It’s for an animation so the thrust needs to be animated. It doesn’t have to alternate in intensity like in that video (although that would be nice) I just want to be able to do something more than add an emission shader to the engines.
That video looks like a few cylinders painted with emission/alpha maps to look like flames, then animated to stretch and bounce using a shape key or something. You could also sculpt out a flame and give it volume emission. Might render slower, but will have more structure to it.