Experimenter

August 2013

Experimenter is a magazine created by EAA for people who build airplanes. We will report on amateur-built aircraft as well as ultralights and other light aircraft.

Issue link: http://experimenter.epubxp.com/i/149316

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so many wires and sensors, more than a hundred in the system, that I needed a better method. Searching through hot rod and racing magazines, I finally found a simple digital system. This computer system controls both the ignition timing and fuel injection system. It also has an onboard computer that lets you adjust timing and fuel flow at will. This makes it easy to adjust the fuel/air ratio when at altitude. "I maintained the original fuel injectors and installed six fuel pumps. Since the airplane has four fuel tanks, I use two low-pressure pumps to transfer fuel from auxiliary tanks to main tanks, two to supply a small header tank, and two high-pressure pumps to supply the injectors. This is all done for redundancy." There are lots of ideas worth borrowing from Victor's airplane, but one that many may find useful is the way in which he balanced his headers for power. To determine the exact length of each tube and keep them equal, he filled one with peas and then kept trimming the rest until they held the same number of peas. This could well be a trick left over from his motorcycle racing days. Victor believes in keeping track of things, and the console between the seats displays factors from fuel level in each of four tanks to whether the cowling is latched and everything in between.  The 2-¼-inch primary tubes flow into collectors that dump into distinctive 6-inch-diameter augmenter tubes that, besides guiding the exhaust well back under the fuselage, help suck cooling air through the cowling and radiators. They also sound really cool! Victor said that one of the hardest things when doing something no one has done before is designing to ensure that everything is accessible and is easily removed so it can be checked. He said, "It took three months just to design the engine mount. That was done by lying on my back and looking up at every possible obstacle I could imagine." Not liking the idea of the bushings in the electric IVO prop mechanism always being in contact, Victor devised a way to allow them to contact only when changing prop pitch.  When it was time to fly the airplane, Victor elected to do his own first hop, which while it went fairly smoothly, wasn't without incident. "I found out quickly that the plane was wing heavy and the aileron trim wasn't strong enough to keep the wing up if one auxiliary tank was full and the other empty. Also, on the first landing, the fiberglass gear legs weren't strong enough and one started to collapse. It caused minor damage, but it was obvious that the legs needed modifying; so I had Robbie Grove [of Grove Tailwheels] make up some aluminum ones, which work perfectly." Victor is the first to admit that when you build something as complex as an airplane, especially when you're pretty Photography by Budd Davisson One of many micro switches feeding the display in Victor's cockpit; this one monitors the cowling latches.  EAA Experimenter 25

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