ASA EZ Cool Flap Data Point

[Brantel]

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...




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...





This last graph just shows the IAS from take off all the way to 8500ft MSL.

Click for larger image...


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.

[Brantel]

Here are a couple more that show the CHT and OIL temps at the top of the climb:






Top of climb Delta of 20°F on CHT

Top of climb Delta of 12°F on OIL Temp

[jeremiahd]

Nicely done tests...well performed and documented. Thanks for the data and analysis!

[PerfTech]

... We wish to say thank you to Brian for all the work gathering and posting his information on our "EZ Cool Flaps". We know this requires a lot of work and we wish to say thank you as it helps us and others with this product. Allan and ASA staff...

[Sylvainsting]

Hello,

I know it is an old post but I'm still trying...
I would like to install EZ cool flap on my RV7. Do you have some pics about your installation ?
Is it mandatory to install 2 cool flap or one is enough ?

In advance thank you
Sylvain

[Brantel]

Originally Posted by Sylvainsting

Hello,

I know it is an old post but I'm still trying...
I would like to install EZ cool flap on my RV7. Do you have some pics about your installation ?
Is it mandatory to install 2 cool flap or one is enough ?

In advance thank you
Sylvain

Best I can remember, here is what I have:

http://www.vansairforce.com/communit...lap#post898136

I put in two and don't regret it. It looks symmetrical. Have no data on just putting one in.

The only complaint I have had is the original hinge cracked in short order.

[crabandy]

Brantle,
Curious if you know the sevo?s recommended operating temp specs on the EZ-Cool flap? Also how many hours and if any servo failures?
Thanks,
Andy

[Sylvainsting]

Thank you for your reply. I read a lot of your posts when you installed yours 4 years ago..

I have some other questions :

-Did you have some issue with the electric engine (with hot temperature ?)

- Is there somebody who installed some cool flap on a St James cowl ? I think there is a thickness difference with the standart Van's Aircraft cowl..

-Is it possible to connect the cool flap on a VPX ? I already have some free switches on my panel, connected to my VPX..

In advance thank you
Sylvain

[PerfTech]

Originally Posted by Sylvainsting

Thank you for your reply. I read a lot of your posts when you installed yours 4 years ago..

I have some other questions :

-Did you have some issue with the electric engine (with hot temperature ?)

- Is there somebody who installed some cool flap on a St James cowl ? I think there is a thickness difference with the standart Van's Aircraft cowl..

-Is it possible to connect the cool flap on a VPX ? I already have some free switches on my panel, connected to my VPX..

In advance thank you
Sylvain

?.Perhaps I can offer up some answers to these questions or concerns. On our
very first run of this product, we used an aluminum hinge that produced a few
failures. We immediately converted to a stainless hinge that is several times
stronger and thicker than the aluminum one. We have had no failures since
the changeover (Over 2,300 units in service). These now have many thousands
of hours in use, with very very few failures of the electronic actuators, and no
mechanical failures. Most of the few actuators that needed replacement were
due to the wires being pulled hard, damaging the unit. We have not seen any
temperature related issues, but I still think it prudent to shield them from
radiated exhaust heat when mounted in close proximity to the exhaust pipes.
If so desired when installing, one can elect to use any DPDT switch to operate
the EZ Cool Flaps that possibly fits your needs better than the supplied switch.
Every aircraft is a bit different, but in general most people elect to install a pair
of flaps, as you will never get too much cooling. One will usually drop CHTs
by about 20 to 25 Deg. and two will drop things by 35 to 40 Deg. Unlike cutting
the exit air cowl forward, or adding louvers that will be costly to your cruise
speeds (sometimes as high as 10 Kts), you can have all the cooling advantages
of cowl flaps with no downside. This is why virtually all certificated general
aviation aircraft are designed and produced in this configuration. I hope I
have satisfied your questions, and do appreciate your inquiry. Thanks, Allan..

..PS; Please keep an eye on our website as we have several new and exciting
products coming very soon!..

[Brantel]

Originally Posted by Sylvainsting

Thank you for your reply. I read a lot of your posts when you installed yours 4 years ago..

I have some other questions :

-Did you have some issue with the electric engine (with hot temperature ?)

- Is there somebody who installed some cool flap on a St James cowl ? I think there is a thickness difference with the standart Van's Aircraft cowl..

-Is it possible to connect the cool flap on a VPX ? I already have some free switches on my panel, connected to my VPX..

In advance thank you
Sylvain

I have not had any failures of the servo. I did wrap them in reflective aluminum tape during original install.

Mine are fed from a circuit on my VP-X Pro. I do not use the VP-X to control them, just to feed them power.