Horrible Ignition noise when warmed engine

Diagnosis on a problem like this needs to be done in a certain order, or, you're just guessing the problem. First thing you need to determine is whether the battery it good or not. The only good way to test it is with a load tester before and after it's been charged. Once you are sure the battery is good (and connections are clean), test to see that the charging system is working properly. If you're still getting a low voltage chatter in the start position, the rest of the battery cable connections need to be checked. That means the other end of the actual battery cables, and the heavy cables going to the starter motor from the starter relay. Make sure the cables are connected to where they're supposed to be connected. The negative battery cable should bolt to the cylinder head or block and with paint cutter bolts/washers. I'd also make sure there is a good ground strap going from the engine to the body and from the negative cable to the body also. With your car cranking fine cold, but, not cranking when the engine is hot, indicates to me that the starter is drawing a lot more juice than the system can handle after the starter warms up. A fairly common problem with headers or an exhaust pipe close to the starter. Sometimes adding a heat shield or wrap will help. It still shouldn't chatter though. Under high heat-no start conditions, usually the starter will just drag and crank real slow. The chatter indicates low voltage or bad connection. You can sometimes check battery cables and the heavy relay to starter wires with jumper cables. The negative cable is easy to check. Just add a jumper cable from battery negative terminal to a clean metal connection on the engine and try to start it now. The battery to relay cable is also not to hard to test in most cars. Test the same way.....jumper cable from battery positive post to the battery post on the relay and try to start. The relay to starter motor cable is a lot harder to jump on a V8 car. Care must be taken not to accidentally ground the jumper cable or cross the wire connections on the starter. Sometime you have to make a jumper cable with better connectors on the starter end.