Corvair House Call, Range: 335 miles.


Over the years I have done something several hundred times that other aviation businesses don’t: I made a house call. Our primary work is educational, and the hardware sales support that mission. This difference has many ramifications, but one of them is that we take the time to meet builders whenever there is an opportunity to advance an individual’s knowledge and project.

Last week I was headed to Columbia, S.C., to help my sister move. Technically this wasn’t a true house call because I only made it 335 out of the 400 miles to York, S.C., where builders Michael Durbin and Stefan N-Plotnicki are getting started on their Zenith 650 kit. I spoke with them on the phone and Michael suggested that they would be glad to load up their Corvair on a stand in the back of Stefan’s pick up and meet me at my sister’s place for an evening “house call.” This offer of meeting me part way and their enthusiasm for their project set the tone for a productive visit.


Above photo taken in my sister’s driveway. Note Corvair on stand in the back of the truck. Stefan on the left and Michael on the right are brothers-in-law and partners in a Corvair powered Zenith 650 project. Their wives are sisters. Michael has long been involved in aviation and served as a mechanic in the USAF.  Stefan has a lot of mechanical experience on different engines. He is a proud native of Poland. “Na zdrowie!”


Michael and Stefan purchased their project from the family of a builder who was sadly killed in an auto accident. The builder had done some work on the engine to clean it up and put it on a stand, but had done no work to the airframe kit. Initially the original builder was thinking of putting the Corvair on a plans built wooden kit, but later opted to purchase the 650 kit. These guys suspected that the engine they have is basically a good core, and my inspection proved them correct. The view above shows that the engine was very clean, but was not actually rebuilt. The rod bolts in the picture are used stock ones and the piston skirts show that the pistons are cast. Many years ago I had a difficult time convincing some builders to put quality parts in their engines. Very rarely do we see stuff like this any more. Michael and Stefan plan on a first class rebuild and are only planning on using this engine as a very clean core.


The above photo shows that the pistons are not just cast, but they were also used. Some builders who had been in the EAA a long time had heard that Pietenpol builders in the 1970s had flown Corvairs directly removed from cars with some success. This is true, but I have never encouraged people to do this. We ask much more output from engines now, and for reasons outlined in my Manual, I would actually trust a 25,000 mile stock car engine over the above engine. Re-torquing original rod bolts and using thicker base gaskets on an engine with previously rigid cylinders would actually make the above engine less reliable than one just pulled from a running car. Either way, the point is academic, because no one is planning on flying either of those concepts today.


Above: Home-made  4″ deep sump pan fabricated by original guy. The rough areas are partially ground down welds. The cut outs in the pan lip for the mounts would leak like a sieve. This builder was not following mine nor Bernard Pietenpol’s notes. Both of us told people not to cut the pan like that. Ideas like the one above show that the original builder was willing to put in time, but was not willing to follow known information. The original builder actually had one of our Conversion Manuals. Ideas like this were once common on the Internet, promoted by people who had never built a Corvair themselves.


Above, the project is now in the hands of two very positive builders who are aiming for an outstanding aircraft and engine within a reasonable budget. Their previous mechanical and aircraft experience guides them to a much better quality and far more proven path than the first builder was charting. The above photo was taken after we got to spend two hours going over details and fine tuning a build plan that was tailored to their budget and timeline, and also meets their personal goals of becoming experts on their own engine. In their hands are a number of the parts that they picked up from me that evening. Michael is also holding his Zenith 650 plans set. He brought it to ask me if the Corvair required any airframe changes or alterations to the Zenith fuel system. I pointed out that one of our original design goals with our first Zenith 10 years ago was to make no changes behind the firewall whatsoever. If a picture is worth a thousand words, this one says that much about their positive attitude. Look for these two to have an engine running at a College by the end of the year, and a flying plane next season. Good goals, but just physical manifestations of the real achievement, becoming a proven aviation craftsman and an expert in both your airframe and powerplant. -ww

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