Why huge block engines don’t need active cooling?

[Dashz]

I saw that some engines, like the rcmax 80cc for the ramminator, don't have flywheels (or at least turbines)
Why is this?

 

[Z.hb71]

I saw that some engines, like the rcmax 80cc for the ramminator, don't have flywheels (or at least turbines)
Why is this?

If you let them idle long enough then they will overheat but nobody does that. When they are moving they have plenty of cooling over the fins . The rcmax 88 does have a Normal flywheel but generally they don't really need it