How long was it ran without oil? How did it ran out of oil? Did it set unused for a long period of time after the oil issue? It's terrible either way but if it was just a brief minute or two it might be serviceable. If it was ran until it soft seized then you could be assured some damage was done or a catastrophic amount was done. Have you attempted a compression test? Try draining the oil and see what contaminants or debis is in the oil you briefly ran it on. Was it knocking or tapping when it ran? I would do a compression test and if that shows serviceable compression then I would get a borescope to check the cylinder walls and piston. It's very possible that the engine was heavily damaged but there's no sense in throwing it out without at least checking it. I assume from what you've said that you don't have the tools to diagnose these issues. Harbor Freight has a compression test kit for $30 and you can get a cheap borescope that connects to an android phone from Amazon. Last thing, where are you located? Someone near you may be willing to check it for you.
