W. Murderface

Why not connect the motors with aluminium cables as well?

For wheeled vehicles at least, I think there's the possibility to increase the protected volume by moving the motors away from the hull and into the wheels. As for tracked stuff, I'm not sure putting your primary sources of locomotion on the relatively stickie-outtie top rear corners of the hull is a smart move. You could bury them deeper, but that'll cost you at least some of your hard won protected volume. Either way, I think there's a case to be made for copper or aluminium wires for drive trains. Not necessarily engine related, but: having a huge generator on board opens up win

Regarding rafts of engine concepts, a vehicle with electric motors and an empty engine bay could offer a myriad of possibilities. Just add electricity. Xoon mentioned free piston linear generators. A few of these, and whatever you want to feed them in the tank, and you can go do your thing. Additionally, if the vehicle were to take a hit, as long as some FPLGs remain operational, you do too (I think). A group of students from Eindhoven built a formic acid fuelled range extender trolley to hang behind an electric city bus. If the contents of the trolley could be made to