Hi Arthur, hope you don?t mind but the only areo? engineer that I know and I want to pick your brains, so to speak. I have a dream to build an aircraft with a difference and in doing so, bend the rules slightly. As I usually fly alone, I hanker for a warbird replica and have long had a ?love affair? with the Westland Wyvern S4. http://picasaweb.google.com/dg.mansfield/WestlandWyvernS4/photo?authkey=aKFdUoqGyS0#5218240547659938002 As you can see, it?s a contra rotating prop setup and although it goes against the single engine, single prop rule of RAA.Aus, I want to do some experimental work to see if my ideas work, prior to approaching the rule makers, and CASA if necessary, to allow me dispensation to fly my dream. The Power Plant: (1off) What I envisage is 2 VW (or similar if cheap enough) blocks mounted one above the other and offset, facing in opposite directions so that their starter ring gears intermesh. Fuel will be fed via a common carbie system with single throttle and carbie heat controls, fired by a single distributor modified to 8 cylinders, and exhausted via a common collector box, then out through twin mufflers below the cockpit as per the real thing. The Propulsion System: (1 off) 2 direct drive shafts with suitable support bearings and flexi couplings are taken from the front of one block and the rear of the other. A belt drive with a 1:1 ratio couple the shafts to a concentric configuration on which the props are fixed. Sounds simple but I realize there are many potential pitfalls. Heat at the ring gears and prop shaft bearings lubrication being the most obvious. Ignition timing will also need some form of variable setup so that the two blocks work without vibration between each other. I think a variance of flywheel rotational position might sort that out. Taking weight out of the equation for now, what do you think? Will it work? Is there some great factor I have not seen? Looking forward to your reply, Cheers, Doug (Deskpilot) Mansfield.
