The BD-5's cooling problem is no different than what any other rear-engine aircraft faces. I've daydreamed about two possible solutions; one would be a Meredith-effect belly scoop, and the other would be to use the aluminum fuse itself as a heatsink by running coolant lines along the interior of the engine compartment. I had a conversation a while back with an aerospace engineering professor who told me about a couple of aircraft that ran coolant lines up through the wings - obviously that's going to be tougher for a plane with removable wings. Regarding the driveline, obviously that problem's been solved by a number of people. It seems like in this day and age someone should be kind enough to disseminate the solution in the form of PDF drawings or scans of the two or three drivelines that have been proven to work. Someone??? Kent, if you'll scan those blueprints, I'd be willing to put the time in to turn them into SolidWorks mechanical drawings and subsequently into PDFs. EDIT: Kent, just noticed you have a Cozy, a Long-EZ, and a BD-5. I can see how the progression might have taken place.