The Cessna 120-140 Association Forum

Currently have a vacum pump on my 120. Can I convert back to venturi's? Or add the external venturi's and be able to turn them off via a ball valve as a back up? Kinda like the look of the external venturi's. I can't find the part numbers in the IPC for the 3 venturi's.

There were no vacuum gauges offered as options on the 120/140s. You can find venturis at places like Univair or Aircraft Spruce. You may find their performance lacking. Quite frankly, if you already have a working system, and you want them for looks, go ahead and stick them on, but I wouldn't even bother to hook them up.

Why three? Get an electric T&B for redundancy. You can fly needle, ball and airspeed with a total vacuum failure, and you can fly off the vacuum instruments with a total electrical failure.

A 9 inch venturi should run a DG and AH. If you want two (one for each side) get two 4" venturis.

Is your plane certified for IFR?

There you go, John- showing your age with that "needle, ball and airspeed" stuff!
The "dible" made me do it again. Merry Christmas to all.

4004 wrote: ↑Fri Dec 13, 2024 11:53 pm There you go, John- showing your age with that "needle, ball and airspeed" stuff!

It's the way I was learned!
Merry Christmas to all!

I thought John was more familiar with one of these.