Fireball 500 (1966)

Not exactly a "beach party" movie, but it's included in the mix because of the appearance of Frankie Avalon and Annette Funicello.  The plot revolves around the world of stock car racing.  Dave (Avalon) shows up in a southern town to challenge Leander (played by Fabian), the local car racing hero.  Leander's girl is Jane (Funicello), who tolerates Leander's female fan club who constantly hang around him. Her uncle Big Jaw (Chill Willis) runs the carnival where Jane works, and he has an interest in the car racing. Martha (Julie Parrish), the town's rich widow takes interest in Dave.  She gets Dave hooked up in running moonshine, which Leander does on the side as does a racing promoter named Charlie Bigg (Harvey Lembeck).  Dave doesn't want any part of it.

However, agents from the IRS, who have been trying to shut down the moonshine operation for awhile, force Dave to act as an informant.  When another moonshine runner is killed on the road, Dave suspects that Leander is to blame.

There's nothing particularly special about this movie, which is just another in a long line of B (and C grade) movies about fast cars and their drivers.  Avalon and Funicello get to sing a few numbers, which don't exactly fit in a movie that is supposed to be a drama.  Fabian, who is also a singer, doesn't sing at all in this one.  In fact, it appeared that this movie was designed to change the teen idol image of the main actors.  Avalon drops a curse word in one line, is shown drinking alcohol, and another scene hints that Avalon has slept with Parrish's character.  But Fabian doesn't do more than swagger and sneer, and Funicello's character is another version of the good, level-headed girls she always played.