flyrotary@lancaironline.net Mailing List Archive

Yep, the next step in the process (after verifying that there is good pressure in front of the rads) is to make sure the pressure is not too high behind the rads. Sounds like yours was. Mine is moderate (2 - 3" H2O depending on airspeed) with the stock RV-4 outlet which is about 2.5" X 18". My cooling improved by about 5 - 6 degrees when I rounded the sharp corner at the bottom of the firewall to reduce turbulence at the outlet. This also improved the velocity of the exit air which reduces drag.

Your temps are pretty good. My oil will go a little over 210 under the conditions you listed. A cowl flap would probably improve this but it is easy to keep it lower by backing off to around 23" MAP. ROC is still over 1000 fpm at that setting so it hasn't been an operational problem. At around 90 OAT I can use WOT in climb.

Tracy

----- Original Message -----

From: Bill Eslick

To: Rotary motors in aircraft

Sent: Tuesday, August 05, 2003 10:26 PM

Subject: [FlyRotary] Re: Cooling / Pressure recovery

NOW you come up with this! I already did it the hard way. Pressure recovery was good, and the biggest improvement came from opening up the cowl flap. I made a new one that is about twice the size of the original. Now I can climb out at 25 inches MAP with OAT over 100F, and the oil stays under 200, and the coolant stays about 205. Does that sound reasonable for temps?

Bill Eslick

-------Original Message-------

> There is quite a bit more but here is the key
part. Use an extra
> airspeedindicator to measure the pressure at
various places around
> the heat
> exchangers, especially the 'front' side.

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