Can we make a self cooling engine?

Question

i.e. Engine without a radiatior, etc.

Answer 1

Any engine that supports combustion will need cooling, otherwise it will continually heat up until it reaches its melting temperature.  We can certainly create engines that are cooled with just air, with enough surface area, we could build an engine that has enough surface to cool by natural radiation.  Depending on the application you can certainly minimize the required cooling medium, be it air/oil/water, but no cooling is impossible.    In a sense, all engines are self cooling, it is just a question of the cooling medium.

Answer 2

You mean like an air cooled VW bug 4 cylinder engine, or an air cooled motor cycle engine.

Answer 3

May be possible if you could find or create material that could take on the heat stress inside the engine while also being able to conduct the heat from the engine, without interfering with the efficiency of the engine cycle.

Look into new nanomaterials and resin fibers for possible candidates.