X-Mozilla-Keys:                                                                                 
Fred wrote:

The best oil coolers are a lot like those made by Stewart Warner and used on
Lycoming and Continental engines.  They are optimized for small size and
light weight rather than low drag, but fin spacing and such are near optimal
for low drag if you get such an oil cooler but get it a bit oversize to
reduce the air flow velocity required per square foot of fin frontal area.
(Bigger frontal area and thinner core means lower drag.  Bigger frontal area
with same thickness and same air flow is also lower drag because it requires
lower air velocity through the oil cooler.)  If you don't see fins spaced
16-22 fins per inch and interrupted to keep cutting the flow, you are not
looking at a high performance design, and can do better.

Fred

Ed please count the fins per inch on that Earl's oil cooler you took off
your
airplane for us. I am kind of curious how well it meets Fred's
criteria.

Paul Lamar
 
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