system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: I don't understand how it is possible to cool a car engine with air alone. So how does air-cooled engines work?
gpt
There is a lot of air, and the average temperature of the air is suitable for long-term engine operation.  It's simply a matter of exchanging the engine heat with enough air.  Even liquid cooled engines do this, they use a fluid to move the heat to a radiator and from there into the air.  An air cooled engine simply does it directly.  It uses fans to circulate a lot of air over an engine structure with fins to provide enough surface area to exchange the heat.