Exhaust Leak at Manifold

[Professor Fate]

Does anyone know what the proper measurement of the steel gland rings are for intake/exhaust manifolds? Im looking for how thick they are from front to rear surfaces.
I have rings that do not allow copper rings to seat properly.

[Allan]

Dan, where is the leak? if it is at the usual suspect, the rear port, your block/manifold may be eroded due to previous leaks. Narrowing the steel gland will allow more crush on the copper ring, but if you tale too much off, tightening the clamps will be trying to induce a bend inwards of the exhaust manifold. I would be investing in a set of the thick, one piece copper glands/gaskets and using some exhaust manifold sealant to help.
Others will have different ideas.

Allan from down under.

[Steve Jelf]

The stock rings are .280". I use them with the stock copper crush rings and find the combination quite adequate. The stock rings and gaskets also cost less than half the price of the one-piece coppers. Especially on a block that has any pitting, I smear a bit of hi-temp RTV on the copper to help it seal. Allan's suggestion of taking a little off the rings may help, but it would have to be very little. They have to stick out past the coppper gaskets to align with the holes.

A common problem with exhaust manifolds is that they are often warped, making it difficult or impossible to fit all four rings. The cure for that is to straighten or replace the manifold. I straighten, because that's easier than finding a good original, costs less than new, and because the only new ones being made are the 1925-1927 style.

More about straightening is here: http://dauntlessgeezer.com/DG82.html

[speedytinc]

Your manifold must be straight. These rings dont allow for much variation. They also prevent the manifold from warping. Check with a straight edge.
There are other potential factors @ play. Was the block or manifold surfaced? Is there some built up carbon in the ring recesses?

[DanTreace]

I have rings that do not allow copper rings to seat properly.16-54563-1.jpg

The variables with the manifolds need to be addressed. Determine if the port recesses in the block and the manifolds are clear, not pitted or filled with crusty iron or carbon, clean these as square as possible for a full circular seat.

Typically, fully cleaned port recesses in both block and manifolds will almost swallow the steel gland rings, leaving a tad sticking out to hang the manifolds. Most times you have to spread the ring gap to make a grip for the rings to stay in place and not freely fall away.

Only the slightest rim of the steel rings needs to be in either side of the manifold ports, that makes lots of room for the crush copper gaskets to seal themselves when fastened tight with the clamps.

[speedytinc]

I have rings that do not allow copper rings to seat properly.16-54563-1.jpg

The variables with the manifolds need to be addressed. Determine if the port recesses in the block and the manifolds are clear, not pitted or filled with crusty iron or carbon, clean these as square as possible for a full circular seat.

Typically, fully cleaned port recesses in both block and manifolds will almost swallow the steel gland rings, leaving a tad sticking out to hang the manifolds. Most times you have to spread the ring gap to make a grip for the rings to stay in place and not freely fall away.

Only the slightest rim of the steel rings needs to be in either side of the manifold ports, that makes lots of room for the crush copper gaskets to seal themselves when fastened tight with the clamps.

I wonder if the rings, in other cases seem too short, could be assembled & given a partial squeeze to narrow the copper ring in 1 port @ a time. A small precrush on 1 intake port with an intake manifold to all 6 ring/gland sets.

[Professor Fate]

Thank you all...
After supper I'm headed out to check the exhaust manifold and make sure it hasn't gone whoopie on me. It's a repro I got from Lang's.
My motor is clean and straight. The intake/exhaust ports are all clean.
I got .028 for a measurement also.
Stand by for news/updates.

[Professor Fate]

All 4 cylinders leaking on exhaust side. Manifold is straight and true. All steel rings are .028.
I'll just try and install again. Maybe 3rd times the charm.

[George House]

Dan,
You’re saying ALL FOUR EXHAUST PORTS are leaking ? The repro exhaust manifolds are excellent parts. Whats not been discussed is your installation technique. You’re not attempting exhaust manifold installation in tandem with the intake manifold, are you ? Best to install the exhaust manifold tightening the first and last manifold clamps then inspect from the top for good seating. Then the intake with the interior 2 manifold clamps. Lastly, reposition the fore and aft clamps to press on both manifolds.

[Jerry VanOoteghem]

All 4 cylinders leaking on exhaust side. Manifold is straight and true. All steel rings are .028.
I'll just try and install again. Maybe 3rd times the charm.

Measure the depth of the counterbores in the block and in the manifold. Compare the width of the gland ring. Not uncommon for the mounting face of the block to have been machined by a past rebuilder, leaving the counterbores too shallow to accept the gland ring without bottoming out. If you don't have the tools to measure accurately, then just fit up the manifold, using the glands only, with no crush rings. This is a trial fit, to see if the manifold will touch the block, (or at least come close enough to compress the crush rings), before bottoming out the glands.

Just to be clear, and since I don't know your experience level with Model T's, when you say the manifold is straight, do you mean that the face of each port is coplanar with the others, or that each port lies in a straight line with the others. The latter is the one to check. When manifolds warp, they tend to arch up, pulling the centerlines of the middle 2 ports higher then the end ports. But again, maybe you already knew that.

[Scott_Conger]

you cannot use the seals over and over and I am thinking that you might be trying to

[Professor Fate]

I reused the gaskets once.
The manifold is flat, straight, and true.
And I have been installing all at once, not in phases as stated.
I'll be making some changes to my approach given your recommendations. Thanks!

[Scott_Conger]

This guy's approach is about as good as it gets and requires no special tools: https://www.youtube.com/watch?v=8fMYStzhqhg

Note the final force this guy used to clamp everything down...heed what you see. You don't need excessive force and if you think you have trouble getting things back on, you haven't seen trouble until you pull out a manifold stud.

[Steve Jelf]

No wonder you're having trouble making things fit. Your engine is the wrong color.

[Professor Fate]

I picked "snot engine green" accidentally on purpose. Although I wanted the darker forest green, the store only had this horrible shade when I needed paint.
Here are some pics of my '26 speedster project.

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