FlyBaby, BabyAce, Fisher FP303 or something else?

[wanttaja]

Man I just can't figure out how you guys do it at those weights. I weigh 160 and about 300 fpm climb with 16 gallons.

I should weigh mine to see what it really is. I also suspect a rigging issue might be tanking my performance.

Can't remember what engine you have, but I've got a C85. Otherwise, could be a cruise prop.

VSI was removed from my airplane years ago, but I'm guessing I'm seeing ~500 FPM on a 70 degree day. Typically, I can do a touch and go, fly moderately tight crosswind, and be at pattern altitude on downwind at midfield. Better in the non-summer months, of course.

I rarely have full fuel in summer, as I fill from 2.5-gallon cans. Not worth it to add fuel in less increments.

Ron Wanttaja

 

[l8evator]

Corvair crankshafts are not well suited for direct mount props. You would want either a support bearing and a nose housing with a drive spacer mounted on the bell housing flange, or get a billet steel crank made. There are several cases where the end of the crank broke off. They aren't made to take the gyroscopic loads a prop can impress on them.

Folks interested in the Corvair should go to www.FlyCorvair.com and the related www.FlyCorvair.net, both run by William Wynne. I haven't built one of his conversions, but I think he has developed the Corvair into a viable and cost effective engine for a number of homebuilt designs.

Scott

 

[VanDy]

Corvair crankshafts are not well suited for direct mount props. You would want either a support bearing and a nose housing with a drive spacer mounted on the bell housing flange, or get a billet steel crank made. There are several cases where the end of the crank broke off. They aren't made to take the gyroscopic loads a prop can impress on them.

I only know of the guy with the Klenex, having that issue. He was running a shorter prop faster than what would be on a fly baby. My Pietenpol has over 700hrs on it's corvair. And it's an original type Pietenpol conversion with the blower on the top still.

Edit: I do have the factory nitrided crank in it, William Wynn's book has all the numbers in it for which engines are good donors

 

[wanttaja]

Jesse, Ron and others,

What kind of fuel burn are you getting and what, in your opinion, is your sweet spot altitude for performance?

Never have formally measured fuel consumption, but it has to be identical to any other aircraft with a Continental C-85-12. I figure 5 GPH, and haven't run it out of gas yet.

Never have cared about performance at altitude. Jesse has me curious about rate of climb, so I'll probably run some tests. As far as the altitude for best cruise performance....don't know, don't care. Few Fly Baby owners do, other than curiosity. It's not what the plane is meant for...

The previous owner of Jesse's airplane did use the plane for longer trips, one is written up here:

http://www.bowersflybaby.com/stories/matt_trip.html

Ron Wanttaja

 

[wanttaja]

Man I just can't figure out how you guys do it at those weights. I weigh 160 and about 300 fpm climb with 16 gallons

I looked at one of Matt Michaels' write-ups on what he did with the airplane:

1. Increased fuel from 12 gallons to 16 gallons, plus six more in an auxiliary tank.

2. Had the prop twisted to maximize cruise...

http://www.bowersflybaby.com/stories/matt_trip.html

Neither of which would do your rate of climb any good....

Ron Wanttaja

 

[wanttaja]

3. Builder/Maintainer Error. A couple planes lost their wings because the builders used pliers instead of Nicopress swages. Another accident occurred to a newly-purchased Fly Baby that was not properly rigged after re-assembly.

No, not really...wow... That is pushing cheap to new limits.

Kind of indicative of the times, really. I remember, 30 years ago, that our EAA chapter had only one member with a Nicropress swage. "They're over a hunnert bucks!," complained one member.

I've got a 1984 Aircraft Spruce catalog: $124. They're about a hundred bucks more, now.

But these days... a guy who's decided to build an RV will drop $1,000, $1,500 on tools without even blinking.

It's an entirely different environment in the sport....

Ron Wanttaja

 

[ateamer]

When I hear the word "homebuilt", just about the first plane that comes to mind is the Fly Baby. I read Peter Bowers "Guide to Homebuilts" countless times starting at age eight. They've come a long way, but there is no substitute for a simple, classic plane.

 

[Henning]

I only know of the guy with the Klenex, having that issue. He was running a shorter prop faster than what would be on a fly baby. My Pietenpol has over 700hrs on it's corvair. And it's an original type Pietenpol conversion with the blower on the top still.

Edit: I do have the factory nitrided crank in it, William Wynn's book has all the numbers in it for which engines are good donors

The Spyder and Corsa engines had the nitrided cranks IIRC. For the cost of a billet crank these days I can have Crower make me an ultralight, save a bunch of weight, and not have to worry, or if I need the extension anyway I can build a support housing and bearing on the end for even less. All this costs less than going with an O-200 so it is still economically feasible. CAD/CAM and 5 or 7 axis machining cabinets have really revolutionized the 'one off' fabrication shop costs. A lightweight bearing support nose can cost less than $1000 including the extension and flange. Heck, you could do a reduction drive for not a lot more and run the engine at 3200-3600 rpm where it's much happier.

I suppose that on your annual condition inspection you pull the prop and dye-pen the end of the crank and bolt holes to look for cracks right? If you do that every year/100 hrs, if a problem materializes, you should catch it before something comes apart.

 

[bluerooster]

What about a Turbulent, or for a two holer a Turbie? Or mabe a Jodel?

 

[jesse]

I looked at one of Matt Michaels' write-ups on what he did with the airplane:

1. Increased fuel from 12 gallons to 16 gallons, plus six more in an auxiliary tank.

2. Had the prop twisted to maximize cruise...

http://www.bowersflybaby.com/stories/matt_trip.html

Neither of which would do your rate of climb any good....

Ron Wanttaja

Yeah, I never use the aux system though, just don't want to sit in the plane for more than 2.5 hours anyways

The prop could have something to do with it, but open cockpit, 82 KTAS or so is about the max I can get and that's at red line. I also have no issue with getting red line RPM to pretty high altitudes. So I don't think the prop was twisted too much in the cruise direction, but who knows...

That said.. in level flight..one aileron is always deflected. I suspect that was done to fix an issue with a wing being heavy, but I suspect I could fix that issue with just rigging and not have to take on the drag of that aileron. Not sure how much that's hurting me but it certainly can't be helping.

 

[jesse]

Never have formally measured fuel consumption, but it has to be identical to any other aircraft with a Continental C-85-12. I figure 5 GPH, and haven't run it out of gas yet.

I burn 4.3 gph in cruise, consistently. Every time I check that's where I end up.