The Cessna 120-140 Association Forum

My C-85-12 has a problem. I bought my 140 last spring. I just noticed
the exhaust stack on Cylinder #2 is rubbing the intake tube on cylinder
#4. My exhaust is the straight pipe model with a shroud over each
down-pipe. Both of these are non-flexible and I am worried about
one or the other rupturing in due time. The situation is not serious
yet. The engine has rebuilt cylinders installed about 150 hours ago.
Any ideas on how to achieve separation of these two. Just need a
little space there?

Off hand I'd say the exhaust stack is bent, or has been repaired incorrectly. Can you post a picture?

John, Turns out I find that exhaust stack was repaired some years ago
and the new weld probably created the problem. I can see no answer than
to remove the exhaust and get it reworked.

The other problem is finding new metal shrouds for my straight pipe 140.
No-one seems to be making them.

Vince

vinceo wrote: ↑Sat Oct 12, 2024 11:06 am John, Turns out I find that exhaust stack was repaired some years ago
and the new weld probably created the problem. I can see no answer than
to remove the exhaust and get it reworked.

The other problem is finding new metal shrouds for my straight pipe 140.
No-one seems to be making them.

Vince

I have a decent set of straight pipes if you can't get yours welded. Shipping would probably be expensive. $60.........ish or so I would imagine. Finding good straight shrouds ............used........will take some time. Post in here and in the parts section. You are correct, no one makes them. Your best bet is salvage yards. Try Todd at Smokin' Rivet in Eau Claire Wisconsin. He specializes in 120/140 aircraft. He may have a whole set?

I may need to take you upon that. The exhaust stack was repaired some time back
I seen in the logbook. The repair added thickness to the stack so much so that it rubs
right up on the intake tube for #4. Other than taking it off and reducing metal on
that stack, which I don't want to do. I don't think there is a fix.

I will get back to you after I decide. I will try and remember to take my camera
with me and photo this.

Thanks
Vince

Attached is a photo of the situation. The two components are solid. There is no sign of metal "working" as there is no dust or metal particle traces but regardless there should be a small space between the two.

Looks to me like that stack is broken! Rubbing is the least of your problems.

Thanks, regardless its coming off for full evaluation.

Take the straight pipes off and send them to Dawleys. They will fix the problem. The shrouds are another issue. Don't have an answer.

I am not familiar with Dawleys but a quick search....looks like they have been taken over by
Tailwind Technologies in 2021. Thanks for the tip.