For what it's worth, the Wright Brothers invented the first aircraft engine. It had no cooling at all in the usual sense -- just pistons embedded in a large block of aluminum (I think it was) that acted as a heat sink. They got away with this for the Wright Flyer because the engine was not intended to run for extended periods of time.
Message: The Wright Brothers were the first true aeronautical engineers. They didn't simply cobble together an aircraft that happened to fly. Their engine design was specifically intended to increase the horsepower-to-weight ratio by decreasing the weight.