The Cessna 120-140 Association Forum

I have a seemingly dumb question. I own a 46 140 s/n 9857 with an O-235-C. I'm not an aircraft mechanic by any means but I keep getting asked this question that I can't seem to answer to my liking.
Why is my gascolator 'upside down'? (Bowl above the lines.)
I see this on many Cessnas and pretty much every 120/140 that I've looked at. There was even a photograph of my engine conversion in the 60's with it this way as well.

Is this just something that Cessna did back then, is there a certain reason for it? All IPC drawings and such show it that way as well.
It seems to really freak out some A&P/IA's.

Thanks for any insight to my silly question!

It is just the design of the way the drain works. If the bowl was on the bottom then water would be at the bottom of the bowl and no way to drain it out. This way water being heavier than gas goes out when you open the petcock.

And, the line feeding the carburetor takes fuel from the top of the bowl.

It makes sense to me, but the comeback always is, the water cannot collect in the bowl because the bowl is higher than the inlet or outlet, so where does the water collect. (Then the added, you should flip that over before you fly.)

I figure it has worked that way since 1946 and it hasn't fallen out of the sky yet, so it must be working.

Most other gascolators have the bowl underneath the inlet and outlets with the drain at the bottom of the bowl.
picture from the STC upgrade in the 60's... I don't think mine has anything except a petcock of sorts on the top, all lines are in and out of the bottom.

DO NOT CHANGE A THING!!! When you do your pre-flight walk around, you will sump the wing tanks and the
gascolator, dumping any collected moisture that settles in the BOTTOM of the system.

Larry Surratt
1946 140
89011
Serial # 8015
26R

7392 wrote: ↑Thu Sep 10, 2020 4:27 pm DO NOT CHANGE A THING!!!

I have no plans to change anything, it is working just fine as it is.
I was just looking for some magic words to help one of my local mechanics understand it better. (And he's an old guy that usually services many historical/antique aircraft.)

The, 'that's just the way it is' and 'its just a Cessna thing' weren't good enough for him.

I do appreciate everyone that has chimed in so far!

The outlet is connected to a standpipe that takes fuel from the top of the glass bowl outside and above the screen. Fuel comes in the shorter pipe, on the inside of the screen. The water separates out as the fuel goes through the screen and fills the bowl. The water stays in the bottom and the clean fuel enters the standpipe on top.
This photo shows the longer standpipe, the outlet, sticking up above the top of the screen.
.

Perfect, Thanks!

Mine is also mounted that way on my O290D. But my IA made me move the primer line up top.

6643 wrote: ↑Thu Sep 10, 2020 7:55 pm The outlet is connected to a standpipe that takes fuel from the top of the glass bowl outside and above the screen. Fuel comes in the shorter pipe, on the inside of the screen. The water separates out as the fuel goes through the screen and fills the bowl. The water stays in the bottom and the clean fuel enters the standpipe on top.

image_212.jpg

This photo shows the longer standpipe, the outlet, sticking up above the top of the screen.
.

img_3076_179.jpg

After almost 40 years of hearing this "upside/down" item questioned and some pretty good attempts at explaining, this is (finally) the best AND the one to copy and keep handy for any doubting owners/technicians in the coming years. (This is the kind of expertise often shared here by John C. and others and that reminds us how important the right info. is in maintaining the airworthiness of our aircraft). Mac