Who is running a venturi vacuum system on their Aeronca?

Post by **joea** » Sat Jan 03, 2009 13:08

Trying to get some input on venturi vacuum systems on Aeronca's.

The Sedan I am flying has dual 4" venturi's on it right now, and wondering if I can get by with removing one of them and cutting the drag by half in this area. They produce loads of vacuum right now.

The plane has a artificial horizion and DG that uses vacuum and thats it. The old turn and bank has been upgraded to an electrical version, so that cuts the need for vacuum in the plane.

Does anyone run a single venturi in their airplane and if so, what all do you run with it?

Thx,

Joe A

WWhunter · Post by **WWhunter** » Sat Jan 03, 2009 15:52

I only have one on my 172 and I think it runs the DG and Horizon. If I remember the T&B is electric. Never had any problems.
Keith

colie85857 · Post by **colie85857** » Sat Jan 03, 2009 20:10

2" venturi for 1 gyro, 4" venturi for 2 gyros, 9" or 10" venturi for 3 or more gyros.

sedanpilot · Post by **sedanpilot** » Sun Jan 04, 2009 18:49

I have a singel 2 inch, but I am still stock with respect to the gyros, only a turn and bank. I think the exception to the rule above is the Artifical Horizon, it takes more volume. A 4 inch can handle two vacuum insutruments like a turn and bank or a DG, but the artificial horizon takes a 4 inch on it's own.

See Aircraft Spruce :

For the 4" venturi:
This venturi develops 4"Hg suction from double- throat venturi and 10" long horn. Used to operate a directional gyro or gyro horizon. When operating directional gyro theres sufficient capacity to also operate a turn/bank. All aluminum construction. May require a suction regulator. Wt. 0.9 lb.

The bottom line is you could go to a 4 inch and a two, or a single 9 inch, or leave it alone.

Remember that venturi tubes ice up just like carburators in the clouds.

Post by **joea** » Wed Jan 14, 2009 11:01

SP,

Damm! Thanks for the info. Guess as long as I keep the artificial horizion I am stuck with the two 4" venturi's.

Not much ice in Arizona flying but know what you mean. Frankly I get all the IFR flying that I ever want or need flying for my job, so with the Sedan its strictly "day VFR."

Thx,

Joe

sedanpilot · Post by **sedanpilot** » Sun Jan 18, 2009 00:02

I know what you mean, I don't really like having the tube out there either. Look at the bright side, it makes the airplane look retro