=20 My cooling system now seems well (if not optimized) matched to my current in= stallation. Full power take offs on hot days see my cooling temps elevate t= o 200F for oil and 210-220F for coolant. Once I hit 120 MPH IAS the cooling= system catches up and starts to eliminate the cooling deficit. =20 =20 At my normal retired-man cruise of 7- 8 gph, my coolant and oil range from 1= 55-170F depending on OAT. When I push it to my max fuel flow/power 10.5-12.= 5 gph at altitude the temperatures of both increase until they are in the=20= 190-195F range. This gives me my maximum true airspeed. So it appears my c= ooling capacity is about right where I need it. Certainly a surplus at low= power cruise, but just adequate on take/off climbout on hot days and adequa= te for full boogie flight. =20 I really don't know how much drag (if any) I have eliminated, but I am convi= nced that it is less than if I had more of the core exposed to high velocity= airflow. =20 =20 Sorry, I can't be more definitive about it - I would like to know as well, b= ut only so much time to get all the wonderful projects on my list done. Per= haps someone with the inclination and time will someday put this idea in a w= ind tunnel and tell us {:>) =20 Ed =20 =20 =20 =20 ________________________________________________________________________ AOL now offers free email to everyone. Find out more about what's free from= AOL at AOL.com. ----------MB_8C95EF7A86E7C07_B30_1D50A_webmail-dd08.sysops.aol.com Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset="utf-8"

Ed= , It does really sound like you have a good handle on things. Truly for best= efficiency you want to run a bit hotter. Most of the cars now use 180=C2= =B0F thermostat and many 190=C2=B0! They are after mileage for the CAFE requ= irements though. Lynn has mentioned several times that the best power range=20= is around 170 for the rotary and that sounds about right. The interesting pa= rt is that as you inprove your cooling your max power changes, usually towar= ds more, thank goodness. I intend to have my radiators in a "cheek" position= so I can run a longer wedge duct to them. Time will tell if this is any bet= ter than the evap cores. At least on the rotary you don't have as much stuff= blocking the exit. We would all do well to consider that factor when design= ing our setups.

I would really like to thank you Ed for your efforts to help all=20= of us who come later to the party. Your chronicles of both the good and= the bad will save many people from peril, THANKS AGAIN. Fly safe and o= ften!

Bill Jepson

-----Original Message-----
From: eanderson@carolina.rr.com
To: flyrotary@lancaironline.net
Sent: Mon, 7 May 2007 11:19 AM
Subject: [FlyRotary] Re: Pinched Duct

Hi Bill,

<SNIP>

My cooling system now seems well (if not op= timized) matched to my current installation. Full power take offs= on hot days see my cooling temps elevate to 200F for oil and 210-220F for c= oolant. Once I hit 120 MPH IAS the cooling system catches up and start= s to eliminate the cooling deficit.

At my normal retired-man cruise of 7- 8 gph= , my coolant and oil range from 155-170F depending on OAT. When I push= it to my max fuel flow/power 10.5-12.5 gph at altitude the= temperatures of both increase until they are in the 190-195F range. T= his gives me my maximum true airspeed. So it appears my cooling capaci= ty is about right where I need it. Certainly a surplus at low po= wer cruise, but just adequate on take/off climbout on hot days and adequate=20= for full boogie flight.

I really don't know how much drag (if any)=20= I have eliminated, but I am convinced that it is less than if I had more of=20= the core exposed to high velocity airflow.

Sorry, I can't be more definitive about it=20= - I would like to know as well, but only so much time to get all the wonderf= ul projects on my list done. Perhaps someone with the inclination and=20= time will someday put this idea in a wind tunnel and tell us {:>)<= /div>

AOL now offers free email to everyone. Find out more about what's free from= AOL at AOL.com.

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