How does timing effect an engine to overheat or not?

If the timing is too high on an engine it causes the gas/air mixture to pre-ignite before the piston gets to top-dead-center. All the valves are closed at this time, causing an excessive amount of heat to be stored in the cylinder walls. And the same applies if the timing is too low, but it does it after the piston has passed top-dead-center, and the engine usually runs worse.