Bob Dewenter’s Pietenpol project


Bob Dewenter, aka “Early Builder”, is one of the most illustrious characters in the land of Pietenpols. Bobs plane combines a standard wood fuselage with straight axle gear, aluminum wing spars and a modern Corvair installation. How did Bob get this far? One day he decided to buy a manual, and go get a core motor. If you will one day have a project this far in your hangar is dependent solely upon this: Will you make today the day you get started, or will you eternally put it off until tomorrow? Your life, your choice. Be happy with your decision, Bob is. -ww.


From Bob: “Pietenpol Update”

Hello good Corvair people.  Greetings from Golden Valley North Dakota and Dayton Ohio.  William asked me to spend a few minutes and provide an update on my Corvair powered Pietenpol Project which I started by attending Corvair College 19 in Barnwell.


My main focus this past building season has been the wings.  One is 95% complete sans aileron hardware, the second is about 20% assembled.  Anyone who has built a house knows the framing makes it look like a house but you have a long way to go before moving in!  My good friend and Zenith 750 STOL and Corvair builder Terry Lambert has offered me a huge table in his hangar for laying out the wings and having access to his tools is very much appreciated.  Having a Hangar pal keeps you really motivated to make progress!  Terry has also taught me a lot about working with aluminum – he’s retired now but worked on a lot of Air Force aircraft.  And speaking of motivation, I’m trying to keep one step ahead of my friend, Corvair Piet builder, Terry Hand (“Hello Mr. Hand” re: “Fast Times at Ridgemont High”)



Terry Hand, William and I discussed the merits of aluminum spars and I am really happy with this choice.  Being in the heart of Air Force country, My EAA Chapter is full of accomplished builders – mostly Zeniths and Vans and they all LOVE the wood ribs!


The fuselage and the rest of the plane are in my garage at home so I can make some progress any day I am home which is normally 5 nights a week if I’m not traveling on business or getting distracted with life’s little nuances.  I have been “test fitting” the oil cooler and engine baffling.  I need to re-do the baffling around the oil cooler – my prototype was not right.  Dan’s baffling kit is beginning to look better!  But I have a great sheet metal coach in Terry Lambert and would like to give it another try before throwing in the towel.



Where possible I have chosen to use all Williams’s parts (and soon Dan’s) because they are proven, they are reliable and it’s just “Plane” faster.  I have all of William Gold Parts – gold prop hub, gold oil system, gold oil pan and his non-gold parts such as safety shaft, hybrid studs, starter kit with ring gear, SS intake, SS exhaust, and a strong reliable engine mount welded by Vern.   I rely on professional like D&G for my carb and Moldex for crankshaft work.



My motivation at this time is to complete both wings as this will complete the build of all the “large objects that attach to the plane” and then to get the motor ready to run again. So I will need to get the fuel tank cleaned, test it for leaks, mounted and plumbed to the beautiful D&G rebuilt MA-3SPA carb.  I have to plum the oil cooler to the gold sandwich adapter.  Oh and finish the baffling and make a temporary cowl like the test stand has.



Things I took a LONG time to decide on are now moving forward.  I decided on a center section fuel tank.  I fabricated the tank last fall and had a retired (i.e. low cost) A&P IA weld it up for me.  It should hold a little over 13 gallons. Note the Don Harper fuel filler neck and cap, Thanks Don! See you in November in Barnwell! And I decided to order a Gold front alternator bracket mount from WW – was not sure where I wanted the alternator until I started looking hard at the firewall.


I have not set any records for build speed but I don’t care.  I have TRULY enjoyed every bit of time spent so far and look forward to every hour I will continue to spend on the project.  It is in my heart.  One day I will be flying over the corn fields I drive through today.  I will get to pull up aside a locomotive engine pulling a long line of freight and wave to the conductor.  I will see and smell the earth from a new perspective.  And of course I can’t wait for the first Pietenpol flown weasel roundup!


Everything I have done on this plane using my own two hands has been extremely rewarding.  Sometimes after a part is done I will just sit and stare at the creation I have made.  My son Tim is now about to turn 8 – roughly the same age as my project.  Tim coming into my life was the catalyst that actually got me started on this project at Corvair College 19 in Barnwell.  Introducing my son to Building an Airplane has been fantastic as well. I have a “MEME” of a beautiful J-3 flying at sunset with the phrase “Teach your kid to fly and they will never have money for drugs!”


I’m fortunate and grateful to be able to spend my weekends on a boat on a lake with my family, to be able to work hard at my profession, and to have a wonderful family with Tim by my side working with me on my Pietenpol project.



Above Gratuitous “Tim-e” Photo


*ww note: Sharp eyes can tell that Bob has not yet installed his Gen I Weseman 5th bearing, but he is going to because: Yes, Pietenpols do need 5th Bearings..


The Next Event on the Schedule:

FlyCorvair/SPA – Joint Workshop/Open house, May 18,19,20

Also get a look at:

Build a 3.3L Corvair at the May 18-20 Workshop/Open house.

Read the links now and make a plan today.


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 and in more than 50 magazine articles.

9 Responses to Bob Dewenter’s Pietenpol project

  1. Jim Tomaszewski says:

    Looks great Bob! I remember you from Barnwell a few years ago when I ran both of my engines. You were a huge help and very nice guy! My twin engine is done and just waiting for the FAA inspection.


  2. Dan -o says:

    Looking good Bob, I’m starting to get excited now as I’m real close to getting my airworthiness inspection, going to Buzz Aviation the first part of May for 5 hours transitional training in the 750, short flight to Dayton by fall I hope

    • Bob Early Builder Dewenter says:

      I would like to meet up some time and take a look at your Piet…Tell Albert I said hello.

    • tim hansen says:

      Dan, can you give a review of your experience with Buzz Aviation after you go in May? Transition training is important to all of us, and a recommendation for or against them (or other training options), and other thoughts would be helpful. Thanks.

      Also – Looking good Bob, keep up the good work. Barnwell beckons…

  3. Terry Hand says:

    Nicely done, Mr. Dewenter. Your work looks great, and I am anxious for the day when we both make the flight up to Brodhead together.

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