If Doc Brown had gone to the future and bumped into Tony Stark, and instead of the Mr Fusion home reactor, Tony gave him an Arc reactor to fit to the Delorean, would it have been a viable replacement to generate 1.21GW to travel through time? How long could is be used for if so?

Scenario 1) The original Arc Reactor that Tony built in the cave, that couldn’t power his armour effectively (this had an output of 3 Gigajoules per second I think)

Scenario 2) the Mark II he builds to power the Iron Man armour, no numbers were provided for the power requirements/output, other than it must be more than 3GJs

Unless I’m wrong, the “new element” reactor should have been able to power the Flux Capacitor, as it powers a “Petawatt Laser” in the Mark VII suit for at least 3-4 seconds.

We’ve never been given the exact inner working of the Delorean Time Machine, so for argument’s sake, let’s say the 1.21GW needs to be sustained long enough for the car to travel, front to back, through a portal at 88 miles an hour, the car has a length of 4,267 mm (168.0 in), not accounting for the Time Machine components at the front and back