Running Marx and Lionel trains together

Last Updated on October 26, 2019 by Dave Farquhar

Someone asked (not me specifically) whether it’s possible or desirable to run Marx and Lionel trains as part of the same layout, what the caveats are, and how to do it.

It seems to be a pretty dark secret. The answer is, yes it’s possible, and yes, it might very well be desirable, but it’s possible to run into some pitfalls.

Let’s talk about it.Marx and Lionel competed in the 1950s. While Lionel strove to be a status symbol, Marx had a product for every niche. Anyone could afford a Marx train. And since Marx track and accessories were compatible with Lionel, sometimes they got mixed.

Is it desirable? Sure. Both Marx and Lionel made things the other didn’t. For example, Marx made a nice Missouri Pacific cattle car. Lionel made a Missouri Pacific box car. (The Lionel MoPac car wasn’t as nice as American Flyer’s rendition of the same car though.) And if you’re not a high roller, you can buy Lionel O27 cars (which was Lionel’s cheap stuff) and Marx 3/16 scale O27 cars (which was Marx’s expensive stuff). They’re the same size and look fine together. And both can be cheap. I pay between $5 and $10 apiece for Lionel “Scout” type cars from the late 1950s or 1960s. It’s easy to pay $50 apiece for modern O scale cars.

Lionel and Marx used incompatible coupler designs, but that’s easy enough to fix too. Take your most beat-up Marx car and your most beat-up Lionel car, and drill out the rivet that holds one of the trucks in place on each. Then put a Lionel truck on the Marx car and vice-versa, secured with a nut and bolt. Swap the wheels around if you need to in order for both cars to sit flat. Now you can run Marx and Lionel not only together, but even as part of the same train.

The problem is that a lot of Marx engines–basically everything but the Marx 1829 and the Marx 666 (I’ll just call it the sixty-six from here on out) locomotives had what they call a “fat wheel.” The gears that drive the wheels on most toy trains are in the side of the wheel. On Lionels and the aforementioned Marxes, those gears are smaller than the diameter of the wheel. On all other Marxes, those gears are nearly the size of the wheel.

So what? Well, it’s no big deal if you have a simple loop or figure 8 of track. But if you want your track to have branch lines with switches (also called turnouts), where the train can go off in another direction on a different stretch of track, and you use a Lionel switch, the cheap Marx engines like the 400, 490, and 999 will do crazy things when they hit it. Hopefully they won’t fly too far off the track.

Marx switches are designed for Marx locomotives, of course. The problem is, most Lionel locomotives can’t maintain electrical continuity while they go over a Marx switch. Lionel spaced its electrical contacts differently from Marx. Sometimes momentum will carry the Lionel through the switch and it’ll go on as if nothing happened. But sometimes the momentary loss of power is enough to engage the Lionel sequencer, causing it to either go into neutral (in the case of expensive Lionels) or reverse (in the case of cheap ones).

Flip the switch on the top of a Lionel locomotive to disable the sequencer (also known as an e-unit), and you can run Lionels through Marx switches all day.

You can also modify a Marx switch by inserting some track pins strategically to close down the gap that impedes the Lionels. Simply insert track pins where indicated in the diagram below.

The downside to this is that it limits you to O27 track, but that’s not really a downside–you can get wider-diameter O27 track. Use wide diameter track and then your trains will run just as well, or better, than they would on the costlier O31 track.

You can even go outside of O gauge for rolling stock. If you run across a postwar S gauge American Flyer car and like it, it’s possible to adapt it for use with Lionel and Marx. O27 is supposed to be 1:64 scale, just like S gauge is. So if you run across some Flyer cars and the price is right, consider changing its trucks out for Lionel and adding still more variety to your fleet.