The Z4000 is MTH's version of a ZW. It can provide 400 watts compared to the ZW's 275. However, if you overload it, the circuit breaker will trip and no damage should occur to the transformer.
It's listed as being compatible with Standard Guage, so I wouldn't worry about using it with your prewar stuff.
Here's their manual: http://extranet.mth-railking.com/pdfapp/pdfs/instruction/20AS15530I.pdf
Yeah the Z4000 is a 400W transformer. 0-22VAC. Current rating is either 4A or 12A (there are 2 breakers on the side, dont remember which one is for the track power and which is for aux power). It should have more than enough power to run your prewar stuff. I think the problem comes in with changing directions, and that the Z4000 is putting a digital signal on the rails when you push buttons. Your best bet here is to call MTH or post your question on the Classic Toy Trains forums.
Probably find more people that have this stuff on the Clasic Toy Trains forums. MTH would be the final answer. That thing is pretty massive, so I would assume it has enough power for the older motors. Not sure why it wouldn;t be able to run the older stuff, assuming it has enough capacity. Depending on what the reversing switch does on the Z400 - if it just cuts power to cycle an E unit, it's probbaly ok, but if it sends electronic signals to operate an electronic reverser it may be something to avoid hitting when running the old stuff. Same with the whistle. Neither is likely to damage the locos, but the Z4000's electronics might not like it.
I have some pre-war O27 that was given to me, naturally the transformer, being 70+ years old, is not exactly safe to use. I was under the impression that pretty much any AC transformer with sufficient capacity could be used. The old Lionel motors are actually universal motors - I've run my Dad's old Scout loco on a DC power pack, of course the E unit had to be cut out and you can't reverse, but it ran. Can't do that on the pre-war, it has a whistle tender and the whistle would blow continuously. Definitely need AC power.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Hello all, I just purchased a Z4000 and I have 3 newer MTH locomotives, a Super 381, 381E and a 1835E steamer. I know that I can use my Z4000 to power these new locomotives. But, I also have 25 or so Prewar Lionel standard gauge locomotives. Will the Z4000 be able to power these locomotives without frying the boards on the Z4000. I will told by the hobby shop I bought my Z4000 that I cannot use it with old Prewar Lionel Standard Gauge trains. Any reason why not?? I also read online that if it has an AC motor, the Z4000 can power it. All my Prewar Lionel Trains have AC Motors, not DC. I emailed MTH,yet to hear from them. I hope I can find the answer on here. Thanks, Jeff. TCA member since 2005.