Adding Detail Engine - Part III

I've been trying different designs for the rear section of the engine. In my original sketch I imagined a bunch of small metal tanks that could be filled with some gas, but I think I could add some variation on that area. I tried out having four, and two tank configurations. The main idea behind the two tank configuration was to have more flexibility with the shape of the engine cover that will go on it. I've done some paint overs and concepts, but I'm still not 100% happy with the shape of the engine in the back, but this is what I have so far. I keep finding that some of the designs that work in 2D sketch don't really translate as smoothly to 3D and don't provide the shapes or flow that I need. Some of them also look really boring or uninteresting from the cockpit view (assuming this ship would ever be used in some sort of racing game or 1st person scenario.)