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  • DavzLSA progress

    HI Guys,
    I have progress to report, I got my corvair engine running. Around the middle of November I loaded up my assembled engine and my son and I took it down to Florida to the Flycorvair finishing school and ren the engine. It ran perfectly. Now I have my fuse tacked together just today. I would have kept welding but I ran out of acetylene gas. The tubing kit I got from Mark really made short work of getting the fuse together. Hope you all like the pics. Oh please dont be too hard on me about the welding, its not finished and only a tack weld.

  • #2
    Looks great!

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    • #3
      Lookin good! I can't wait to see how that engine does. Always intrigued me.
      Scratch Built 4-place Bearhawk. Continental IO-360, 88” C203 McCauley prop.

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      • #4
        Awesome progress! Great technique using the dado notched 4x4 blocks. Wish I had thought of that when I was at that stage. Keep us posted on your progress.
        Stephen B. Murphey
        Bearhawk LSA
        Building #L-089

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        • #5
          Hi Guys,
          Some progress to report. I now have my vertical stab attached to the fuselage. Today I finished my 1st horizontal stabilizer. I bought the ribs from Mark. I bent the leading edges for the horizontal and the bows for the elevators all at one time. Its was the part I hated the most because I was afraid id screw up some good metal, as it was I think I did OK. Before I began I lofted the horizontal stab curves and elevator curves on 1 inch graph paper from the plans to make the curve templates. Got nice curves and didn't kink any tubes. I have some photos, Its the bending jig I made and my midget torch. If you are welding the hard way with gas like I m this torch is a life saver and it greatly improved my welding. I'm not fighting the weight of a regular torch and that gigantic heavy hose. I still have a ton of welding to do.

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          • #6
            Looks like some mighty fine work!

            Bill

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            • davzLSA
              davzLSA commented
              Editing a comment
              Hey Bill check this link out, it a good example of how good the corvair engine is. https://flycorvair.net/

          • #7
            I like the torch and I also found the lightweight hoses were great..

            Don't know if you have one, but I used a "Gassaver" like this (https://www.amazon.com/Smith-Solderi.../dp/B001ASA01U) I purchased off Ebay for about $65

            For about a year, it seemed like I basically lit it when I went into the garage and shut it off when I was done.

            And then suddenly, the welding is done and it all is set aside.

            One thing that worked for me was to make the tab that holds the elevator pivot bearings a press fit on the cross tube in the rear stabilizer mount then weld the mount in. Once the stabilizers are mounted, I found it useful to be able to adjust the tab after the elevators are test fit to the horizontal stab . A small rotation of the tab changes the amount of deflection available on the elevators. Once things were to my liking, I removed the elevator and bearings and welded the tab to the cross tube.

            The elevator horns need to pretty closely match the plans outline to be able to get them worked up in place and over the pivot bearings.

            Once everything is in place, there isn't a ton of clearance between the trim horn(s) and the elevator push/pull tube so you will need to play with it a bit to optimize clearances.
            Last edited by BTAZ; 04-10-2017, 12:25 PM.

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            • davzLSA
              davzLSA commented
              Editing a comment
              BTAZ go you have any pictures of the elevator horn before you welded it together?

          • #8
            Hi BTAZ, Ive been looking at that too and it was my intention to get it all aligned before welding it in place. I think I will align the elevators and horizontal stabs all at one time that way the horizontal stabs and elevator will have the correct incidence angle. Looking at the elevator horn I have not yet figured out how to get that little kink like the plans show. I wish there were more views of the drawing. or some more detailed pictures. Thanks for the compliment Bill.

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            • BTAZ
              BTAZ commented
              Editing a comment
              I think I remember a bit more of how I formed the joggle.

              After I had the pieces made, I clamped them together and match drilled the lower two holes. I put bolts through these holes and then pried apart the ears at the top. Then I put an appropriate thickness spacer between the two ears and squeezed them back together. That put in the joggle and then I welded on the doublers. Bolted them back together and match drilled the push rod attach hole through the ears.
              Last edited by BTAZ; 04-11-2017, 08:21 PM.

          • #9
            IIRC, I thought about how to "gracefully" put in the joggle and then just "did it" in my vice with padded jaws..

            I think one could also use some "offset jaws" to put in the joggle.

            I don't think I have any more detailed photos of that area or how I approached it then what is in my build log
            https://www.dropbox.com/s/p9v1iettu4...elage.pdf?dl=0.

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            • #10
              The corvair engine intrigues me! What RPM will it be turning at rated power? Will it have dual spark plugs? What type of ignition? Engine weight? Single carb, dual carb or injection? I've always liked those engines. Seems like about a perfect match for the LSA.

              Bill

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              • #11
                Thanks for that info BTAZ, ill try that, Bill the corvair engine is very comparable to the continental o200 is physical size and weight. I have the 3000cc engine and it is dynoed at 120 hp at about 3k rpm. It has a regular auto ignition with 2 coils and 1 distributor. but it is dual points one a mechanical point and the other an electronic point. It uses a 67 inch warp drive prop, it uses a ma3spa carb, If you are interested I highly recommend you go to William Wynnes web site flycorvair.com, My engine is basically a kit engine, it has a 5th bearing where the prop hub attaches, it uses a high volume oil pump and a t10 cam.it uses single spark plugs per cylinder. Its a very smooth running engine and will produce a large percentage of full power on 5 cylinders. It has forged pistons and rods. Its a very tough engine. The thing I like most about it is its simplicity and the fact that I can get most part for it at the local auto parts store. For the price of a run out core o200 you can build a new engine with all new parts. That's the way I justified it. And the fact that there are hundreds of planes flying the engine with hundreds of hours. I have video of the engine running on the test stand but I dont think I can post video here.

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                • #12
                  All good stuff, Dave! I've been a pilot for over 40 years, but a gearhead, looking for more power, longer than that! Always thought Ralph Nader was a nut. Dual points, I understand. Not sure how you do 2 coils with 1 distributor, though. The Warp Drive prop is a great one. I bought a Kitfox amphib, with a wood prop. The spray was devastating to that wood prop. The Warp Drive guys said their prop could live CONTINUOUSLY in the water spray, with no ill effects. They were right. Great prop!
                  Please keep us up to date on your progress.

                  Bill

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                  • #13
                    Hi BTAZ I reviewed your PDF file again and found that you did a great job in documenting the elevator horns and it has pretty much answered my questions. Your PDF file is invaluable for us scratch builders. Thanks

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                    • #14
                      Hi Bill, the 2 coils are wired to the 2 sets of points, the output of the coils go through a passive coil switch. So which ever set of points you have voltage switched to is the one that fires its coil.

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                      • #15
                        oh something else about the corvair bill, the carb flanges are milled off the heads and aluminum intake pipes are welded on the intake logs, it then uses a y shaped intake manifold made of welded stainless steel that puts the carb under the engine like a continental. The engine has to use carb heat as well because the intake manifold gets very cold. Like any normally aspirated flight engine.

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                        • Bdflies
                          Bdflies commented
                          Editing a comment
                          I noticed the welded intake pipes. Is that done to reduce height?

                          Bill
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