2,850cc Corvair for Zenith 650, James Siebenaler.


The fourth engine to run at our joint FlyCorvair/SPA Panther workshop/Open house was built by Jim Siebenaler for his Zenith 650. He had just relocated from Ohio to the Florida panhandle a few weeks before, including buying a new home and moving the project, in addition to family stuff, but Jim made the choice to take advantage of the event, and not put off a chance for progress and good times. The reward for this decision is evident in the photos.



Above, Jim’s 2,850cc Corvair running on the stand. It started instantly and layed down a perfect break in run, the only adjustment we made was to tighten one oil line fitting 1/16 of a turn. Not bad for a motor which was built in its entirety in 2 modest days work at the event. This was possible because Jim did his homework before arriving, he coordinated with SPA to make sure he had every part, he followed the new SPA Assembly Manual step by step, and he wrenched in a relaxed but steady pace over the two days.



Above, Dan and Jim check out the motor as it runs. This is typical of the more relaxed setting we have at events like the Workshop and the Finishing Schools we have run at the SPA/Panther factory. We will always have Corvair Colleges, and I love them, but some people like a slower pace and a smaller setting, and the workshop served this. It is the middle ground between a full on Corvair College and scheduling a personal build and run at my hangar.



Jim worked with us for nearly a decade, yet this was the first event he was able to attend. There is good reason for this, He spent more than three decades in service to our country, and has only recently retired. He has logged more than 3,400 hours in rotary wing aircraft, including flying the latest models of CH-47 Chinook in war torn parts of the world. It was service and family first, but he carefully planned and made progress where he could. The test run was a tribute to his strategy of persistence. To understand how this vital element is embedded in every aspect of our work, look at this story:  The Vindication of Persistence.


If you look at the photo, you will notice the motor has the most up to date 2400L starter on it. It also has a SPA billet crank in it and many other options which came along in the last decade. Jim didn’t restrict himself to building a 2008 motor because that ways the year he got started with a manual and a core. He wisely chose to take advantage of all the things we have learned and updated. There is noting wrong with motors as we assembled them in 2008, and there are plenty of them in service flying every week, but Jim made the chose to have a fully up to date motor, and take advantage of all the information we can share with him.



Above, Jim gives his take on the “Captain Morgan Pose”. That smile is provided by having the accomplishment and satisfaction of a perfect break in run of a motor built with his own hands, an engine he now understands very well. A day will arrive when this plane takes to the air later in the year. It will arrive because Jim didn’t blow off opportunities to learn, make progress, and have a good time. When you read about upcoming events, keep in mind they are all opportunities to advance your own project, to make sure that you also will have a day where your own aircraft takes to the sky. The only thing this requires is your personal decision you will not keep putting off your own goals for a ‘some day’ which will never come.




About William Wynne
I have been continuously building, testing and flying Corvair engines since 1989. Information, parts and components that we developed and tested are now flying on several hundred Corvair powered aircraft. I earned a Bachelor of Science in Professional Aeronautics and an A&P license from Embry-Riddle Aeronautical University, and have a proven 20 year track record of effectively teaching homebuilders how to create and fly their own Corvair powered planes. Much of this is chronicled at www.FlyCorvair.com and in more than 50 magazine articles.

3 Responses to 2,850cc Corvair for Zenith 650, James Siebenaler.

  1. Larry Elrod says:

    I know the feeling.

  2. Brandon Scott Edmonds says:

    Is the 2850 piston and cylinder kit still available? I have not been able to locate the listing for it. It is entirely possible that i have overlooked it or not been looking in the right place.

    • Brandon, it was superseded by the 2,775cc kit which has all the same features, with a little less displacement but readily available cylinders which weigh about 5 pounds less per set.

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