ok, lets skip the physics debate, shall we? Actually in most Sci-Fi (except maybe Star Trek) the engine and reactor core are directly related to each other (often one and the same or directly connected), so a bigger engine wouldn't even work with a fighter reactor core. And if you put enough junk on a fighter to let it operate with a capital ship engine, then all you have is a seriously outgunned capship. But I've lost where this discussion was supposed to go, so I'll leave it at that.
Oh yeah, back on the original topic:
Those Terran glows really do look cool, but FT, be careful. When you make the actual glow small in comparison to the image file that contains it, you tend to get a lot of clipping from the side views, as you stretch the image farther in an attempt to offset the small glow size. The resulting glow then spills outside of the ships hull and looks really bad. But it does look good so far.
