Just the other day we reminded you of a diesel motorcycle currently being built for military purposes, and before that we shared information on the Neander Motors' machine with its dual counter-rotating crankshafts. These products prove that there is significant interest in diesel motorcycles, a fact not lost on the Gray Eagles, an "informal collection of retired engineers and executives from Harley-Davidson and Outboard Marine." These engineers are working on converting the V-Twin engine powering numerous Harley-Davidson motorcycles to run on diesel and/or biodiesel fuel. Along they way, they've added fuel injection and a turbocharger for good measure. If produced, the Harley-diesel could do 100 miles per hour and return 80 miles per gallon. Potential customers for this proposed vehicle include Harley-Davidson themselves as well as the military ... oh yeah, and this writer.