"Porky's" takes lip-smacking aim on the teen-age raunch market. Set among prankish high school boys in Florida, circa 1954, it's a sniggery exercise in juvenile sex farce.

Some of the lewd goofiness is surefire; it's almost impossible to resist certain caught-with-their-pants-down sight gags. However, the cumulative effect of the antics in "Porky's" is more debilitating than amusing.

The bare-bottomed slapstick doesn't lack energy, but it is conspicuously short on wit. The whole overcalculated apparatus could be bowdlerized for the coyly smutty requirements of a TV sitcom without losing anything.

Moreover, there's an ultimately vicious streak in the material that leaves a distasteful aftertaste. "Porky's" is too crass to incorporate a hint of romantic attachment, with the possible and surely unintentional exception of a blossoming friendship between two boys who start out as antagonists.

This oversight should place "Porky's" at a considerable disadvantage compared to the better movies it inevitably recalls, especially "American Graffiti" and "National Lampoon's Animal House." An evening at "Porky's," which opens today at area theaters, may also enhance your respect for the excessively low-key approach of "Diner."

Essentially a stag comedy for adolescent boys, "Porky's" limits the range of female characters to happy high school nymphos (Kaki Hunter represents the coeds and Kim Cattrall the faculty), salty hookers (Susan Clark) and one fanatic prude, the obese character actress Nancy Parsons as a fuming gym teacher named (haw-haw) Balbricker.

This selection would appear to offer scant gratification to the female segment of the audience, which is evidently supposed to feel grateful for the chance to eavesdrop on vintage misinformation about the single-minded pursuit of young boys.

The title refers to a honky-tonk strip joint located over a mangrove swamp in a neighboring, roughneck county. The boys from upper middle-class Angel Beach (writer-director Bob Clark grew up--to a point--in Fort Lauderdale during the '50s) crash notorious Porky's, presuming they can purchase the services of a stripper or two.

The proprietor, Porky, superbly embodied by a gruff, gross hulk named Chuck Mitchell, takes their dough and boots them out.

It's not as if our obnoxious young heroes deserved much consideration from the world of vice. Nevertheless, their setback at Porky's is used as the pretext for a vendetta which culminates in an elaborate finale of demolition. Although calculated to send the audience out in a jolly mood, this commando caper comes closer to destroying credulity and inspiring sympathy for the supposed villain.

Given the prevailing tone, it seems both inappropriate and underhanded when Bob Clark attempts to work in social sidelights like corruption and racial prejudice. While you don't doubt that they belonged to the setting and period, they're doomed to look freakish and arbitrary in the vulgar context of "Porky's."

Scott Colomby, cast as the rich, self-possessed Jewish kid who proves handy with his dukes, probably has the closest thing to an appealing role, loaded as it is with excess virtue and echoes from Montgomery Clift in "From Here to Eternity" and "The Young Lions." Although there's little to differentiate their characters from the surrounding gang, Wyatt Knight and Tony Ganios (who made a likable earlier impression as the big, studly kid in "The Wanderers") demonstrate an easygoing rapport with the camera.

Clark shows no inclination to be subtle, but his worst mistake is belaboring situations on the mistaken assumption that they'll become infectiously hilarious. There are two jawbreaking examples of this tendency. A coach played by Doug McGrath is sent into prolonged sniggers to encourage the audience to yuck it up during Kim Cattrall's scene of orgasmic caterwauling. In a similar respect, a quartet of actors is obliged to surrender to chortling fits during a lengthy sequence designed to heap ridicule on the prudish Balbricker.

Although it tends to single out fat, slobby characters for abuse, the trouble with "Porky's" is that it's dependent on a gross, slobby sense of humor.