Is anyone familiar with this term? It is the method Ford used to create the bead in the exhaust pipe used from 21-27, to keep the front muffler end from sliding too far forward.
Unfortunately, no one is making the correct exhaust pipes for Model T's, ANY YEAR! If anyone is knowledgeable enough to explain this process, I would like to know.
Larry, it is usually done by inductive heating , one end is clamped in a die to remain stationary while the other is pushed by hydrolic pressure to form the ring. Probably dies are used to maintain the correct shape and size. I know truck axles are formed at the hub end by this process as are a lot of pipe fittings and such. KB
The bead must not be very large since the manifold nut has to pass over it. Perhaps it was found to be unnecessary. After all, the muffler is mounted at the other end. How far forward can it go?
Where did you find the info Larry?
I got the information from the original Ford print. You are right about the nut. If the bead is too high, the nut won't slip over it. When I slide the nut, I have it on an angle, and it slides on pretty well. I've been picking up these exhaust pipes for years. I don't think I'll ever need one. I just can't stand the reproductions that are currently available, but the hobby needs them to keep our T's on the road. I might add, sometime ago, I found a NOS 21-27 exhaust pipe. It has the Ford script every 18". One of the best finds I ever made!
Larry - Could you please post a picture of the NOS '21 to '27 exhaust pipe?
Here are a few to hold you over till Larry post some.
I'll be happy to post some photos, as soon as I get the pipe back. I loaned it to a guy who might be able to make them. I'm working on it! The most interesting thing is, it has the Ford script every 18" on the pipe.
What makes a '21 - '27 pipe different from the others?
Up till the time the pressed steel ends on the muffler came out the pipe just slipped into the cast iron inlet end. The 21 to 27 the exhaust pipe ran the full length of the muffler and acted as the small inner tube.
Mark - Thank you for the pictures.
Larry - Ya, that Ford script every 18" sounds very interesting. Authentic reproductions of this pipe would be a joy to use. I bought a repo pipe for my '26 Roadster Pickup and had to cut a notch out of it to get it to line up with the manifold. I'll buy one of the pipes when they're ready.
The following two pictures are from Canadian Owners Manuals.
The Canadian Pressed Steel Mufflers had some variations to the the ones produced in the U.S. ( Note the exhaust exits at the bottom of the rear muffler head, and has a deflector. )
This first one is from a 1921 Overseas edition. ( Note the Cotter Pin ) holding the front end of the muffler.
By 1926 the Cotter Pin had been replaced with the ( Upset Bead ) that Larry is talking about.
Here is another picture of the exhaust pipe. I've had good luck picking them up at flea markets.The second picture is a NOS Ford script muffler end. It came in a box of junk T parts someone gave me.
Great Dan. I'll have to check my muffler ends, and see if any have the script! BTW, has anyone ever seen a script pack nut, I never have?