More of a 'th' than a 'z' I would have thought. (BTW I read today that 'th' is disappearing from English English.)

I see that modern Greeks seem to call him 'Eethipothos' or something like that: Οιδίποδας But maybe I misunderstand that page - it's 50 years since I studied ancient Greek!

How the ancients pronounced it, who knows? How do we know that a Latin V is pronounced W?