Fuel Injection or Carburation - Performance v. Reliability?
 

Without wishing to sink to the level of the primer debate or unnecessarily bring to mind Sam Buchanan's avatar, I am struggling with the carb/fuel injection debate for a new clone 360.
I have read various posts, Stein's article in the Firewall Forward section, and Eustace Bowhay's lengthy post on the subject on the Matronics RV list. I am inclined to conclude that one cannot go far wrong either way, given the (much more knowledgeable and experienced than I) people who reach opposite conclusions, but that still leaves a decision to be made.
For me, the top priority is safe/reliable/troublefree operation. I like the idea of fuel injection. To see all cylinders at or near the same fuel flow and temperature appeals both as a matter of mechanical elegance and good engine management. Higher engine output and better fuel economy is nice. Getting rid of carb heat would also be nice, but not a big deal either way (unless I am missing something).
But these advantages of fuel injection, for me, would be entirely outweighed if a carburettor was safer/more reliable/more troublefree. High fuel pressure lines seem less desirable than low (but is that a real concern?) Injection systems are less tolerant of debris/contamination in the system. Is that a significant factor? What is the sense of people as to safety and reliability of carbs v. fuel injection installations? Are carbs more or less reliable? Is either one less likely to leave you with a dead stick or leaking fuel? Is there any difference in reliability between a Bendix system and an Airflow system?
Bill
RV-6A (about to order an engine if I can ever make up my mind)

My vote is for FI
 

Troublefree and reliable are also my main objectives,

I have most of my time flying behind a carb, but at least 1000 hours behind Benix FI, (mainly in twins, so does that count for 2x). I never had any FI related problem other than some hard hot starts. Even that is easy to deal with once you have the hang of it. If it is put together right, FI is very relaible.

It is true, a carb is simpler, and makes the system simpler. I have had a few carb related issues, but still think the carb itself is very relaible. It is perhaps less tolerant of water in the fuel. This may not fit the population mean, but it is my experience.

I beleve that an engine with more even power distribution is subject to lower vibration. Less vibration means fewer problems over time. An engine that has more even fuel distribution is less likely to have one high EGT and burn a valve. I think there will be more engine life with an FI engine given they are equal otherwise.

In short, I have more time in carbs, but more faith in Bendix FI.

I simply don't know enough about other FI systems to comment.

I am planning to buy a new O360 clone with a Bendix copy FI for my project.


Regards,
Dale Lambert
RV-6 finishing kit
C177 (with carberetor)

views/experience as to safety/reliability
 

One vote for fuel injection for safety/reliability.
I asked the question because nearly all of the discussion in various threads to date addressing the fuel injection/carb decision compares performance of the two systems (power, mixture balance, ability to lean and fuel consumption, etc.) On these performance criteria, except for hot starting, fuel injection wins. (there is a suggestion in one thread that fuel injection systems seem to be in the shop more often).
Nearly all of us fly behind carbs or fuel injection. Is the lack of response because I truly am beating a dead horse here? Or that people perceive no safety/reliability difference? Or that there is no difference? Any engine builders or guys that repair these things have a view? Anybody have an unplanned landing because of a carb/fuel injection problem?
Bill
RV-6A (still ready to buy an engine but for this decision)

vote for FI
 

After 30 years of flying carb equipped planes, I voted for FI when I purchased an IO360 in 2006 for my RV7a. Now after 246 hours of flying the new machine, I have not regretted that decision. The economy and reliability of the FI has been as others suggested in previous discussions on the forums. My key concern was hot starts. They have been a non issue. I am pleased with my decision.

As you hinted in your first post, I think there is no absolute answer. That's why some of these topics get debated ad nauseum. :) I'm convinced FI is the way to go,as evidenced by the automotive industry. FI long ago becamethe standard, with a host of advantages widely recognized. My NIne will have an IO-320 from Aerosport power with the AP setup. Both the Vans folks and Aerosport power have good things to say aboutthe AP kit. That said, if I fell into a super bargain deal on a good, lowtime, carbureted 320, would I pass it up? Likely not. :D

To expand a little on the original question, what is the consensus on FADEC equipped engines? More complex than carbs, probably similar to electronic ignition + fuel injection... Obviously the cost is higher, but what's the downside? Is anyone out there flying a FADEC equipped IOF-320 in a -9, or an IOF-360/390 in a -7?

Thanks,
Rich

Stay away from the FADEC. One of the aerospace businesses on the field here tried it on two of their experimental aircraft and the guy behind my hanger who has it on his experimental has nothing but problems with trying to get the FADEC to work properly. The business that is run by A&P's and IA's pulled them off (I/O360 & I/O540) and the other guy is struggling to the point that after one year he is too concerned about the way his brand new engine runs (I/O360) that he still has not flown off his 40hrs. He'll probably bite the bullet and pull his off as well especially after seeing how well my engine runs.

The only thing the FADEC does for you is remove the leaning control and empty your pocket. However, I love their magazine add that goes through the process of changing throttle settings, leaning, then having a discussion of proper leaning technique with the co-pilot.

After years of flying carb planes, mine is the first that I've flown that has FI. I love it. Very smooth running, easy starting even when hot once I figured out the best procedure to do it, fuel efficient, and no worries about carb ice. Coupled with the Lightspeed II it has so far been a joy.

Hmm. Do you recall whose FADEC product they were using (there's at least 3 out there I can think of), because the Aerosance website suggests they don't do one for the IO-540?

After a little more digging, everything I can Google or search says it's a Good Thing, if you can live with the price. Aside from the gee-whiz factor, and efficiency improvement, I'm mostly interested because it means one less knob to consider when I find myself in a bad situation...

Two points for you here...

1) - Consider the source of those "good thing" comments - they probably have a dog in the fight and may very well be acting as cheerleaders for FADEC, even if for no other reason than to make themselves feel better about writing that big check.

2) - One less knob to consider in a bad situation is a good thing - unless the absence of that knob is actually the cause of the bad situation. FADEC's can be a valuable tool when they work right - and if/when they don't, you don't have a Plan B to go to. Personally I'm a control freak with anything mechanical - give me the levers, and I'll do the thinking. I might use an auto-tool for 98% of the actual time spent pulling those levers in order to reduce constant workload, but when the auto-tool quits auto-tooling, I want the levers available for me to push/pull myself.

can you run auto fuel in the FI? i must me able to run some form of autofuel due to living on a private strip. thanks