On Fri, 8 Aug 2003 19:19:30 -0500, "Dan Luke"
wrote:

"mikem" wrote:
Oil doesn't do "coolling" per se;

What I tried to convey is that the oil doesnt cool the engine; Oil is
used to reduce temperature gradients inside the engine. "Cooling"
takes place where the airflow comes in contact with metal...

When an "oil cooler" is added to an engine, it simply increases the
total surface area of the engine assembly that the cooling airflow can
interact with.

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.

Adding an oil cooler has more to do with automatically regulating
engine oil temperature for water vapor boil off and constaining sizes
of cowling openings for streamlining (ala LoPriesti) than out of pure
heat-transfer necessity.

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...

MikeM