Edison Spark Plugs.

[jiminbartow]

I know the Edison #14 spark plug fits the Model T. Are there any other numbers that will fit the Model T? Jim Patrick

[TRDxB2]

I know the Edison #14 spark plug fits the Model T. Are there any other numbers that will fit the Model T? Jim Patrick

Theses link of a previous discussion has lots of other plugs - make a list?
https://www.mtfca.com/phpBB3/viewtopic.php?p=267955
https://modeltfordfix.com/model-t-spark ... nthusiast/

[Steve Jelf]

There are many Edison plugs on eBay. But Edison plugs came in many sizes and models. I would pass on any eBay ad that fails to identify which Edison plug is being offered. Model T sizes (13 and 14 I believe) are getting very scarce, while many other sizes remain relatively common.

[Wayne Sheldon]

Wonderful to see you posting here again Mr. Jelf!
And right you are. The Edison 13 is a somewhat larger plug and requires a larger than standard T plug wrench. However its most important distinction is that the base is a dual fire. Whether dual fire has any real advantage or not is still debated. Although most automotive engineers seem to believe the advantage is minimal at most.
The Edison 14 is about the size of a common Champion X, and regular single fire base.

Both the Edison 13s and 14s changed in details over the years. some can be taken apart, and some cannot be. The size and placement of ridges varies as well. Putting together a set can be difficult. I have three Edison 13s I have been trying to find a fourth for a set for thirty years now. Now the problem is also that I took one of them to a swap meet years ago to try to match it, and somehow misplaced it when I got home. A household move since has had either the single, or the pair show up at different times. But it has been almost twenty years since I have seen all three of them at one time.

[CudaMan]

If anyone has one or more Edison 13 plugs, I would happily trade you an Edison 14 one-for-one. No, I will not sell any Edison plugs outright.

[signsup]

Interesting how Ford, Edison, and Firestone walked arm in arm through history.

[TXGOAT2]

I think it's difficult to get a "dual fire" plug to actually fire to both ground electrodes under operating conditions. There are almost always small differences in the gap or electrode profile that will allow one electrode to fire at a lower voltage than the other. That is the electrode that will fire, unless you have a VERY hot coil. One advantage that a dual electrode plug might offer is that, having two electrodes, the one that fired most would erode first, and at some point the second, un-worn electrode would begin firing, assuming it was gapped within the correct range. I believe the principle use for dual or triple electrode plugs was in large stationary engines that ran all the time, or most of the time, such as a mill or powerplant engine. In those applications, a plug might perform for a very long time before needing any service or replacement, thus avoiding shutting down and re-starting the engine.

[CudaMan]

I believe Pat is correct about the spark jumping to just one ground strap at a time. That didn't stop manufacturers from trying all sorts of ground strap configurations.

[Arnie]

Steve:

We are glad to see a posting by you!

That indicates you are getting better.

Good for you and we hope you keep on improving!

Andy & Arnie

[RVA23T]

Nothing is new under the sun.
They still try this multi point spark crap today they are called e3 and don't for get these bosh plugs that would lose the tip out of the electronics!

[CudaMan]

I'm resurrecting this thread to up my offer - I will trade TWO Edison 14 plugs for ONE Edison 13 plug.

Why?

Because I run Edison 13s in my 1912 Flanders, but I have no spares.

I run Edison 14s in my 1924 Model T, but I have some spares that I could trade.

Still not selling any Edison plugs outright, just offering to trade as outlined above. No, I won't trade for any other obscure plugs you may have lying around.

[Manuel]

I have 2 old Edison spark plugs still in their packets. They are; HC72 & HC82. Would anyone be able to tell me what they fit?

Manuel in Oz

[CudaMan]

Try asking these folks: https://spcoa.net/

[Manuel]

Thanks CudaMan.

[CudaMan]

A fellow member has stepped up and is trading me two nice Edison 13 plugs for four of my Edison 14 plugs, Thanks Tad!

I should have enough Edison 13s now, so I don't need to do further trades.

[Tadpole]

Nice trading with you sir, I’ll look forward to seeing them in your Flanders!

[Tadpole]

On the topic of spark plugs for T’s with multiple electrodes, the only one I know of that always makes multiple sparks is the aptly named Twin Fire.