LionChief Engines

It needs to be around 18v of constant power. So crank it up.

Any AC three rail O gauge transformer should work.  If it's not a modern one, make sure you also use a fast acting circuit breaker in series with one of the wires from the transformer to the track. You can often get by with 12-14 volts or so, but you can decide on how fast you want the thing to go maximally, and leave the power at that level.  You can also buy an inexpensive LionChief wall wart power supply from Lionel or one of their dealers. 

Any AC or DC power supply around 2 amps and up will work.  Whether it's a modern one or vintage, it's recommend that you use transient voltage suppression diodes in parallel with the electronics on board the equipment(or as close as possible) for protection from voltage spikes. Breakers will not provide this protection, they are for overloads only.

The LC and LC+, LC+2.0 and even TMCC or Legacy engines will run on lower than 18v - as the voltage drops, features such as smoke generation, remote couplers and speed will reduce function.  BUT- dropping the voltage is a great way to control maximum speed when the little ones are running trains.  You can only reduce that voltage with a variable voltage transformer (as opposed to a wall wart as supplied in starter sets.)

I appreciate all of the replies.  I have come to find out that there is something wrong with the engine.  I was able to test the engine with the track and wall power pack from another LionChief set and still no luck.  It is not getting any power.  The headlight won't even turn on.

Finally got the engine running.  Not exactly sure what the problem was, but I removed the shell and pushed all the wire harnesses firmly together.  Interestingly, the engine did not power up until I put the shell back on.  I am still really puzzled, but I am just happy that the engine is finally running and all the features are working.