Citabria engine choice: fuel inj -vs- carb

[Bowtie_1961]

Hi All,

After a lot of deliberation on aircraft type, I've decided that a Citabria would satisfy my mission of flying around, causing mischief, goofing off, and occasionally taking the wife to dinner.

I'm wondering if a IO-320 powered 7KCAB is worth looking at as a 'fun and economical' first airplane?

The reason I pose the question of injection vs. carburetion is that I understand carburetors. I've messed with them.
I have a long history as an automotive machinist, engine builder and drag racer so the concept of lean or rich of peak is understood. I don't want to start that lean vs rich of peak thing but I do want to know how a IO-320 compares to a O-320 in efficiency, power, smoothness and trouble free operation?

I can see where the injected engine may have better cylinder to cylinder fuel distribution and subsequently, EGT temps will be closer together, 'but' does this advantage equate to a better fuel burn number than a 'properly leaned' carbureted engine. With the Citabria 7 series of aircraft having both IO-320 and O-320 engines, this may be a good aircraft to base this discussion on.

The only problem I can think of with fuel injection is that auto gas is not STC'd for use in it. Also I have no concept of how the injection system works on that engine. I'm leary of things until I know what makes them tick.

Maybe I should just look for a 7ECA project with a 0-235 and enjoy (and learn from) flying with less power.
Any projects out there?

Thanks Guys!
Kenny

[182 STOL driver]

Hi All,

After a lot of deliberation on aircraft type, I've decided that a Citabria would satisfy my mission of flying around, causing mischief, goofing off, and occasionally taking the wife to dinner.

I'm wondering if a IO-320 powered 7KCAB is worth looking at as a 'fun and economical' first airplane?

The reason I pose the question of injection vs. carburetion is that I understand carburetors. I've messed with them.
I have a long history as an automotive machinist, engine builder and drag racer so the concept of lean or rich of peak is understood. I don't want to start that lean vs rich of peak thing but I do want to know how a IO-320 compares to a O-320 in efficiency, power, smoothness and trouble free operation?

I can see where the injected engine may have better cylinder to cylinder fuel distribution and subsequently, EGT temps will be closer together, 'but' does this advantage equate to a better fuel burn number than a 'properly leaned' carbureted engine. With the Citabria 7 series of aircraft having both IO-320 and O-320 engines, this may be a good aircraft to base this discussion on.

The only problem I can think of with fuel injection is that auto gas is not STC'd for use in it. Also I have no concept of how the injection system works on that engine. I'm leary of things until I know what makes them tick.

Maybe I should just look for a 7ECA project with a 0-235 and enjoy (and learn from) flying with less power.
Any projects out there?

Thanks Guys!
Kenny

Yea-Yea -Yea come back to Bruce's and bring cash for the Citabria project .John's here -Bruce is leaving for overseas today --He'll be back in 10 days.

[hotrod150]

After a lot of deliberation on aircraft type, I've decided that a Citabria would satisfy my mission of flying around, causing mischief, goofing off, and occasionally taking the wife to dinner.
I'm wondering if a IO-320 powered 7KCAB is worth looking at as a 'fun and economical' first airplane?.....

I'm sure that technically the IO-320 is a better design than the carberated version. But in real life I'm not so sure that it makes much of a difference. Maybe a hair more efficient fuel burn or a hair more power at WFO, but probably not where you'd really notice.
More importantly, is the KCAB version of this airplane the right one for you? Personally I'd forgo the inverted fuel & oil system of the flap-less injected KCAB for a 7GCBC with flaps & carberator. Not sure but the GCBC may have a foot or so more wingspan too, which would be a plus in my book. In short, the KCAB is for aerobatics & the GCBC is more for short field work-- which one would be the best for you depends on your usual mission.

[Bowtie_1961]

Hotrod150,

I see where you are coming from and agree with you about the suitability and mission.
Aerobatics would be fun, but I think I'd spend more time playing around with grass strips and pastures until becoming proficient enough to tackle more challenging strips, with proper instruction of course.

I may be wrong, but looking at the ACA web site it looks like the flap equipped 7GCBC is the only one to have the longer wings. I wonder if flaps make that much difference for someone like myself who is just starting out. Learning to slip to drop altitude past a tree line seems like it would be a kick in the pants.
I would be fun to experiment with flaps on take off to see what works best for soft/short field ops.

I still have this thought in the back of my mind that a 7ECA or 7GCAA would be a good starting point but wonder if, like my early motorcycles, I would quickly outgrow its limitations. Any thoughts?

---------------------------------------------------------------------------
Bill, if I were closer and could count on some help with that project it may be an option but
1300 miles is a long way to go. Thanks though!

[A1Skinner]

Bowtie, a 7GCAA has 150hp, same as the gcbc, but the gcbc has more wing and the flaps. I have a gcbc and the flaps are fun. Start your takeoff roll with one click, then lift your tail, and as soon as you hit 40 ias pull full flap and pull back. She pops right off the ground and she's gone, stage your flaps back to one or 2 clicks and she climbs awesome. On landings I'd say the slip is just as effective as the flaps, but I really notice the difference when I come in hanging on the prop. The pillow of air that the flaps give you make her settle down real light when I ease off the throttle, and she seems to wanna drop harder if I don't have flaps pulled.
My opinion, if your going with the gcaa, you light as well buy the gcbc. The eca on the other hand is only 115hp and not the same animal. The gcbc is fun for hammerheads and loops and such, but doesn't have as fast a roll rate as the others due to the longer wing, and can't do invertered flight like the kcab, but I don't like flying upside down. Whichever you go with I'm sure you'll like it, bit I vote for the flaps.
My .02.
David

Sent from my Galaxy Nexus using Tapatalk

[hicountry]

Bowtie..I fly an '05 7GCBC 180hp with flaps, no inverted oil or fuel, carb engine. I love the power and manuerabilty. Bought it new and the more I fly it the better I like it. Have flown the Super Decathalon and the wing on that plane is a way different wing..and no flaps. It still is not a bad backcountry performer with the 180hp. The older 'Cats are not bad backcountry planes either but the flaps really do make a difference on takeoff and landing. I just flew with a 160 hp 7GCBC with a climb prop and it is almost as fast in a climb as mine. After leveling out the 180 hp makes a real difference. If you are planning some STOL stuff I would defineitly go with the 7GCBC,
HC

[Bowtie_1961]

hicountry & A1Skinner,
Great personal insight , thanks!
From what everyone is saying the 7GCBC is the probably the most versatile in the bunch.
The motorcycle analogy I used keeps coming up in the back of my mind though. I first started riding bikes on an inexpensive Honda CB250. Then, in time, moved up to a Suzuki DL650 (I know its ugly but it served its purpose). Now I ride a GSX650F, it too serves my purpose. What I didn't do is start with more than I thought I could handle. When I was drag racing and building engines I would volunteer time and help people getting their start in the sport. First thing I'd tell them is work within your budget and learn the basics before dumping tons of dough on roller motors, narrowed rear ends, roll cages and crap like that. I think its important to have fun without breaking the bank. How much fun can you have with what you got?
We are almost to a point where aircraft ownership can be feasable. The youngest son is in Navy boot camp and all the rest of the kids have left the house. Now all the wife and I have to do is pay off expences of raising them and sending 2 out of 4 to college 'plus' moving 1/2 way across country for the wife's new job.
I'm not complaining in the least, we've really been blessed. Smart kids, good health, jobs that we like.... Life is good!
The point I think I'm trying to make is, do I really need a 150HP short field capable airplane to start with 'or' would a 115HP medium capability plane be a better starting platform to learn from?
If I try to tie my rambling together into one cohesive statement I would say that, in time, I would like to have an affordable plane that the wife and I could just go goof off and have fun in.

Sorry for the rant, its been a long day on tha ramp.

[d.grimm]

Bowtie,
My experience is by the best airplane you can afford the first time
around. Finding and buying isn't usually a really quick project, most people
don't like do it repeatly.
I would get the 150 with flaps. Flown most of the Citabia line and the
7GCBC is my favorite.
Dave

[hotrod150]

My experience is by the best airplane you can afford the first time around. Finding and buying isn't usually a really quick project, most people don't like do it repeatly......

I agree. Buying or selling an airplane can be a real pain in the ass-- esp if you're trying to do both at the same time. If you're thinking of buying a less-than-capable (for your mission) airplane just to get up to speed, then upgrading, I think you'll regret it. On the other hand, some people are perfectly happy with the 7ECA.

[Bowtie_1961]

On the other hand, some people are perfectly happy with the 7ECA.

7ECA Pilots please chime in!!!