Originally Posted by
Zog
The time circuits weren't nuclear. That baby was electric! They just needed the nuclear reaction to create the 1.21 gigawatts to power the time circuits. Just the engine for the car took gas. I can't figure out why Doc didn't replace the gas engine with Ford's crate electric motor from the Mach E when he was replacing the nuclear reactor with the Mr. Fusion and doing the hover conversion. Also, how did the gas engine power the car after the hover conversion. Further, wouldn't it have been wise to have put the car in hover mode as they approached the bridge in the 3rd movie? Lastly, if Doc Brown could build a nuclear reactor small enough to fit in the DeLorean motor compartment, why wouldn't he commercialize it in 1985. He could have been rich beyond belief!