Brantel
Well Known Member
Here is a data point for those looking for independent data on how effective the ASA EZ Cool Cowl Flaps are.
My airplane is an RV7 with Hartzell BA CS prop and a 180hp carbed Lycoming.
I have installed 2 ASA EZ Cool Cowl Flaps in the lower cowl, one on each side as far aft as possible.
This test was done back to back with similar atmospheric conditions. I only had time for one IAS test and I settled on doing this test at 120kts IAS. I used the AP in IAS hold mode for both test.
Here was the test card:
1. Take off and fly around for at least 15 minutes just boring holes in the sky to get everything up to normal operating temp.
2. Within 3 miles of the airport at pattern altitude fly at 23/23 squared and enter the pattern and land.
3. Taxi back to the active runway and take off with the cowl flaps closed.
4. Activate AP in IAS hold mode with 120kts IAS selected and climb with everything full forward from field elevation 1350ft to 8500ft MSL.
5. Descend and fly around till the temps stabilize and within 3 miles of the airport at pattern altitude fly at 23/23 squared and enter the pattern and land.
6. Taxi back to the active runway and take off with the cowl flaps open.
7. Activate AP in IAS hold mode with 120kts IAS selected and climb with everything full forward from field elevation 1350ft to 8500ft MSL.
8. End test
Here are the screen shots of the logs as pulled from the G3X Touch:
The first two charts show the difference in the CHT (I only show the hottest one to make it easy to read). I see a Delta of 8°F not counting any minor OAT differences. Two things stand out to me. First is how much less time during the climb that the CHT stays near 400° and second how much lower the CHT is at the top of the climb with the flaps open.
Click for larger image...
![](/proxy.php?image=http%3A%2F%2Fi61.tinypic.com%2F2exoxp1.jpg&hash=3a4aa96bc778e90bd8c00093ab741471)
![](/proxy.php?image=http%3A%2F%2Fi58.tinypic.com%2F2q0r9sx.jpg&hash=04af59692695ce76f09ef187f5396abf)
The second two charts show the difference in the oil temp. I see a delta of 9°F not county any minor OAT differences. Again two things stand out. First is how flat the oil temp is during the climb and how much lower the oil temp is at the top of the climb with the flaps open.
Click for larger image...
![](/proxy.php?image=http%3A%2F%2Fi62.tinypic.com%2Fiyz8ub.jpg&hash=84312d72cdde054a88221d5cfb6608da)
![](/proxy.php?image=http%3A%2F%2Fi61.tinypic.com%2Fnvthfc.jpg&hash=0e09c73e843d2670451a95ce01f6aae0)
This last graph just shows the IAS from take off all the way to 8500ft MSL.
Click for larger image...
![](/proxy.php?image=http%3A%2F%2Fi62.tinypic.com%2F20paur7.jpg&hash=d3e7bb15698c9ad011d871d69385720d)
So far so good. I expect even better numbers if climbing at something less than 120kts IAS. Hopefully soon I can repeat the test at a slower climb speed.
My airplane is an RV7 with Hartzell BA CS prop and a 180hp carbed Lycoming.
I have installed 2 ASA EZ Cool Cowl Flaps in the lower cowl, one on each side as far aft as possible.
This test was done back to back with similar atmospheric conditions. I only had time for one IAS test and I settled on doing this test at 120kts IAS. I used the AP in IAS hold mode for both test.
Here was the test card:
1. Take off and fly around for at least 15 minutes just boring holes in the sky to get everything up to normal operating temp.
2. Within 3 miles of the airport at pattern altitude fly at 23/23 squared and enter the pattern and land.
3. Taxi back to the active runway and take off with the cowl flaps closed.
4. Activate AP in IAS hold mode with 120kts IAS selected and climb with everything full forward from field elevation 1350ft to 8500ft MSL.
5. Descend and fly around till the temps stabilize and within 3 miles of the airport at pattern altitude fly at 23/23 squared and enter the pattern and land.
6. Taxi back to the active runway and take off with the cowl flaps open.
7. Activate AP in IAS hold mode with 120kts IAS selected and climb with everything full forward from field elevation 1350ft to 8500ft MSL.
8. End test
Here are the screen shots of the logs as pulled from the G3X Touch:
The first two charts show the difference in the CHT (I only show the hottest one to make it easy to read). I see a Delta of 8°F not counting any minor OAT differences. Two things stand out to me. First is how much less time during the climb that the CHT stays near 400° and second how much lower the CHT is at the top of the climb with the flaps open.
Click for larger image...
![](/proxy.php?image=http%3A%2F%2Fi61.tinypic.com%2F2exoxp1.jpg&hash=3a4aa96bc778e90bd8c00093ab741471)
![](/proxy.php?image=http%3A%2F%2Fi58.tinypic.com%2F2q0r9sx.jpg&hash=04af59692695ce76f09ef187f5396abf)
The second two charts show the difference in the oil temp. I see a delta of 9°F not county any minor OAT differences. Again two things stand out. First is how flat the oil temp is during the climb and how much lower the oil temp is at the top of the climb with the flaps open.
Click for larger image...
![](/proxy.php?image=http%3A%2F%2Fi62.tinypic.com%2Fiyz8ub.jpg&hash=84312d72cdde054a88221d5cfb6608da)
![](/proxy.php?image=http%3A%2F%2Fi61.tinypic.com%2Fnvthfc.jpg&hash=0e09c73e843d2670451a95ce01f6aae0)
This last graph just shows the IAS from take off all the way to 8500ft MSL.
Click for larger image...
![](/proxy.php?image=http%3A%2F%2Fi62.tinypic.com%2F20paur7.jpg&hash=d3e7bb15698c9ad011d871d69385720d)
So far so good. I expect even better numbers if climbing at something less than 120kts IAS. Hopefully soon I can repeat the test at a slower climb speed.
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