Manifold leak

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Model T Ford Forum: Forum 2010: Manifold leak
Top of pagePrevious messageNext messageBottom of page Link to this message  By M. C. Hawker on Monday, August 30, 2010 - 02:29 pm:

I just took my 1927 C-cab TT out for its maiden voyage Saturday. First time I have driven a T and things went exceptionally well.

The truck is original, in unrestored condition but otherwise is in excellent condition.

A problem arose when putting her back in the trailer. An exhaust leak at #4 cylinder opened up. The rest are OK.

Question...Is this leak due to a warped manifold or just a leaky, blown gasket? Replacing the gasket is not a real problem but if the manifold has warped slightly I think the type of gasket set I buy might be critical.

Yes, I can remove the manifolds and check for straightness but I would rather hold off on disassembly until next week after I take the 94 year old son of the original owner for his first ride in her in 40 years.

How about some constructive opinions as to what I should do. Any suggestions on the proper gasket set to purchase? (Langs number)?

Has anybody had any luck planing the manifolds on a mill? How about putting pressure on the exhaust outlet with a turnbuckle and over time draw the port in straight?

Tony


Top of pagePrevious messageNext messageBottom of page Link to this message  By Brian Dudley on Monday, August 30, 2010 - 03:21 pm:

The issue with the warped manifold is not that they bow on the mounting faces, but that the #4 port actually wants to drop. Do a search on the forum and I know you can find some pictures that will illustrate how they warp and how to check them.
They are very easily checked with a straight edge and if they are warped there is really nothing you can do to straighten them.

Now... it will not hurt it to run it with a leak, so if you want to take your freind out for a drive first, by all means... do so.

The first thing to check for is if you can see what type of gasket is on it now. If you can see any sort of paper, fiber or steel material spanning the ports, then it is one or two piece gaskets that you have on there and are not original. If you see nothing by quick visual inspection then most likely they have the original style copper rings with steel glands on them.

The original setup is very good and seals well. The steel gland compresses and fits into the hold in the block or manifold and then the copper rings goes over that to seal between the two parts. When they crush, they seal.
The steel glands keep the manifold from warping because it holds it in place on all 4 ports.
You cannot use this style of gasket if your manifold is warped because the #4 port will not line up with the block.

If you have the large gaskets that span multiple ports, then you might very well have a warped manifold. These are usually the type used for when you have a warped manifold because they will seal even if the ports do not line up. But, they usually do not last long (especially the paper ones) and there is nothing to keep the manifold from warping more.
But if you have this type on there, it doesn't mean that your manifold IS warped.

Before you order any parts, take the manifold off and check it with a straight edge. If the bottoms of the round ports all line up with each other, then order the original style gaskets and put it back together.
If it is warped, either order new multi port gaskets or find a new manifold.

Also, it isn''t a bad idea to get a new brass pack nut when you do the job too. Sometimes they don't want to tighten down well after they have been used too much.

As for warped manifolds, that usually happens becasue your fuel mixture is too lean.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Norman T. Kling on Monday, August 30, 2010 - 04:20 pm:

Exhaust manifolds can indeed be straightened. There are several old posts which explain how to do it. However, for about $100 you can get a brand new one. you will be surprised at how much more power the car will have when all the ports line up. A partially blocked port affects the back pressure. Go ahead and drive the son of the original owner, it won't be a problem. Then you can decide whether to use the flat gaskets with as many rings as you can get in place, straighten the manifold, or replace it.
Have fun.
Norm


Top of pagePrevious messageNext messageBottom of page Link to this message  By M. C. Hawker on Monday, August 30, 2010 - 04:48 pm:

Thanks guys. One of my concerns was the possibility of eroding the port openings from the hot flames. The engine was rebuilt sometime in the 50's with stainless steel valves. From what I can see the present gasket is a tan looking compressed? paper about 3/32" thick. It is blowing out a pinhole opening at the top of the manifold large enough to allow flame to shoot up, so that means the manifold has sagged down?

When I get the stop and tail lights wired the old girl is good to go! Man, what a good feeling!

Tony


Top of pagePrevious messageNext messageBottom of page Link to this message  By Robert Conner on Monday, August 30, 2010 - 05:28 pm:

After looking at some photos of warped manifolds, I think the term is more like sagging, I'd say you'd be better off buying a new as cheap as they are and having a backup that if you want to you can fix later.

Has anyone tried making some sort of hanger to take the weight off the rear of the manifold? It looks like the whole problem could be avoided if there was a better way to secure it to the block.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Norman T. Kling on Monday, August 30, 2010 - 07:56 pm:

There are offset bores in both the block and the manifold in which steel rings are to be inserted. You should have 6 steel rings one for each port both intake and exhaust. If they are used, the manifold will not sag. If the last one is left out, the rear will sag, and if it is placed but the two center ones are left out, the rear will sag and pivot raising the center of the manifold. Whether you re-use the existing manifold, install a new one, or repair the existing one, you should attempt to place all 6 rings. At least place the front and rear ones. The flat gaskets will seal leaks. They should also be used with the steel rings, but they won't help a bent manifold.
Norm


Top of pagePrevious messageNext messageBottom of page Link to this message  By M. C. Hawker on Monday, August 30, 2010 - 08:21 pm:

I know this is a dumb question Norman. I understand the use of the steel rings, but what about these upset copper rings I see listed? Are they required, optional depending on the type of gasket used or what? I understand steam and hit and miss engines and old farm tractors but the Model T seems to be a breed into itself!

Tony


Top of pagePrevious messageNext messageBottom of page Link to this message  By Brian Dudley on Monday, August 30, 2010 - 08:43 pm:

The steel rings go inside ports and the copper rings go around them to seal the surface when the manifolds are clamped down. You will understand when you get them.

If it is the paper type that you ahve on there now, I am surprised it is only leaking from one spot. Those usually just fall apart causing many leaks.

The ports will not get corroded by the exhaust leak.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Hal Davis on Monday, August 30, 2010 - 08:46 pm:

The copper rings ARE the gasket with that type set up. They are a little harder to install because you have six copper rings, six glands, and two manifolds to hold in place with one hand while you tighten the clamps with the other. BUT....it can be done. However, this set up requires a good straight manifold.

There is also a copper 3 in 1 gasket set that comes with the steel gland rings. It is a little easier to install. You don't have to use all the gland rings if you can't get them in there due to a little warpage. However, what's gonna keep the manifold from warping more if there's nothing to hold it? Kind of a catch 22.

Don't confuse this second set up with the copper 3 in 1's that have a built in copper flange on one side. I don't know what that does for you. Whether you put the flange side toward the manifold or toward the engine, it can still slip along the other surface. May as well not have the flanges, in my opinion.

I recently installed one of the new manifolds with the original style copper rings and steel glands on a friend's car. I was working alone and was able to get the job done. The manifold was well made and fit nicely. The job would have been easier with an extra set of hands, but like I said, it can be done.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jerry Lewin on Tuesday, August 31, 2010 - 04:33 pm:

Hal, You say the new manifold you installed for your friend was "well made" I have had two manifolds that had to be returned to the vender because of faulty machining. I am now gun-shy of ordering another one. Are you aware if there may be more than one manufacturer? Also have you heard of others having received bad manifolds?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Gary H. White on Tuesday, August 31, 2010 - 06:39 pm:

I had two ports badly corroded by exhaust leaks. They were that way when I got the car. Got leaks temp. stopped by using the heavy duty copper rings with raised ridges and an additional ring cut from an asbestos gasket on correded ports. Vaporizer manifold, if origional?, was not warped. Block now at machine shop getting properly fixed.
Gary


Top of pagePrevious messageNext messageBottom of page Link to this message  By Norman T. Kling on Tuesday, August 31, 2010 - 07:48 pm:

The copper rings seal the best if your manifold is straight. But if it is warped, you won't be able to get them in all the ports. In that case use the flat gaskets, the ones with 3 ports each and use as many rings as you can get into the exhaust manifold, which will be at least 2 and maybe 3. Try to use one ring in the rear port to keep it from dropping more.
Norm


Top of pagePrevious messageNext messageBottom of page Link to this message  By Allan Bennett on Wednesday, September 01, 2010 - 10:36 am:

I am with Norman. The manifolds must be installed with the six gland rings if you are going to keep everything in shape. They are essential in holding the exhaust manifold so that it can't sag. However, you can fit a bent manifold and use all the gland rings.

The sag seems to me to be cumulative. Rather than just the no4 exhaust dropping, most times no3 has dropped a little too. If you line up your straight edge on no2 & 3 ports, you will usually find no1 is a little low and no4 is more so. I make up two offset gland rings to compensate for this. I cut two gland rings from a piece of exhaust tubing. Place one on the end of the length of tube you cut it from, and offset it as much as the manifold port has dropped. Weld around the inside, not neccessarily continuously. Then cut off your tubing so you have a gland ring with a step in it. Repeat the process using an offset to match the other port. I cut individual gasket rings from the 3 in 1 gaskets which come in the engine gasket set.
When ready to install the manifold, install the two centre rings first. Then put the offset rings in their respective places and position them so that they match up with the sag in the manifold. I smear a high temp exhuast sealant around each gland and then put a gasket ring in place. Another smear of sealant against the gasket and you are ready to bolt it up.

I note that some are of the opinion that the restriction this may cause will be detrimental to the performance of a T motor. I have no way of quantifying this, but have not noticed any discernible difference. Doing it this way allows one to re-use an original part which looks correct rather than the bulky repros with their quality problems.

Allan from down under.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Nevin Gough on Wednesday, September 01, 2010 - 11:30 am:

I have a repro on mine that seems to be identical to the original so not sure how you can describe it as bulky. Quality is 100 percent. I would recommend one based on my experience.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Hal Davis on Wednesday, September 01, 2010 - 11:41 am:

Jerry,

I really have no experience with them other than this one. There may, indeed, be more than one manufacturer. This one came from Smith and Jones in Columbia, SC.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Allan Bennett on Thursday, September 02, 2010 - 04:57 am:

Nevin,
There must be more than one repo manifold. The ones I have seen are much bulkier in the casting and at the back it is squared off and ugly! Perhaps it was somebody's attempt to beef it up to prevent warping?

Allan from down under


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