Spark Plugs

[Sal]

I was looking at the list of spark plugs on http://www.garbee.net/~cabell/PartsCross.PDF ,and I was wondering what the difference was between the Autolite and the Champion Plugs? I found that the price for the Champions was more then double then for the Autolite's. Is the Champion a better plug?

[Lifer]

...I was wondering what the difference was between the Autolite and the Champion Plugs? ...Is the Champion a better plug?

You will probably hear a lot of claims that one or the other is better. In actuality, there is very little difference between the two plugs. I mean, there are only so many ways you can configure an electrode, an insulator, and an anode and come up with a spark plug. Both plugs come in a variety of heat ranges, both are available through most parts houses (as a special order, 'cuz they won't be "on the shelf")

Some may insist that one or the other is "the only stock plug." Which one is "correct" is also a moot point, as both were installed at the factory. Sometimes, an engine came off the line with both kinds on it if the supply bin began to run low and someone restocked it with whatever was available at the time.

[cuz]

There are several subtle differences in plugs between manufacturers and between a late and early model plug of the same manufacture. The OEM plug depended on which plug manufacturer that truck builder was affiliated with or had strong ties to. Jeep was an Auto-Lite user and GM was a AC user with some Champion. The military didn't care but contracted many plug manufacturers to produce the M series plugs to the MS standard. So in the field any brand could show up in any engine.

As to which is better today well that depends on who you ask, what they are driving and how they drive it. Either plug meets the Mil Std and will give adequate performance in a 45 - 50 MPH truck.

The Auto-Lite can be found on the shelf in the larger cities. Smaller towns can usually get them in overnight for you. Prices are $6 to $9 a plug.

[ZGjethro]

I ordered Autolite 2246 plugs from the same chart. I was looking for a hotter plug due to carbon buildup. When I got the 2246 plugs, my spark plug wires would not fit into them due to the ceramic core that is different from my 2245 plugs in use. Has anyone had a similar problem? I would still like hotter plugs but I don't know the number to buy

[Sal]

That was the reason ZG why I was looking at the chart in the first place I was looking for a little hotter plug for the same problem. That's when I had seen the price difference between the Champion and Autolite .You said the ceramic core insulator on the 2246 plug prevented you from putting your wires on HOW ?

[cuz]

The chart you are referring too is most likely the Auto-Lite heat range chart that aligns the plugs by heat range and not physical construction. The barrel lengths and ceramic insulator lengths and barrel end thread lengths and sizes vary in that list.



The 2243, 2245 and 2247 are your only three Auto-Lite choices for our applications which are listed in spec MS35909-1, -2, & -3.

The 2242, 2244, 2246 are an entirely different plug and conform to spec MS35908-1, -2 & -3.

[ZGjethro]

Thanks Cuz. I did not know about the military specs you listed. I went of the other chart. The chart I was referring to was the one Sal posted (www.garbee.net/~cabell/PartsCross.PDF). It listed the 2246 as the next hotter spark plug in a list of M-37 replacement parts. You can check it out from Sal's link. The 2246 differs from the 2245 dimensionally at the top. The ceramic insulator comes all the way to the top of the plug and the metal casing is thicker, or rolled over. The spark plug sealing insert will not fit into the 2246. I will try the 2247.

[Sal]

So then Cabell's cross reference charts wrong when it lists the 2246 plug for our application. I wonder what else might be wrong on this chart ?

[cuz]

I wouldn't say wrong. I'd say it has an error in the plug list. I believe you'll find the 2246 is for PE type stationary engines.

Remember, Cabel's chart is a work in progress that has been around several years. Most of us that downloaded a copy several years back have made many pen & ink corrections and additions to it. Perhaps we can interest Cabel in an updated version by sending him copies of our changes.

The preferred and designated plug for the M37 is the 2243 or AR5S or XMJ14 (MIL SPEC MS35909-1). Note there is no equivalent AC plug. The only two hotter plugs with identical specs are the 2245 (AR7S or XMJ17 or WR46) (MIL Spec MS35909-2) and 2247 (AR9S or XMJ20 or WR47) (MIL Spec MS35909-3). The better chart to use is the chart developed by Dennis Spence and found in the Portrayal Press printing of his lists of applications for Army parts.

The MS35908- spec calls for a longer plug with full length barrel porcelain insulator whereas the MS35909- calls for a shorter plug with 3/4 high porcelain barrel insulator.

[Sal]

What about the Champion Plugs. Cuz is there a chart for them ?

[Sal]

I have it Cuz.. When i saved the chart you posted I seen the rest of it showing the other plugs.. Thanks

[cuz]

These are similar pages from the 1987 Champion Catalog

http://img.mypicgallery.com/jeep-electr ... er-key.jpg

http://img.mypicgallery.com/jeep-electr ... -chart.jpg

This new forum chops the photos in half when they come up.

[Joe]

I was looking at the list of spark plugs on http://www.garbee.net/~cabell/PartsCross.PDF ,and I was wondering what the difference was between the Autolite and the Champion Plugs? I found that the price for the Champions was more then double then for the Autolite's. Is the Champion a better plug?

Champion advertises a LOT more than Autolite does so their plugs are a lot better known but I've ALWAYS found that Autolite plugs run much better in my 30+ Mopars. But I haven't had my M-37 long enough to try out the different manufacturer's plugs in it so it might be an exception to that rule but I'd be surprised. It's easy enough to get a set of each and try them, that's what I did in my other Mopars.

As far as GM using Champions and Dodge using Autolites, that's probably just because of who the two manufacturers sub-contracted with. I know that MOST if not all of the electronics in my '51 m37 were made by Autolite. (Generator, lamp housings, gauges, v. Regulator, distributor, etc.)

My 2 cents worth,

[Sal]

ZGjethro. Did you ever get those Autolite # 2247 spark plugs for your truck ?
Sal

[ZGjethro]

Sal, I have not ordered the 2247 plugs yet. I am currently doing house projects and the truck is running well right now.