I guess most of us know that there are different versions, but some may not realize there are so many. Looking through a box of plugs this morning looking for the four I want to use on my roadster, I came up with six distinct varieties. There are probably also some I don't have.
The X plugs fall into two main groups: completely take-apartable and not completely take-apartable. #1, #2, and #3 are in the first group, and #4, #5, and #6 are in the second.
I'm guessing that #1 is the earliest plug here. Note that the brand is lower on the insulator than on the next plug. So low, in fact, that REG. U.S. PAT. OFF. is hidden inside the collar. The base extends down about 1/16" lower than on the next plugs. The collar which holds down the insulator is brass, not steel. All the other X's in my stash have steel collars.
I believe #2 is the kind that was used through most of the teens. The insulator has straight sides.
The only difference in #3 is the ribbed insulator. Based on period advertising I've seen, I think it dates to about 1921. It's the last of the fully take-apartable X plugs.
Here's how all the first group plugs look disassembled:
The thread on the center post is 5-40. The base, center post, collar, and lock washer are steel. The copper washer that goes under the insulator originally had asbestos lining which now is often missing. The flat washer that goes on top of the insulator is brass, and so is the nut.
Beginning with #4, the center post is permanently fastened in the insulator. The base extends downward about 1/4" farther than on previous plugs. The insulator is slightly taller than on #3, and the sides are a little more curved under the ribs. Also beginning here, the center post thread is 8-32. Although the post is permanently fastened in the insulator, it doesn't have the crimped-on brass cap that appeared on later plugs. This is the only plug I've ever seen like this, so I gather it was produced for only a short time.
#5 is the X that was produced from the mid-twenties on. It has the crimped-on brass cap and the tapered sides below the ribs.
#6 is the current Champion X. It 's very similar to #5, but very recognizable because the brand is printed much smaller. The brass cap is also slightly smaller.
Eventually I want to do a web page on Champion X plugs, so I'm on the lookout for any that aren't shown here. I'd also like to have dated period ads showing the different versions.
This is the earliest I have. It's from a 1920 LASCO (Louisville Auto Supply Co.) catalog.
Notice the difference in the diameter of the electrodes.
Everyone has mostly praised the X plug but I'm wondering if the good words are for the new ones or a certain vintage one?
Royce, do you have a date/source for the ad? It appears to be later than your early plug.
I will add a couple questions. What is the significance of the "Ford script" Champion plugs? Also the Champion 31s? I also have an early looking Champion "O" which fits a T's pipe thread. (Wish my camera was working okay)
I also have a few Champion (appearing) plugs with no "X", "Ford", or "31". At least one doesn't even say "Champion", but it sure looks like one. They otherwise look like Steve J's number 3. I suspect these are ones that got "generic" porcelain replacements.
Okay, a few questions.
I have a nice set of four early looking Splitdorf plugs similar to Steve's Champion number 1. I am planning to use them for my mostly '13 because I don't have nearly enough early Champion Xs.
Great thread! Thank you again Steve J!
Drive carefully, and enjoy, W2
Here are some primer type plugs
I photographed my ads from Ford Owner and Dealer, Automotive dealer and repairer, and other magazines. Ford used other plug suppliers in production as well, including Mosler and others.
Here are some ads:
1913 Automotive dealer and repairer:
1911 Ford Owner and Dealer:
1912 Ford Owner:
French ad showing the replacement ribbed style and the (then current production) brass top:
The earliest ones have no mention of patent, they predate the 1912 lawsuit which was settled when Mosler was purchased by Champion.
This is a new old stock X plug from the mid 1930's:
New old stock refill from the early 1920's:
Most of these aren't X's but is the number at the lower part of the insulator a heat range?
Steve. I apologize for the lousy photo but I've tried and don't have your wonderful skills or camera and still want to participate.
P.S. I love your Roadster.
Dec 16, 1911
That's a great comparison of the heat ranges Rodger. (X being the hottest) Thanks for posting! Here is your picture with just a little spit and polish.
Actually the early X with the thick electrode would be the coldest. The ones made in the 1920's - 1930's have the thinnest wire electrode which would be the hottest, and thus less likely to foul, but more likely to cause spark knock with bad gas.
My opinion is the earliest ones were designed for the horrible gasoline of the 1909 - 1922 era. As gas got better the electrode could be made thinner for less chance of fouling.
Ken, thanks for the adjustment.
Good point about the gas, Royce.
I had always heard the gas was very good until WWI and then went down hill.
In real actuality, the size of the electrode has nothing to do with it. It's the length of the insulator or tip exposure that determines heat range. The more exposed the electrode, the hotter the plug. The insulator is there to extract heat from the tip.
This explains it.
Midday break. There are some nice ads posted above, but I think a word of caution is in order. We should remember that advertising illustrations, especially when they're drawings rather than photos, sometimes don't match the actual product. Usually the discrepancies are minor, but occasionally you find a real fantasy.
Also from 1914:
Ray there are 4 of those in my 14 right now! Champion H-14 and i have been running them for years.Bud.
I am very interested in the smooth-side Champion X spark plugs.
I have heard that the smooth side x-plug with no made in U.S.A. was used in 11-12, and the made in U.S.A. was used 13-16. Then the ribbed plug came out.
Terry Bond, who is a spark plug collector, sent me the following e-mail and photo of Ford plugs that I have never seen before.
Here are my thoughts on the X plugs with and without "Made in USA."
None of the earliest plugs used that designation. Only when Champion began exporting them did they choose to clearly mark their product in such a way. Interestingly it is not required to do so, and never has been. The Department of Corporations was started in 1909 and in 1914 became what we know today as the Federal Trade Commission. There are several regulations that elude to such markings on exported products, but none that seem to actually require it. So, it became simply Champion's way to let everyone know that they were made in this country, and thus were the "real deal." There was a good bit of counterfeiting and including this was also a way to help ensure you bought the real thing, not some cheap foreign copy.
What makes all this difficult is that advertising we see often is simply artist rendering, no actual photos of the plugs. There were also vast stockpiles of Champion X plugs, even the straight sided ones and a good many of them were even WWI surplus. I've seen ads well into the 30's that offer discount prices on these plugs. I have a collection of auto accessory catalogs from the early 1900s up into the late 20's and early 30's that show them as available.
With plugs, we're not dealing with strict time-lines of production simply because changes in them evolved and there was always a lot of older plugs around in stock and in warehouses. We do know however that the Brass Hat style of Champion plug appeared first in 1916 when Champion purchased the Jeffrey DeWitt spark plug company, chiefly to obtain the rights the sillimanite, which they were mining successfully near their East Coast facilities. It is found mainly in Connecticut, however it is the official "state mineral" of Delaware. It is a superior insulating material and was first used by Jeffrey DeWitt. The design of their plug featured the "brass hat" just at the time Champion acquired them. So, that clearly means a car earlier than 1916 should certainly have the straight sided X plugs. After Champion began exporting, they were "probably" marked with "Made in USA" on them. Prior to then, they were probably just plain "X" plugs.
It is true that a variety of plugs were used. I have a couple of very interesting plugs in my collection including one of the very early Mosler plugs with "Ford Automobile Company" stamped into the steel body. I also have a very rare plug that is a simple 1 piece construction with a very bold Ford script on it. There were a very few of these obtained years ago by one of our collectors in the Detroit area. They allegedly came from someone who worked for Ford and was involved in helping Ford to manufacture their own plugs - a project that never really got off the ground. In the attached photo it's the plug on the far right.
Great post - thanks
I emailed a guy selling old Champion X plugs on eBay who made the same statements you just made. To cut to the chase, Champion did indeed offer brass top plugs around 1916. However, they were not Ford supplied on the Model T until about 1923, from the evidence I can find. In fact you won't find evidence of a brass top Champion X plug being manufactured until about 1922.
I offer you the chance to educate me with proof to the contrary, as I did the fellow selling plugs on eBay who claimed to be an expert in such things.
Take a look at the Champion X advertisements above, and the dates.
I'm with Royce, ready to be educated if I'm wrong. Based on advertising I've seen, I put the first ribbed X at about 1921. It was the last that could be completely disassembled (#3 in the first picture). I agree on the brass cap too. I'd put its first use on Fords at about 1922.
Steve and Royce, I feel the same way. I want to be educated also.
I put the smooth side plugs in when I show the car at a National Meet.
If I try to run them on tour or just running around, they don't last. The gasket material will give up and cause blow by like in Royce's post on Friday August 23.
This might be a solution to the blow-by problem. On the left is one of the new plugs, with its thin little copper ring. On the right is a 1921 plug with the old asbestos-filled ring. In the center are a couple of the copper crush gaskets I bought from an aircraft supply. I'm going to try those in some straight-side X's and see how they do. I'll report the results on the forum after I have a chance to use them for awhile.
Thank you Steve. I will be interested in seeing what you find out.
What did you think about the spark plugs that Terry sent pictures of?