97 Honda Civic knocking condition

I have a problem with a 1997 honda civil lx with what has been called a knocking condition by a mechanic. It sounds like a valve train knock, and is not a rod or bottom end knock. The car seems to be straining just to go slow speeds. My last engine died because it got dented and ran out of oil. So I had the engine replaced with one that was supposed to have only about 60k on it. Now I have exactly the same problem. It is very loud. It has caused my ears to ring.
It seems to be a little better when it is cold. It has trouble going up hills or mountain passes. Also I wondered if I can get a refund if this is due to the engine just being worn out and tired like they said the last one was. Thank you for any help on this.