When the Saxonia landed in New York on April 14, 1914 it included Fotis Voyatzis 18. He was born in Vourca, Greece and headed to Freeport, IL. The passage was paid for by his father Itamkis of Vourca. Hopefully this is your great-grandfather.
The lack of more data such as when and where he died. where he lived, who his was married to, his children's names, etc make it harder to find more data on him. Posting as much as you can makes it EASIER.
He may have changed his name to make it sound more "American".