Here's what is planned for the 6.2-acre Alexandria Torpedo Factory complex by 1986:

* The Art Center, a gray, block-long factory building distinguished by a massive arched entrance and expansive windows and skylight will open May 21. The center will house 86 art studios, the Art League School and galleries along with the city's archaelogy program. Amid its exposed pipes and painted ductwork, vistors will stroll the center's 71,318 square feet watching artists paint, print, stain glass, and sculpt in ceramics, metal, stone and wood.

* A renovated five-story office building, located directly across Cameron Street from the remodeled art center, is scheduled to open in June. The building is being restyled with an Art Deco facade of brick, colored tiles and bronze-tinted windows.

* A 463-space garage is scheduled to open along with the office building. An underground 80-space parking garage is to open next summer.

* A 114-townhouse development surrounding a courtyard is planned for the area above the parking garage. It is scheduled to open in the spring of 1985.

* Tentative plans also include the renovation of the building sharing the southern wall of the art center to be used for retail and office space, a marina for pleasure boats and a restuarant overlooking the Potomac.