The other day while working on the touring I noticed that the plug on #1 had discoloration on the insulator from escaping exhaust. When I touched it I found the insulator was loose in the base. I removed the plug and opened it up, and found that the wide part of the insulator pressed down by the collar was all shattered in small pieces. I replaced the insulator with one that looked good and put the plug back in the car. All seemed normal until yesterday when I was driving home from town and suddenly heard that telltale tick-tick-tick of escaping combustion. Sure enough, it was the plug on #1 again.
Exhaust discoloration under ON.
What I found inside.
Did I just happen to get a couple of bad insulators, or is there something else going on here?
Did you use the copper gaskets.
First one had copper, second had gasket material. I'll try to find a good copper gasket for the next one, but I wonder why the first insulator broke up.
Steve
Was the packing washer ( copper or brass gasket) under the porcelain? If too tight wrenched together, the heat of expansion can crack the porcelain, esp. if the gasket is bad.
Count on Dan to come up with just the right bit of literature. In this case the gaskets were only under the insulator. I'll try it with gaskets above and below and try to be gentle on the pressure.
Steve, Make sure the copper rings are well annealed first!
Steve,
Back in my days in the aerospace testing field, we used soft copper seals between stainless steel bulkhead fittings and flaired end tubing held on with "B" nuts.
The brand name, and the term that we referred to them as, was Voishan seals.
I'm not sure if these are available in a size that is suited to fit a Champion X insulator for a T but, it might be worth looking into. I'm sure a new, soft copper seal might fix this problem.
Good Luck,
Mike.
I was a bit off in my last sentence above. You can only use the gaskets under the insulator. They won't fit over the top.
Arrrggggh! Today I drove about twenty miles before I heard the sound of another busted X. I replaced it with an A-25 to get the car home. All three of these incidents have happened on #1. The radiator didn't boil, but the discoloration of that copper gasket suggests a lot of extra heat to me. Does that make sense? What would cause extra heating on one cylinder?
The copper is discolored because hot combustion gases were passing it after the porcelain broke.
I suspect you are over tightening the nut.
Intake leak, valve lash too tight, etc.
"All three of these incidents have happened on #1."
and
"What would cause extra heating on one cylinder?"
Steve, this is a bit surprising to me as cyl #1 usually the coolest of the four. If that cylinder IS running too hot then Doug's suggestions warrant investigation.
On the other hand, could all of the plugs you installed have been "set up for failure" by a previous owner by over tightening and pre-stressing the porcelain?
Good luck with your investigations. Bill
Maybe you should rotate a different plug to #1 cyl and put the next one you fix in the other cylinder. That may tell weather it is your rebuild of the plug or something to do with #1 cyl causing it. Another thought, have you used the same metal parts each time? Could there be something in the base putting uneven pressure on the porcelain? Jim
I have copper seals both above and below the porcelain, no problem. I hate to think of the steel collar going against the porcelain directly. I also like the annealing idea. Seems there were several variations of copper seals in these things. Some fit better than others.
Here's an NOS Ford Champion X plug disassembled. The box art places it around 1935 - 41.
Here's a 1935 - ish Champion replacement core:
Here is a 1913 - 1922 Champion X core: