Using the Create CV Curve Tool, I made a sort of J shaped curve around the bottom of the engine in the side view, and then altered it slightly to make it more curved at the bottom using the Control Vertex. Back in the perspective view, I then altered the curve again using the CV's but in a 3D space, so the curve started at the edge and ended underneath the engine.
In order to create geometry around that curve, I had to create a circle NURB and shift select the curve and extruded it. This gave a tube like geometry around my curve, but it wasn't thick enough, so I increased the radius to make the tube thicker and more pipe like. I then altered the pipe slightly by moving the CVs around again as I tried to get a shape I was happy with.
In order to create more pipes along the engine, I grabbed the curve I had originally created and duplicated it twice, attached them both to the NURBS curve and extruded them to create exactly the same shape as original pipe. I then grouped all three pipes together, duplicated them and changed the number in the Scale X option to -1 so it mirrored the pipes, and used the Freeze Transformation so it wouldn't stay in the negative.
I then offset the mirrored pipes so they sit just below the originals by moving the CVs around, and the pipes are done.