Greek hippos < ek^wos... or not?

From: Joao S. Lopes
Message: 70976
Date: 2013-02-24

Is it sure to consider Greek hippos < *ek^wos, despite its clear irregular shift? Would we expect *epos, instead of hippos? Does hippos come from another IE language, or has it no relation to PIE root. Coincidence or not, the builder of Trojan Horse was called Epeios, is it a clue for an obsolete *epos in older Greek?

JS Lopes