Duvergel is defending Pan Am champion at 139 pounds, but made it to the finals at 147 pounds in the world championships before losing to welterweight Gould.

Foster is more than just an unknown, he is an utter secret. He only made the U.S. team by winning the Olympic Festival, and then upsetting national champion Nick Kakouris in the Pan American box-off. But he has shown himself to be a smart, efficient boxer who got to the finals with a knockout and two unanimous decisions.

"He did it on determination," Sanders said. "He's got desire, and he's got momentum."

Gould, 20, from Rockford, Ill., is one of three U.S. champions (along with Banks and Allen), but is considered an underdog, having lost twice to Lemus, once by knockout. Lemus, 19, has not had a fight go the distance here, referees stopping all three of his bouts as he has practiced the typical Cuban punch, a devastating, bolo-style right uppercut.

"I expected to meet more of a challenge here, but so far I haven't met anyone to give it to me," he said with a shrug.

Banks and Carbajal already have eliminated Cubans, and so are considered good bets for the gold. But Banks has not fought particularly well, suffering a knockdown before decisioning Cuba's Arnaldo Mesa, and a good aggressive fighter might beat him.

Carbajal, like Foster, is here by virtue of victories in the Olympic Festival and Pan Am box-off. Thus, he may be at a disadvantage against Rolon, a tough Puerto Rican champion who took a silver medal at the 1986 world championships. But Carbajal has the impetus of a startling unanimous decision over Cuban world champion Juan Torres in the semifinals.

The U.S. still has a chance to better the 1983's performances in Caracas, where Americans won just two gold medals to seven for Cuba. That Cuba has a chance at 10 gold medals is not a surprise, at least to them.

"I am not surprised," Cuban coach Alcides Sagarra said. "We work our boxers to prepare for this. What they are doing is winning."