the thermo engine is a curious design, the dead spot where the motor is that hampers performance on most fans shouldn't have that much effect on the thermo, I can't think of a way in which you would attach it using a grill like some people do on most heatsinks, I would surgest that you make you own shroud for it out of a biscuit tin, first start of using card and make something similar to the standard shroud but obviously to fit an 80mm fan, shape it kind of like an upside down piramid, then when you have finalised the design use it as a templet on a flat peice of thin metal (biscuit tins are great for this as they are easy to cut with metal cutting scissors) and cut it out and fold it into shape, I made my own for my FOP 80, as soon as I get my capture card I'm going to write an article on it.