If an engine is using huge amounts of oil, and recently rebuilt, something went amiss in the process.
It is normal to use a little oil till the rings seal, but not huge amounts.
Did you bore it or have it done?
Is this your first attempt or are you experienced at engine rebuilding?
Did you put the piston rings in the bore individually, and check the end clearance before installing them on the piston, and assembling?
Was the bore washed thoroughly with hot soapy water before any assy. was done?
It sounds like it got hot during break-in and you sized the piston, causing ring/piston/cyl. damage.
But we need a lot more info before advising investigative tare down,
as this may well
not be the case.
