"mikem" wrote:
You started the thread by acting surprised that not all aircraft
engines have oil coolers. I tried to point out that aircraft engines
have such large external surface areas, that if appropriately
cowled,
they can get rid of heat without an external oil cooler.

Where are you getting this from? I don't mean to sound insulting, but
this seems dubious. Appropriately cowled? All the light piston
aircraft I am familiar with are cowled the same: a forced air plenum
above the cylinders creates a differential pressure across the
cylinders and heat is conveyed out of the cowling by the resulting
airflow. In some installations, an oil cooler is installed to use this
same d. p. for additional cooling.

Adding an oil cooler has more to do with automatically regulating
engine oil temperature for water vapor boil off...

So in hot weather it's not needed?

...and constaining sizes
of cowling openings for streamlining (ala LoPriesti) than out of
pure
heat-transfer necessity.

On a Cessna 172?

The oil cooler removes heat from the engine and the medium that
conveys heat
to the cooler is oil. I don't see any difference between that and
how water
cools a water-cooled engine.

In those cases where a cooler has been designed in to acheive those
other criteria, niether do I, and I said so...

Well, you started out by saying that oil doesn't do cooling.
--
Dan
C172RG at BFM