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Posted for "Stu Seffern" <sseffern@Chorus.net>:

Our 360 oil temps in hot weather or steep climbs are borderline high even with the 9 vane cooler and a large NACA scoop.  We have suspected that the scoop location on the lower left cowl is in a low pressure area and the flow may be reversed.  This may actually help reduce the induced drag though. We can control it down for cold operation with a push/pull slide air valve.

Maybe we should just turn around the NACA scoop?  It would be nice to have better flow over the oil cooler when needed.

Has anyone found the best location for the oil cooler air inlet on the 360?

Stu.


[Stu, the shape of the ramp from your NACA duct to the oil cooler is very important... ask Jim
Frantz about the battle he fought with his before finding what worked.  A smooth transition
from the duct to the oil cooler without any angular turns seems to do the trick for most
people.  A properly shaped diffuser also helps, as well as adequate flow for the escaping air
as it exits the cooler.  Dick Alden had a small article and a couple pics of his oil cooler
setup in Issue #51 of the Lancair Network News.  Take a look at page 674 and let us know if
your setup is similar.  Dick's is on the pax side, and so is probably a bit more effective...
the left side seems to have some flow problems, but I don't think they're insurmountable.
Have you tufted the cowl and had someone fly chase with a camera to record what was actually
going on?  That's been a pretty common theme as well.

    <Marv>             ]

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