Glide ratio for my RV-4
I've made some test of gliding my RV-4. You can download the result here...
https://dl.dropbox.com/u/3745995/WAF/gliding RV-4.kml
Open the file in Google Earth. Click on the track with right mouse button and choose "view elevation profile"...
You see three downhills. First is flown at idle and speed 85 kt, second at idle and 80 kt.
The third is at 80 kt with stopped engine by full leaning. Prop windmilling (fixed pitch metall, Sensenich 70CM759-0-81, IO320-160).
No flaps in any of the examples.
As you can see the third curve is steeper. That was what I have expected, but it's intresting to see how much.
You find the glide radio below. Not big difference between 80 and 85 kt at idle. But with the engine stoped it's a lot lower. That is something to think about if the engine really stop.
Glide ratio
Speed 85 kt, no flaps, engin at idle, prop vindmilling = 12,8:1
Speed 80 kt, no flaps, engin at idle, prop vindmilling = 13,3:1
Speed 80 kt, no flaps, engin stopped, prop vindmilling = 9,2:1
These values are specific to my aeroplane and my flight. Do not use them as anything other than an example. I take no responsibility for the declared values. You have to try out what applies to your own airplane.