I’m a licensed A&P and I approve of this msg. Release temperature increases (exhaust temp) from unburnt fuel (afterburne) in a rich mix or slow engine (retarded timing). Both can be used to lower engine operating temperature.Advancing ignition timing increases engine temperatures. As you increase towards MBT you get more power but temperatures may get so high that you melt a through the combustion temperature + compression increasing temperatures. You may also end up causing knock as the heat causes the flamefront to start forming away from the spark which causes pressure spikes that can shock load components to failure.
Pre-ignition is when the engine "diesels" and excessively high temperatures can lead to this. No amount of spark timing adjustment can prevent this, just AFR.
EGTs actually rise as you retard ignition timing as less fuel is burned before exhaust begins. Low (rich) AFRs will also cause high EGTs as the fuel hits the catalytic converter or fresh air and burns on contact.
Over-advancing your timing past MBT is never a good thing. You lose power and if you don't have knock every degree of advance will bring you closer to the knock threshold.
As a general rule if you are not knock-limited, you should advance timing to MBT and then back off until you lose ~3-5% torque. It will be just at the edge of perceptible loss and reduces the chances that you over-advance or start knocking in hot conditions.
I'm just a casual tuner though. Someone with real experience will probably chime in and prove me wrong.
Inversely, advancing timing to the correct amount will increase engine operating temperature while decreasing exhaust gas temperature. It varies by how much the temps will change because timing isn’t the only factor in engine temperature at that point.
So what can we discern from all this relevant information so that it becomes useful in your circumstance? If she’s too hot either increase the fuel to air ration (run it rich- recommended). Better to have and not need if you want to go fast- cool, or change the thermostat to one that opens at lower operating temperatures. Lol- I didn’t even look at how old this was before I posted but hopefully this helps someone.