In April 1941, as the German invasion of Greece had almost overrun the country, as much of the Greek fleet as could be saved was sent to the Allied-held Middle East.

Although only a subaltern, Engolfopoulos took over command of Nirefs and led his vessel to the Middle East, where he joined the forces of the Greek government-in-exile.

Promoted to captain on 8 January 1954, he served as director of the Hellenic Navy General Staff's A1 Bureau and underwent training at the Naval War School (1954–55), then served as captain of the Greek flagship, the cruiser Elli, as well as chief of staff to the Fleet Command (1955–56), and commanded the Kanellopoulos naval training centre (1956–58).

[1] Returning to Greece, he was appointed Chief of the Navy General Staff's Second Section (Organization) and was promoted to rear admiral on 23 April 1964 (retroactive to 8 February).

[1] Due to his known opposition to the regime, he was offered the leadership of the long-planned mutiny by the mostly anti-junta oriented navy, but he refused, as he did not believe it stood any chance of success.

Indeed, the conspiracy was betrayed and the uprising in May 1973 failed; only the destroyer Velos managed to escape and its officers, led by captain Nikolaos Pappas, sought political asylum in Italy.

[1] Following the collapse of the junta and the restoration of democracy in July/August 1974, he served as Minister for Mercantile Marine in the national unity government of Konstantinos Karamanlis from 6 October to 21 November 1974.