flyrotary@lancaironline.net Mailing List Archive

FWIW; I followed the rule of thumb of about 30% more cowl exit area than cooler (scoop) inlet area. I get ample air flow through the rad, in-cowl temps typically 140-150F, and a positive pressure in the cowl of about 5” h20 to accelerate the air going back out. Seemed to work out pretty well.

-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Tracy Crook
Sent: Wednesday, September 16, 2009 5:41 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Re RV-8 cooling test

Ah-h-h; had you considered the use of a water manometerJ?

It was not connected to an under cowl probe (my bad) but I had a better instrument than a water manometer (a custom version of the EM2 with a low air pressure readout) but there were other factors. Oil temps right at redline are distracting to me while trying to gather data. The under cowl temps were so high that the alternator was dropping the regulated voltage. The coil temps were close to the point where failure occurs. After landing, the temps went high enough that the coils started misfiring at anything over 2300 rpm. I wanted a test environment without so much stress.

Everything was so nice with the cowl off that I flew for about 45 minutes while the EM2 auto programmed the EC2 map table.

Tracy

On Wed, Sep 16, 2009 at 6:29 PM, Al Gietzen <ALVentures@cox.net> wrote:

Time is limited before I leave on vacation and I really needed to know the answer before I do. So, last night I made the decision to fly the -8 one more time - This time Without the cowl on. Secured anything that might get blown loose with tie wraps and did the deed. Whoo Hoo!