Best way to remove exhaust pipe

[ShawnAgne]

Going to remove the exhaust pipe from current motor and put it on the new motor. Guessing it is on there pretty tight, so was wondering what is the best way to go about removing it.

[clm2112]

Do you have the vertical or under-slung exhaust?

Vertical is a piece of cake... just go get a piece of black iron pipe, cut it to length, screw it into the manifold, and ignore the old one

Under-slung is a little more of a challenge. Hose the clamp bolts with PB-Blaster, or your favorite penetrating oil, and wait. Then try to disconnect the exhaust pipe from the elbow on the manifold. Mine came right off with just a little squeeking. The U-bolt on the muffler under the axle came off with no issue at all. As for the elbow on the iron intake/exhaust manifold... good luck. Mine is still rusted to old manifold and I gave up trying to remove it.

[ShawnAgne]

It is a vertical. Is the thread a standard thread like I'd find on iron pipe at Lowe's?

[Urbish]

Yes, you can buy a stub of pipe from your home improvement/hardware store of choice. It's either 1" NPT or 1-1/4" NPT (tapered pipe thread). See this post regarding the difference: http://www.farmallcub.com/phpBB2/viewtopic.php?f=1&t=15608

I would add that I was able to remove and replace the vertical exhaust pipe from the manifold on my 1946 B without much issue, even though it appeared to be permanently rusted in place. I wire brushed where the pipe meets the manifold to remove loose rust flakes and bathed the joint in PB Blaster. I waited about an hour, soaked it in PB Blaster again, and it unscrewed easily with the help of a pipe wrench. If you do decide to remove your old pipe, be cautious of how you load the wrench. If you get rough with it, you could break the manifold.

[Matt Kirsch]

Usually the pipe is rusted in so badly that you won't get it out without breaking the manifold. When it rusts enough, though, you can usually break off the vertical piece and use a cold chisel and hammer to collapse the threaded part out of the manifold.

That pretty much means the end of the pipe, though. No putting it on the new engine.

As others have said it is a standard size piece of pipe you can get at any hardware or big box. Stock is what's called 1" black iron pipe. Some replacement manifolds have a 1-1/4" threaded hole in them, which you would reduce to 1" using a reducer bushing.

Be aware that 1" and 1-1/4" don't actually measure that, either inside or outside. 1" pipe is actually almost 1-3/8" in diameter, and 1-1/4" pipe is actually over 1-5/8" diameter.

[Bob McCarty]

Here's a how to in case it's stubborn: viewtopic.php?f=141&t=21985

Bob

[ShawnAgne]

I'll just get a new pipe. Its going on a 184 motor that I'm putting on the cub, so I'll check but guessing I have the larger manifold.

[Puffie40]

For a vertical pipe, One option is to trim the pipe so it sticks out of the hood about 2 or three inches, and hold a muffler or piece of exhaust pipe on with a muffler clamp.

It's not seamless looking, but it gives you some convince if you have to pull the hood - just unbolt the clamp and pull the pipe.

[leerenovations]

Also to clean ther threads, buy a pipe nipple and cut cuts in the threads to make openeings. Put a rag inside the manifold just lower than the threads. You can then use the nipple with cuts and a wrench to clean the threads. Its makes assembly a lot easier. Don't remember to pull the rag out with all the dropped crap that it ctaches.