You need to Herp it a little more. So describe the noise besides "death" and "horrible" use better descriptors. Knocking, Clunking, Ticking are all acceptable. If the timing chain broke or skipped a tooth the engine would not run......at all. Maybe the tensioner for the timing chain is going out. But why did you tear the top end off when the sound was coming from the bottom? It's a little late but invest in a mechanics stethoscope it will help you pinpoint problems in the future.
Jeff