OO Civic ex sohc V-tec 1.6 135,000mi burning alot of oil after a valve job. A real valve job, not a bubblegum & tooth paste job. Exaust valves, 5 guides, all seals. This started out as a dead cyl. (#3). Two very burnt exaust valves & now a melted converter & oil burning. any thoughts?

 

possible valve seal seated incorrectly during install

 

Or your nice new sealing valves blew our your old tired bottom end. This is why you typically want to avoid doing only a super duper valve job on an old engine. Not saying that's your case, but that's the general rule I've always heard and have followed.