Fitting a warped exhaust manifold

[Allan]

It can be done.
This is the exhaust manifold from the barn fresh tourer I am working on returning to the road. It is not as warped as some, as the front three ports are still in line.

To enable fitting the bent manifold, I make offset glands like this.

I cut one gland ring from a piece of exhaust tubing and fit it into the manifold. This photo shows the offset needed.

The two pieces are the tack welded together and the offset checked.

By tacking on one side only, the offset can be adjusted to suit the need by twisting the two pieces before welding them together around the inside.

Then all you need is one of the copper rings from the vendors to go on the offset gland.

I am not ready to fit it just yet, as I am waiting on some brass freeze plugs.

Sorry about the mixed up photos, but you get the idea I hope.

Allan from down under.

[Norman Kling]

Looks like it might work. At least it's worth a try and less likely to damage the manifold than it is to try to straighten it. If it seals the exhaust it will save you from having to ship a new one to your area.
Norm

[George House]

That looks like a good idea Allan. Thank you for sharing it.

[John kuehn]

That’s an idea that’s been a long time coming. I thought the same thing several years ago.
Off set rings could be made and sold by the vendors. But as you would need a market for them to sell for the the maker to sell at a profit. And yes all manifolds are warped a little different than others and that’s a challlenge but it’s worth doing for a lot of them.

It will definitely work. Thanks for sharing!

[TWrenn]

That’s an idea that’s been a long time coming. I thought the same thing several years ago.
Off set rings could be made and sold by the vendors. But as you would need a market for them to sell for the the maker to sell at a profit. And yes all manifolds are warped a little different than others and that’s a challlenge but it’s worth doing for a lot of them.

It will definitely work. Thanks for sharing!

Great idea but not to be a Debbie Downer, I highly doubt there'll be enough market for that. Just sayin'

[John kuehn]

That would be the issue. Seems like something like this idea was in tinkering tips years ago. But since the repo exhaust manifolds came along at a fairly reasonable price it tempting to buy one which I did for my 21 Touring. But I do have some decent warped originals I saved just in case!
But it would save a lot of money to do what Allan did if a guy could do it. And as I said it’s a good idea.

[Steve King]

Allan, I completely understand your attempt to use the used manifolds we have and admire your ingenuity. From an economic standpoint and I realize shipping might be a bit pricey for you, but those copper upset seal rings I see you are using are $39 at Synders and the manifold is only a bit more than twice for $90. When I have exhausted my straight manifold supply I will probably order new. We are actually lucky to have them available, not as lucky with camshafts.

[speedytinc]

I like it!!
Thanks for all the pictorial effort.
Another tool for the repair toolbox.

[Allan]

Steve, those manifold rings are far cheaper direct from the Australian manufacturer. In addition, their robust construction means they can be used over and over, so the cost can be spread.
This manifold was not as bent as some, as the front three ports were all in line still. Usually I have to line up the straight edge on the two centre ports. This usually shows the front down a bit, and the back port more so. I then follow the same process to make two offset gland rings to make the necessary corrections.
You are correct about expensive shipping to Australia, making the purchase of a reproduction manifold a considerable investment. The new ones are nice and they fit well, but they do not look like the majority of originals, so I prefer to do the work to keep things original. When I get the freeze plugs I can show the manifold fitted.

Allan from down under.

[Craig Leach]

Thanks Allan for fallowing up with this. I will defiantly try that next time a warped manifold presents itself.
Craig.

[Erik Barrett]

Well if your time is worth about $5 per hour I guess it makes sense compared with the cost of a new manifold. When you get done you still have mismatched ports which impede flow and probably poor threads for the pack nut. But you will have the satisfaction of saving an original part that others would have scrapped so that means something.

[Allan]

Eric, by the time We pay postage and convert to AU$, that $90 reproduction manifold and the postage to get it here works out at approx AU$250. At $5 per hour labour, That would give me 50 hours to do the fix. I can assure you, it took nowhere near that. I would be surprised if the reduction of flow was measurable on a standard T with a standard exhaust system.
I have fitted a couple of repop manifolds which owners have supplied. They were of different shape at the rear, were a bit bulkier, had no Made in Canada markings, no manufacturer"s branding and no casting bumps. One of those would look most out-of-place on this old car.
Besides, I enjoy the challenge.

Allan from down under.

[James Yuill]

Alan...Great innovative idea. That's why I like this forum.. sharing ideas and brainstorming to come up with solutions. Exhaust flow won't be impacted to any extent. Good job Alan!

[Erik Barrett]

Allan, that makes more sense. I missed the fact of your location. Anyway, it’s a very resourceful solution to the problem. That kind of innovation is good, especially when dealing with parts that are not available new. Nice work.

[Allan]

It"s on. The copper one piece glands needed some massaging. They fit a little too well. Thankfully they are thick enough to take some filing. Tha back port has two thicknesses of the green three hole type gaskets. Being isolated from the exhaust by the gland ring, it holds up well in this application.

You can see why a new manifold would look out of place on this engine.
Allan from down under.

[Steve Jelf]

I've had good luck straightening warped manifolds, depending on how bad they are. If they're more than 1/8" out of line, success is less likely.

[Allan]

On this manifold the front three ports were still in line, just the rear one warped downwards. Usually the warping starts at the front and gets progressively worse towards the rear. Then I put the straight edge along ports two and three to see how far the front port and rear ports are down. That allows me to make two offset glands to accommodate the two out of line ports.

Allan from down under, where good manifolds are scarce.

[tvw]

Well if your time is worth about $5 per hour I guess it makes sense compared with the cost of a new manifold. When you get done you still have mismatched ports which impede flow and probably poor threads for the pack nut. But you will have the satisfaction of saving an original part that others would have scrapped so that means something.

Some of us would GLADLY spend time in our shop at $5/hr or less before we spend a few bucks on aftermarket, reproduction modern metal.
Impede the flow? Model t? REally?
Thanks Allan!