Underslung Exhaust Pipe

[The Riot]

I replaced the exhaust manifold during the restoration of my 72 Cub, and had to use a reducer for the flared 90 degree connection. Now my underslung pip won't fit anymore without hitting the touch-control rockshaft and the hydraulic flowlines.

Has anybody ever had this issue before and how did you deal with it? Also, does anyone know where to find a new piece of 1-1/4" straight exhaust pipe? It looks like I might have to do some custom bending to make it work.

Thanks,
The Riot

[staninlowerAL]

If you can get this to a custom exhaust shop, they have a tubing bender that can probably fit the pipe to your manifold connection. Stan

[bob in CT]

You used the later style manifold, I presume. IH made 2 pipes and I think you just found out why.
107 139 C1 is the pipe for the later manifold that requires the reducer.

[artc]

probably better to replace the manifold with the older one than buy the pipe for big $$$

[Bob McCarty]

When I was looking to have a local muffler shop bend several underslungs, none had the tooling small enough to handle 1 1/4". They suggested several motor cycle shops who couldn't do it either. Time for the correct manifold apparently.

Bob

[Barnyard]

When I was looking to have a local muffler shop bend several underslungs, none had the tooling small enough to handle 1 1/4". They suggested several motor cycle shops who couldn't do it either. Time for the correct manifold apparently.

Bob

Several years ago I went to the biggest muffler shop in our area. They bend all their pipes. I had the same result.

[Bill Hudson]

We put a hydraulic bypass block on my friend's Lo-Boy and had clearance problems with the exhaust pipe. The solution was to go to a local race car builder and get a short piece of tubing (the builder has a multitude of various sizes of round, square, and rectangular tubing of various gauges) that closely matched the exhaust pipe OD. By cutting the exhaust pipe and rotating each end to get the clearance needed, then welding the new tubing to the exhaust pipe the problem was solved. For those wanting an "original" look, this is probably not a desired solution. For those interested in "functional," this should work fine.

Bill

[bob in CT]

Along the line of Bill's suggestion, I have bent pipe by making slices with a hack saw and making the bend and then moving on to the next until the fitment is tuned. Then weld up the slices, which ideally will have no gaps if you are careful. The exhaust on my Sunbeam Tiger goes right through the frame rails and it has to be perfect or it will rattle. I did the entire front section in this way including adding an H pipe. Saved me from having to flatbed the car to a shop while I was in the middle of assembly.

[Doodle]

A Electrician company will have a metal conduit bender that would probably work

[leerenovations]

This might be a little too redneck for you, but when I was younger I helped bend a bunch of tubing into intricate shapes for a yard art project. We bent the tubing without collapsing it by filling the tubing with sand. The sand fills the tube so that it wont collapse but you can still bend it because the sand inside is flexible.

[The Riot]

Here's any update.
I took the muffler off of the pipe and hooked up the pipe to the manifold nipple with the clamp very loose. I then was able to wiggle the muffler onto the pipe and again loosely attach the u-bolt at the muffler mounting bracket.
The good news is that I have it all together but it's all under stress and still bumping into the hydraulic lines and the TC rockshaft.

My next move is to try and bend some electrical conduit and I think I will try the Redneck technique with sand that Lee recommended. I'm always interested in trying something like this myself.
Stay tuned, I'll let everybody know if I can make it work.

Thanks to all
The Riot

[Clip]

Sand bending is a time-tested technique. I read about workers bending 12" steam line by filling with sand, packing both ends with paper to keep everything right and heating with acetylene torches before using chain falls to pull to shape. I've tried before but haven't had enough dry sand (wet makes steam) and the patience to pack pipe full of sand, so I went with the slice and weld technique.

[Doodle]

Conduit is a good possibility. The owner operated Electricians have some good benders. Conduit is of course galvanized so it will throw off some white gas and flake off when heated. Maybe let the Cub run a long time to burn this off before painting. I have sucked in a lot of these gases torching and welding on grain bin equipment since a young age. Probably just one of the reasons for short breath. Maybe stand way back outside and drink a while it does its thing.

[Jim Becker]

Conduit is of course galvanized so it will throw off some white gas and flake off when heated. . . . I have sucked in a lot of these gases torching and welding . . .

I have experienced that sort of thing, both from galvanized and cad plated, usually when I forget about it and start welding something I shouldn't. The two produce different gases but have similar effects. I strongly encourage everyone to avoid this situation.

http://www.anvilfire.com/iForge/tutor.php?lesson=safety3/demo

[The Riot]

I've seen electrical conduit many times but had never taken note that it is galvanized, but I see it now. This causes me concern about the safety issue and now I'm rethinking my plan to use conduit.

Does anybody have any idea where IH might source the small pipe they use for these exhausts? Right now I would like to find the correct size and correct metal in a straight section and do some custom bending, but I shying away from the conduit because of the galvanizing.

Thanks again,
The Riot