In a recent post various suggestions were made on how to fit a warped exhast manifold. Most rely on the clamping force only, to keep the back port performing as it should This is, at best, a temporary fix. This manifold was fitted to my 1925 roadster before I fitted a dual manifold.
With a straight edge lined up on the two centre ports, these photos show the extent of the bend at the font and rear ports.
I make up these off-set gland rings to compensate for the bend.
These go in the end ports. With the usual glands in the middle ports, this is how they line up.
The usual copper gland rings can be used for a permanent fix.
Hope this helps someone.
Allan from down under.
I see that will fix the up and down problem. Does it create a left to right situation?
Allan, Looks like a good fix to me. I wonder if the manifold has now reached it’s “happy place” and will not keep on warping with time. Very clever fix to a common problem. Thanks for sharing.
My first attempt at straightening a warped exhaust manifold was a failure. I was careless with the heat and burned a hole in it. Since then I've straightened three successfully and intend to do more. There are a great many available cheap because they sag a bit. If they're otherwise good, I intend to buy some, straighten them, and make a few bucks.
There was a web site where the process was explained, along with the jig needed to do this. But, from what I learned, unless someone is giving you the gas and O2 to use for free it is cheaper to just buy a new manifold. Dan
I cut the manifold counter bores oversize and in line, then made inserts to bring the counter bore diameter back to size. Also took a cut off the faces, so my inserts have flanges to reestablish the manifold height. Haven't got it on the engine yet, so we'll see how she works next Spring.
I was "taught" to hold the straight edge at #'s 1 & 4 on the bottom of the manifold and then you see how much #'s 2 & 3 are out of alignment ?
I bought new manifolds for 2 of my T's. Less than $100 each. I use the rings and so far they have not warped. Before this, I used the 3 in one flat gaskets and one ring in front and one in back. I think this will actually cause a problem with the backpressure when they get very far out of alignment. Cheap fix usually only lasts for a while. Some people have built a jig and they can heat the manifold enough to be able to bend it back in shape. sometimes it will crack when trying to bend.
I've seen that comment about the cost of gas too, and I'm calling bogus. A new manifold (available only in 1925-1927 form) costs $84 plus shipping. There's no way straightening one manifold burns that much gas. In making the jig I spent maybe $50, most of it being $40 for a new piece of I-beam. Here's my experience, with a link to other info:
I check straightness as Steve T says, using #1 and #4. I put steel rings in the two holes and hold a straight edge against them.
This might come in useful to me. New manifolds could be bought once... Now shipping & tax is about 5 times the purchase price it might be worth getting a little more life out of the manifolds.