X-Mozilla-Keys:                                                                                 
Mike Wills wrote:

At 04:36 PM 8/12/1999 -0700, you wrote:

RJohn15183@aol.com wrote:

In a message dated 8/12/99 5:32:06 PM Central Daylight Time,
rotaryeng@earthlink.net writes:

I think I have finally figured out how to get enough radiator
 area useing only one rad to cool 250 HP or so.

The intercooler is a nice setup but IMHO I don't think the coolant radiator
will work Paul. The intake is to close to the prop. All the successful WWII
liquid cooled planes had one thing in common. Rad intakes set way back from
the prop to get "clean" airflow.

 Contrast this with the small round inlets found on Lancairs, and some of
the faster RVs with custom cowls. These inlets are placed pretty close to
the prop and in spite of being pretty small provide good cooling. The air
doesnt know its going through fins on a air cooled engine rather than
through a rad core. It appears that the key difference between these
airplanes and the examples you mention is a good inlet diffuser that
converts the velocity to pressure.

 I plan to use a chin type inlet such as Paul shows. I dont necessarily
agree with his theory on a large thin radiator stretched out 90 degrees to
the airflow versus a thicker rad perpendicular to the airflow. I'd like to
see some comparison testing on this but like everyone else I dont have the
time nor resources to test it myself.

Mike Wills

We have a few examples of the large and thin flying. Jim Mosure for one.
Dave Atkins, Ted Mayfield, Chuck Harbert, all new cars :-).

According to Kuchmann and Weber the high angle duct works quite
well as a diffuser. I am seeing more and more examples of
flat rads. Tom Jordan should soon fly his supercharged airplane
with a P51 style duct and a flat rad under the engine.
Good sealing around the rad is critical.

Paul Lamar
 
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