Muffler Rebuild - tips / tricks ?

[fireheadman]

Was able to salvage my cast iron ends.... would like to reuse them with a new shell kit (3-bolt).

will see if I can get a little more knocked off them, then maybe paint them with high-temp paint (black)

So if I go with this kit...

Are there any tip/tricks to getting a good seal?
Would you use something JB Weld High or Extreme Heat epoxy on the ends?
...maybe a jam nut on the ends of the bolts..

[fireheadman]

I am also aware of the pre-made mufflers w/o the cast iron ends.. These are pretty price competitive as an option, but in my case... since I have decent ends, I'm wanting to keep as much original parts as possible (more of a sentimental value since I know my grandfather touched them)

[Allan]

From photos of repro shells posted here at times, they are not made with the correct folded seams. The joint overlaps and is spot welded to hold it together. Some add their own welds along the seam so they don't blow apart. I could send you the two larger ones correctly made with folded delivery seams, but the beautiful new tariff would add $80 to the cost. You know who to thank for that.

Over lapped seams leak, shells leak at the ends the pipe leaks at the front end, so a coat of high temp exhaust paint will make them almost disappear from view.

Allan from down under.

[DHort]

I had a muffler like that with those ends. It was starting to rust so I tossed it and
installed a Stanley tractor muffler. It works great. They used to be $20, but are now
up to $58 or so.

[mtntee20]

A word about tractor mufflers.

I put a tractor muffler on our delivery. It required extra parts and engineering. Nothing expensive or too difficult. My wife complained about the noise. The muffler also leaked. NOT bad, but enough that you could see a bit of carbon at the leak points.

To satisfy my wife and see how much difference there was between the tractor muffler and a Ford muffler, I replaced the tractor muffler with a Ford muffler.

The noise difference was immediately noticeable. My wife is pleased as am I. I totally recommend a proper Ford muffler.

I have not worked with a 3 bolt muffler, but I have rebuilt a 1 bolt Ford muffler with success. My FIRST. Leakage was minimal, equal to any other Ford muffler.

On an open car / truck, I believe normal leakage is not a problem. On a closed car / truck, leakage should be minimal or addressed so as to ensure no potential exhaust build up inside the passenger compartment, to protect the occupants. Are closed cab Model Ts air tight? NO. Air and exhaust are able to enter / exit easily in some and not so easily in others.

[Daisy Mae]

Your cast iron ends look to be in great condition. Give them an overnight soak in something like Ospho to help descale
(Might be anal, but after soaking in acid I always neutralize by following up in a water bath with baking soda, then rinsing). Paint as you will with high temp..

I recently bought a new shell kit for my '14 3 bolt cast iron ends.
First thing I noticed was the shell bows out at the seam sufficiently where a tight seal would not be attained, creating a major exhaust leak at both ends.
I did NOT want to use something more permanent/hard like JBWeld to fill the gap, that just spelled major hassle down the road in my mind. I used a high temp RTV (way easier to remove than JBWeld, but also flexible)... I used Permatex Optimum High Temp RTV. Hopefully I never run too leaned out to glow that muffler past 750 degrees.

Perhaps others have different solutions....

[Steve Jelf]

Spot welding worked for me. No more cobbling the thing back together out on the road. I knew it would last for years, and if it eventually went bad another new one wouldn't break the bank. I would spot weld that one too. A man's gotta do what a man's gotta do.

[fireheadman]

Your cast iron ends look to be in great condition. Give them an overnight soak in something like Ospho to help descale
(Might be anal, but after soaking in acid I always neutralize by following up in a water bath with baking soda, then rinsing). Paint as you will with high temp..

I recently bought a new shell kit for my '14 3 bolt cast iron ends.
First thing I noticed was the shell bows out at the seam sufficiently where a tight seal would not be attained, creating a major exhaust leak at both ends.
I did NOT want to use something more permanent/hard like JBWeld to fill the gap, that just spelled major hassle down the road in my mind. I used a high temp RTV (way easier to remove than JBWeld, but also flexible)... I used Permatex Optimum High Temp RTV. Hopefully I never run too leaned out to glow that muffler past 750 degrees.

Perhaps others have different solutions....

IMG_20250826_121253.jpgIMG_20250826_121245.jpg
Screenshot_20250826_115157_Chrome.jpg

this looks promising!... thanks for the info.

[mtntee20]

Ben,

IF you haven't been told: DO NOT MOVE THE SWITCH FROM MAGNETO TO BATTERY!!!! MAGNETO TO OFF ONLY. Going from magneto to battery has resulted in backfires that will blow your muffle apart. Doesn't happen all the time but there are many on this forum that will confirm the event. With your 3 bolt muffler, you may or may not be OK. Better to NOT find out.

Terry