Originally Posted by
martymayes
The engine would have to be inspected to ensure it conforms with with type design and it has to be in condition for safe operation, including compliance with Part 39. If it has no records, will need the equivalent of an overhaul to determine conformity and condition for safe operation.
FWIW, there are no regs that require an "aircraft engine" to have an annual inspection, and a 100hr inspection is only required for certain type operations. If an engine is inspected and maintained under part 43, the inspections, maintenance and preventive maintenance has to be recorded in the logs and returned to service by an authorized person.