Considering a Corvair

[dc75]

I'm also considering a sonex with a corvair, has any installed it with an aerocab from sonex? I read some where it would fly 150 mph at 5.5 gph and 170 mph at 7gph, are those numbers with a carburetor or with a tbi like rotec o aerocab? With wheel fairings?

I fly my 3.0 with an aeroinjector. I am still in test phase, but I get 145 IAS at about 6.0 GPH. I have had no issues with it at all. I set it up rich, and lean aggressively on the ground.

[Speed]

Grindio: I have a straight tail dragger with a Clapp Spyder Covair 100HP (2.8L) running a Sensenich wood 54x52 prop with pants/ leg fairings. I bought it set up this way. Your question is a bit loosey goosey since you don't specify Indicated vs True or Altiude.
Mine runs an easy 145 mph IAS at 2,500 MSL at about 3,500 rpm. But I like to cruise between 5 to 8k feet. At 7,500' she'll true about 165 MPH at 3600 rpm (WOT) and about 150 MPH True at 3200 RPM. Strong, smooth motor. Love the Clapp setup. Over 300 hours on it. With AeroCarb. In process in investigating new props. Friend broke my sensenich (cracked tip off just beyond repair limit). I believe I want a bit more bite in the prop for better cruise. Maybe a Prince P-Tip 54x54. Don't know yet. Have a borrowed sensenich 54x54 that I have not had a chance to fly yet. Plus, I intend to do some aero cleanup, including vortex generators. And move my CG back a bit with a little ballast in tail. Hoping to get an easy 170MPH true at a little less RPM She's quite happy at 3600 all day, with CHT's below 350. Plus I have the wing tanks so at 6 GPH I should be able to fly to bladder limit! I never add oil. Plugs stay clean. It runs COOL and sounds COOL! I recommend you give Bill Clapp a call. I'm curious to hear more from DC75.

[vigilant104]

Speed,
What is the empty weight of your plane with the Corvair engine and those aux tanks?
Bill Clapp is a very approachable guy, and seems like a straight shooter without an "attitude." I have heard from several folks who have purchased his products and been very satisfied with them and with his support. Yours is the first Sonex I've heard was fitted with his engine, I'm glad it is working well for you.

[daleandee]

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[Speed]

vigilant 104: Good question, it weighs 770. Thats' With a 680 battery behind the seat. And the cruise numbers I quoted before (at altitude) were all between 1100 and 1200 GW> Obviously Faster when lighter. I've flown it up to 1250 GW with no real issues. But plan to stay below 1200 as a rule. With full fuel and just me it's 1150. Add some baggage and I'm still under 1200...giving a solid 3 hour + cruise with lots of reserve. Just right! With myself and my son (we're both about 180 fully equipped) and 12 gal gas, we're at 1200 and can fly for an hour with an hour reserve (I have the original design aluminum tank with 14.5 gal). With just me and 12 gallons, I'm at 1020 GW...fly her out to open spaces for some light acro and return with plenty of reserve. I do plan to add a little ballast (less than 10lbs) but believe it will be worth it. My first flight in a Sonex was with a larger gentleman in a Jab 2200. After that, I'll tell you that i really like my Corvair! And it looks good with Clapp's cowling, too!
Regarding people: I bought my plane knowing who built the engine. Bill Clapp was very helpful regarding history, capabilities, operations, etc. Small world: I had first met Bill at OSH ('09 maybe?) when he had my exact plane on display with the corvair and wing tanks. I was building a Xenos at the time and loved the idea of the tanks. Still do like them!
BTW: I just attended the Clapp's Spyder Conversion Workshop where we built an engine, learned a lot and had fun. Cost is minimal but return on investment very high! I feel better about owning/maintaining the engine now. Plus I have all his manuals.
Hope this helps! Happy to discuss further. Speed

[Speed]

vigilant104: All that text, and I omitted that the wing tanks hold 5.5 gal usable, each. But i typically only put in 5.0 to avoid venting. that gives me 24.5 gal usable, which is what I mean when I say "full fuel." Essentially, I can actually go places (~400nm) with just me, or take a "FAA standard" pax up for an hour or so.
Speed

[Speed]

Dale,
BTW: prior to my purchase of N77ZZ, reading about you and your plane were a positive inspiration!
PLUS: I'd be very appreciative if you could share your W&B data with me.
I've weighed mine and it's CG is very forward. Have been working ballast options to get CG in mid-range. Curious about your perceptions on the CG issue. Happy to PM.
Many Thanks!
Speed

[daleandee]

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