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Cabin Vent Options

Eddie Foy

MEMBER
South Florida
Looks like I will be making a new boot cowl for my PA18 certified. I dont like the vent in front of the windshield. I especially dont like how the cable goes thru the firewall twice. There has to be a better way. I will be putting a snap vent in the left front side window.

What say you all? any alternate ideas?
 
Just had to be said.

Why not use the left window? Front or rear. Keeps you from having to poke a hole in a window or fuselage. And no control cables.

Web
 
I have seen a side vent on the boot cowl. I have a vista vent in the side window in front of the slider. If you put one there put it as far forward as possible it will work better. I do open window but it cool the back seat passenger too much. If I was flying down there I would get as much venting as possible.
DENNY
 
Looks like I will be making a new boot cowl for my PA18 certified. I dont like the vent in front of the windshield. I especially dont like how the cable goes thru the firewall twice. There has to be a better way. I will be putting a snap vent in the left front side window.

What say you all? any alternate ideas?
I put a corresponding snap vent on the right side window and one in the front of each D window. The right side front snap vent moves an amayzing amount of air and the back vents when rotated backwards act as exhaust... Works wonders but I wouldn't give up the boot cowl vent at gun point because it cools your feet and helps distribute air from the heater.
 
I do not ordinarily fly in super cold environments. I have never actually used that vent on a Super Cub - but am puzzled as to why cables through the firewall pose a problem? The vent is behind the firewall, is it not?

The Decathlon does have a vent problem - I did a little fiberglas tube to blow air on my nose after the first three slow rolls. Now I need some way to shut it off without spending $300 for one of those eyeball deals.

For normal stuff I just installed those round deals in the window. Point them forward - mucho air. Point them aft - no air. They are simple circles of plastic, bent at about a 30 degree angle to scoop air - or not.
 
I like the original vent because it blows cool air on the firewall. PITA to install in a new bootcowl but once it is done it is done.
 
Location is important. The original location which you want to get rid of has the highest pressure for greater airflow, so is really the best location. The center base of a windshield due to the shape slows down the air velocity increasing the pressure. Stay away from the sides of the wraparound for two reasons. After flowing around the cowling, the air flows away from the sides and the hot cooling air from the engine is there. That air is hot enough so that my Cub gets some heat through the fabric, very warm.

Consider the wing root fairing just below the center leading edge. Make a box with the air entering just behind the windshield with a flap to close and direct the air. Sort of like the Cessnas.
 
It always amazes me that 95% of super cub guy's close the door. WTH. I have hours of ski time with the door open. What are you guys afraid of, falling out.

Glenn

When it's really hot out, close the bottom door, you don't get the hot engine air. Cubcrafters doesn't have the vent on the boot cowl and uses the snap vent. Ask little wing how his works in his cub.

When it gets cold I turn the heater on and then use the factory vent to blow the hot air back. Works well
 
Maybe I can engineer a way to open and close the existing cowl vent without running a looped cable thru the firewall.
 
Change the lever on the vent? Besides going through the firewall twice, that cable has an extremely tight bend in it.

Web
 
Rig your cab heat to be cab cool.


I like that idea. The Tripacer vent on the left side works great, I have it open a little all winter. And if you hook your heat up like I did here it will blast you out of the front seat with the bottom T closed off. Most 10F days I only have half the heat on.

Glenn
 
How about just a pivot bracket made as light as possible? Might be same weight as section of removed cable. Excuse the crude drawing, but you get the idea.

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Or a sleeved push/pull rod if you have a fairly straight shot at it........just kicking some ideas out.

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Piper had a good design in my opinion. The control is high and to the right. It is pulled out to actuate. It is not in the way when actuated. Never seen an issue with the cable looping back through the firewall.
 
Steve,

I have had issues with mine. I dont think it had been closed in a loooong time before I got the plane. Took a lot of cussing and lubing to get it to work. That 180 bend puts a lot of friction on it.

Look at it this way. The vent is open 99 % of the time..That means it it sticking out. Mine was right next to my mixture and in the way when pulled out.

If I attach it to the back, 99% of the time it will be pushed in and out of the way..I can place it near the edge of the panel.

Call me wierd, but I like to minimize the numbers of holes in the firewall.
 
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I was going to ask that. If minimizing the holes in your firewall is a big deal, go for it. Is it that you are afraid that a fire will come through the extra holes?

If I were afraid of a fire in front of the firewall, I promise you I would never set foot in one of these things. I do not think small holes in the firewall filled with wires and RTV will cause additional problems if a fire occurs. You are in trouble from the get-go.
 
The top vent leaks water. Very poor design. Not going back in my boot cowl...
But you live in Alaska where your SC probably lives outside and probably rarely need it. I have not had any leaking issues. I do install new gasket on the vent when riveting together and on the door. Much needed when flying in Texas but I figured not so much in Alaska.
 
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