Not always good with my questions I’ll try this question again. If I started with 2 modern Lionel 4-4-2 steamers and combined them into one 4-8-2, would the motor from one of them have enough power?
Probably. The motors never varied in size much. How will you connect the side rods and the shells? If you like solving problems it might be fun but I wouldn’t start hacking until I had a clear picture of what I was trying to accomplish. MTH makes some nice O gauge engines including 8 drivered ones.
I wonder if it would work as a kind of wacky Beyer-Garratt - those were three-part - with the boiler in the centre. Here one would hack off the cab from engine #1 and the pilot from engine #2 and work out some sort of articulation using a wheelset Lock the e-unit in forward for both engines… hmm.
Going off of what Doug said he could acually make a 4-4-4-2 but use both motors . hopefully he could either use one e-unit or that both would work to have the engine going the same direction would be funny thou to watch it fight itself one forward one reverse lol. But probally would burn one or the other up befor to long. The real hard part would be connecting the 2 engines into making one but sure would be neat to see.