Cowl Flaps

[svyolo]

Chris, for me that is a reason enough not to do it. On an air cooled engine, you can only leak oil or fuel. Either leaking on the windscreen is a disaster.

[RatherBFlying]

Battson how did you actuate your cowl flaps? I don’t want to use an actuator, and am struggling to find certified examples for inspiration.

[Battson]

TimTall's post below shows a similar setup to mine, except I used the push/pull with threaded rods at the ends, instead of wire ends. So I used clevis ends instead of the wiregrips.

[huntaero]

Here is a couple pics of my cowl flap installation. We fly in temps from 100f+ to -10f on floats wheels and skiis so cowl flap is a must. Used a Ray Allen actuator PN B6-11T

[TimTall]

I used this dual end push/pull cable...https://acsproducts.co/our-products/...-lock-control/

With these wiregrips at the ends...

https://www.aircraftspruce.ca/catalog/appages/wiregrip.php?clickkey=3009106

There's a white knob to the right of the mixture control pushed all the way in to open the flaps. Works great mechanically and I have very good temperature control. IMG_6017.jpg IMG_6022.jpg

[svyolo]

As I go down the path of cowl flaps, do the "airplane" piano hinges work smoothly if curved, like the bottom of the cowling?

It is funny, the Vetterman exhaust is a thing of beauty. The Cert pilots that I know oogle over it. But it has a glaring thing I wonder about. Right where the air exits the cowling, I have these two huge muffler/heat muffs blocking the air. I am no expert on these matters. But I am having a hard time looking at those and not thinking they are a huge blockage/drag for the whole enigne cooling system as a whole. Luckily, they are aft of a flex joint. I may experiment with that.

[Bcone1381]

That is insightful!  I will consider fabrcating a shield to smooth out airflow around them and attach it with steel hose clamps  like I do my heat shields.

[rodsmith]

My cowl flaps are higher on the sides of the cowling, the hinges are somewhat curved and still work smoothly. You are right about the mufflers, they don't help with getting the air to exit efficiently.

[svyolo]

Thanks, I will use them.