Charles Freeman Perry Sr., 51, a project manager at the Naval Ships Engineering Center until his retirement earlier this year for reasons of health, died of cancer Sunday at George Washington University Hospital.

Mr. Perry began his career with the Navy Department as a mechanical engineer. At the time of his retirement, he was assigned to a project to build a new rotary combustion engine for the Marine Corps.

He was born and grew up in Norwich, Conn. He served in the old Army Air Corps from 1945 to 1948 and then attended the old Mitchell Junior College in New London, Conn., and North Carolina Agricultural and Technical State University in Greensboro, N.C., from which he graduated with a degree in mechanical engineering in 1952.

He moved to Washington and began his career with the Navy Department the same year he graduated from North Carolina A & T. He subsequently took graduate courses at Catholic University and the Massachusetts Institute of Technology. He took a year's leave from the government to teach mechanical engineering at North Carolina A & T.

Mr. Perry was a member of the American Society of Naval Engineers, the American Society of Mechanical Engineers and the American Society of Engineers at the Naval Sea Systems Command.

He had been active in the Boy Scouts and had served as Cub Master of several groups in Washington. He also had been active in Neighbors Inc., a community organization. He was an amateur photographer and model ship builder.

Survivors include his wife, G. of the home in Washington, a daughter, Karen, of Arlington, a son, Charles F. Jr., of Hyattsville, a sister, Maria Simmons, of Uncasville, Conn., and a nephew, Marvin Perry, who grew up with him, of Washington.