Francis J. McNamara Sr., 82, deputy alien property custodian here during and after World War II and a retired officer of the Remington Rand Division of the Sperry Rand Corp., died Friday of congestive heart failure at his home in New Canaan, Conn.

Mr. McNamara became assistant to the alien property custodian in 1942 and was named deputy two years later. Earlier, he had been chief attorney in the Alien Property Bureau and special assistant to the attorney general, when the bureau was part of the Justice Department.

As deputy chief in the Office of Alien Property Custodian, Mr. McNamara had to dispose of $300 million in alien property, including estates, trusts, corporations, contracts, cartels, patents and personal property, such as jewelry confiscated by this country during World War II.

After leaving the government, he joined Remington Rand Inc., which merged with the Sperry Corp. in 1956. He was vice president and general counsel of Sperry's Remington Rand Division when he retired in 1961.

Mr. McNamara was born in Watertown, Mass. He graduated from Boston College and earned a law degree from Boston University Law School.

He served in the Army during World War I.

Survivors include his wife, the former Louise English, of the home; a son, Francis J. Jr., of Darien, Conn.; two daughters, Mr. Peter Driscoll of Redding, Conn., and Mrs. Herman J. Eckrich of Darien, and 20 grandchildren.

The family suggests that expressions of sympathy be in the form of contributions to the New Canaan (Conn.) Visiting Nurse Association or to the Waveny Care Center Inc., in New Canaan.