"Everyman's Jet Engine" - Why Valveless Pulsejets? Reasonable thrust/weight ratio For engines actually intended for propulsion, thrust-to-weight ratio is an important specification. With lightweight stainless steel construction and good overall design, it is possible to obtain T/W ratios of 4:1 or a little better. With the addition of well-designed thrust augmentation, even higher ratios should be possible. This is not as good a figure as you can get with a model turbojet, but a turbo will cost you at least ten times as much for the same usable thrust. It is certainly better than any currently used piston engine design, at least when used as an aircraft powerplant.