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/471466
12 Vol.4 No.3 / March 2015 BILL AND K YOUNG CL APP'S CORVAIR-TAILWIND THERE HAS TO BE A MEMORABLE name for Bill and Kyoung Clapp's Corvair-powered Tailwind. How about Corwind or Tailvair? It doesn't make any dif erence what you call it; the Clapps' Corvair-Tailwind that they brought to EAA AirVenture Osh- kosh 2014 was the latest application of an engine that was designed to push its driver but now pulls him around at much higher speeds. Although the movement to use the Corvair automotive engine in aircraft has been slow to gain traction, there are now a number of companies, Bill's Azalea Aviation ( www.AzaleaAviation.com ) among them, producing infor- mation and parts for Corvair engines that are beginning to make big-time inroads in homebuilt aviation. Google "Corvair Aircraft Engine" and several companies will pop up. FIRST, THE ENGINE For those who don't remember the Chevy Corvair, it was a semi-sports/compact car for the masses produced from 1959 through 1969 (model years 1960 to 1969) that was powered by an air-cooled, six-cylinder fl at engine that looked as if it was specifi cally designed for use in airplanes. It has an aluminum crankcase, iron cylinders, and aluminum heads and was built in three basic sizes—140 cubic inch displacement (CID 2.3 liters), 145 CID (2.4 liters), and 164 CID (2.7 liters) putting out 80 to 180 hp. Now, however, aftermarket stuf such as crankshafts are pushing displacements up to as high as 183 CID (3 liters). The early production crankshafts were cast iron, but Chevy switched over to forged cranks in 1965. In aircraft, these engines are swinging a prop via direct drive (no reduction unit) and putting out 100 to 120 hp. They weigh about 225 pounds in fl ying condition (a Continental O-200 weighs about 200 pounds dry). Roughly 2 million Cor- vairs were built, but the later models are more desirable. Bill said they can still be found in scrapyards for relatively low dol- lars. That's one of many reasons parts are easy to come by and why there is such a strong aftermarket parts support system for it within the automotive enthusiast markets. Bill said he has something like 30 Corvair engines stashed around his work- shop. Apparently the accepted proverb says a man can never have too many Corvair engines. Bill, who bases his business in Valdosta, Georgia, was literally born into aviation. His dad was a pilot for Mission Aviation Fellowship (MAF) for many years. Bill said, "When we returned from the mission fi eld, he got a job as a mechanic and supervisor for Northwest Airlines. When I was a year old, we had moved to Mexico where Dad fi rst started fl ying for MAF. From then until 1982, we had airplanes literally out our kitchen door. Dad primarily fl ew C-180s and C-185s. Most of this was in hostile jungle environments in Mexico, Colombia, Ecuador, and Honduras. "In the early 1970s, my parents visited Ken Rand in California, and my dad had a KR-2 kit shipped to the jungles of Ecuador where he began building one of the fi rst experi- mental aircraft in South America. I remember spending many hours with my dad gluing blocks and sanding foam. "The airplane made its maiden flight on Thanksgiv- ing Day, 1981. It was one of the most inspiring things I can remember…seeing a dream turn into hard, honest work and develop into reality." That concept of building an airplane from nothing had far- reaching ef ects on Bill, and later, on his wife, Kyoung. They met when she was getting a degree in accounting in Valdosta, and she is very much a part of his entrepreneurial aviation adventures. She said, "I took ground school and have about 10 hours of dual in a C172SP. We thought is was important that I get the feel for fl ying and understand how airplanes work and why. It helps me in the business to understand the pieces and parts and will make me a better business partner with Bill. Also, since we fl y together a lot, I can be useful in navigation and watching for traf c." Bill's fi rst airplane was his dad's KR-2, but in 2003, when he decided to scratchbuild his own, a KR-2S, he stepped into the world of the Corvair engine. Photography by Michael Kelly Clapp leaves no doubt about his engine's fi ring order or ignition timing. Close-fi tting fi berglass plenums ensure that the Corvair's cylinders get maximum cooling.