MTFCA Forum

I am experiencing poor idling (26 T with Kingston L4 carb). When I spray carb cleaner on either intake port area, the engine stalls momentarily. I have ordered replacement glands/rings. I will inspect the block and manifold when I get things apart. Question is has anyone used "goop" of some sort on the gland to improve the seal?

(Note: Lang's advised that the three-in-one gaskets are on back order with no estimate on availability)

I have never used gasket sealer on a Model T intake manifold and I have never had any problems. When you take the manifold off use a good straightedge to check to see that it's not warped. If it is warped, any decent machine shop should be able to true it up for you.

Never mind, I saw manifold sealing and mind went to exhaust.

I've never seen a warped intake manifold and cannot imagine what it would take to warp one sufficiently where a common gasket set (with the exception of the $2.50 paper set) did not seal it just fine without resorting to machining.

Leaking intake manifolds nearly always are a product of multiple failed attempts of wrassling both the exhaust manifold and intake manifold simultaneously, and a couple of failed torques of the clamps, followed by more fiddling and movement. Copper gaskets will NOT withstand dings or misaligned failed installations and still seal when everything finally falls together.

All of this screwing around is generally caused by a bent exhaust manifold refusing to line up properly and relying on the clamps to just mash it all together.

While I believe in saving or reusing all original parts possible, I readily make an exception on the exhaust manifold. The reproductions are excellent and will pop on easily. They can be steadied by the two outboard clamps set vertically and the intake manifold can be set in place once and secured by the two inboard clamps. Messing with a bent exhaust manifold can lead you to want to burn the car to the ground before the day is out. Save your matches and buy an exhaust manifold if you need it and make the job quick, easy, and painlessly.

With a good straight exhaust manifold, you can use the original style individual copper ring seals and make a very nice neat job of it.

Adding to Scott's mounting description - I set my intake manifold FIRST using the method Scott stated above utilizing 2 clamps vertical thus verifying the intake is SET then I attach the exhaust being able to look down over the top of the exhaust manifold again verifying it's seating onto the rings & block.

The exhaust manifold is a new reproduction part. Best I can tell it fits fine. I drilled a piece of angle iron and bolted it to the two center studs to hold the exhaust manifold in place. That may be an over kill but don’t think it will now go anywhere when I remove the outer clamps and the intake manifold. The glands/rings should be here soon so I will see if that fixes things.

I use a pair of manifold clamps with 1 ear removed. Clamp them on both far ends, snugly, horizontally on a STRAIGHT exhaust manifold.
Place intake (using ring & gland type). I can feel it snap into position & give a visual look behind exhaust. Add clamps from the intake out. Replace "tool" clamps one @ a time.

As a backup, I bought what appears to be a very good intake manifold, no rust, clean carb interface and nice ports (all based on photos). It may go in the spare parts pile if not better than what I’ve got already.

One possible thing to look for is a gland which is too wide. When it is pressed into the groove in the block and the groove in the manifold it will not allow the gasket to compress. So check it out before you install the gasket and grind off a little if it is too wide. This often happens when the block and the manifold have been re-surfaced and the glands are then too wide to fit.
Norm

Norman Kling wrote: ↑

Fri Jul 23, 2021 1:01 pm

One possible thing to look for is a gland which is too wide. When it is pressed into the groove in the block and the groove in the manifold it will not allow the gasket to compress. So check it out before you install the gasket and grind off a little if it is too wide. This often happens when the block and the manifold have been re-surfaced and the glands are then too wide to fit.
Norm

Once tightened up, make a visual check for consistent ring crush.

Thanks for all the inputs

Do the repop exhaust manifolds have the same tendency to warp or sag that the old Ford ones do? I put one on the '23 years ago and while it fit fine & works well, it did not look quite the same as the stock one did.

Paul

Hudson29 wrote: ↑

Fri Jul 23, 2021 2:17 pm

Do the repop exhaust manifolds have the same tendency to warp or sag that the old Ford ones do? I put one on the '23 years ago and while it fit fine & works well, it did not look quite the same as the stock one did.

Paul

If you dont use rings, it will warp. Repops? I would bet on it

I install manifolds the way Scott described with the two outer clamps set vertically with nuts run down finger tight. This holds the exhaust manifold in place while you install the intake, no cut-off clamps or other special tools required. The exhaust manifold on my '26 is slightly warped so I could only use two gland rings. I machined two solid rings from pipe and placed them in ports two and four. This left the manifold slightly low at number one port and slightly high at number three. Using the copper sandwich gaskets this has worked well for several years. I never liked those copper crush rings because they're so tiny. Your mileage may vary.

If the manifold is badly warped the above may not work. Bob
.

I recently had an intake leak due to a new "high volume" intake manifold that lacked clearance with the exhaust manifold. The car idled well and did not change speed with LP or flammable fluid sprayed at the contact areas, but missed at cruising speed and the rear plugs were lean looking. Filing off less than 1/10 inch allowed the glands to "click in" on alignment testing. Make sure your glands are not so short they prevent the rings from engaging the ports, and not so long they prevent the rings from compressing. I have heard that the high volume intakes are prone to this problem.

If you have a vacuum leak shoudnt spraying carb cleaner on the manifold make the engine speed up? Is the carb cleaner non-flamable? Do you have the mixture that rich to start with?
Craig.

Just a few observations.
Repop big bore alloy intakes almost never fit as bought. Every one I have fitted has had to be worked on where it comes close to the exhaust manifold. A die grinder will remove enough material to allow a proper fit.
I use the suggested half clamp trick, mounted horizontally to hold the intake in place while wrestling the exhaust. These clamps can be tightened to actually hold the manifold there. When I tried the whole clamp mounted vertically, it cocked the manifold towards the block at the top, and the finger tight nuts allow it to move if it is bumped.
EVERY exhaust manifold must be fitted with 4 gland rings. If not, it is free to go walk-about during repeated heat cycles, and never return to its original straight condition.
Allan from down under.

Allan wrote: ↑

Fri Jul 23, 2021 10:04 pm

Just a few observations.
Repop big bore alloy intakes almost never fit as bought. Every one I have fitted has had to be worked on where it comes close to the exhaust manifold. A die grinder will remove enough material to allow a proper fit.
I use the suggested half clamp trick, mounted horizontally to hold the intake in place while wrestling the exhaust. These clamps can be tightened to actually hold the manifold there. When I tried the whole clamp mounted vertically, it cocked the manifold towards the block at the top, and the finger tight nuts allow it to move if it is bumped.
EVERY exhaust manifold must be fitted with 4 gland rings. If not, it is free to go walk-about during repeated heat cycles, and never return to its original straight condition.
Allan from down under.

I had used a stock clamp, But found the modified clams work way better as Allan explained.

Running timing too late for operating conditions will overheat the exhaust manifold, which can lead to warping and other problems. It also strains the joints between the block and the manifolds. Running fast for extended times with the carburetor extremely lean can aslo cause the manifold to run hotter than normal.

It's been my experience that spraying carb cleaner around the intake ports will always cause a miss even though there is no other evidence of an intake leak. Agree is makes no sense but that's been my experience.

Beyond just running lean due to the vacuum leak, there is a discontinuity of air flow within the manifold due to differences in pressure drop in the fore and aft ports. Running richer to make the vacuum-leak cylinders fire at some speed cannot ever balance the disrupted flow within the manifold, so everything is screwed up more than you can imagine.

The spray cleaner acts more as a very temporary sealant in the gap and now the air flow through the carb becomes more normal, while the semi-constant flow within the manifold (as designed) begins to act more correctly. This in turn causes the previously lean cylinders to see a huge dump of fuel since the carb is far too rich and the engine isn't able to digest it quickly.

Applying raw propane to a leak will cause the opposite effect as the extraneous air flow (vacuum leak) will continue, but now not just air, but a mixture with a very potent combustible material freely flowing into the engine through the leak. Most of what would combust in the fluid application would have been the propellant, but the liquid as mentioned above pretty much occludes it's entry.