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Fuel Injection vs Carb

fabricflyer

Well Known Member
I'm fairly new to the forum, so this has probably been discussed, and I know it is like "Slider vs Tip Up", but I would like to hear some comments on fuel injection vs carb. I've got to order my finish kit, so I'm trying to decide which to use.
Thanks ahead of time for comments
 
Good subject to discuss. My thoughts:

Fuel Injection is more fuel efficient, plus you can go inverted (oil system and fuel pickups allowing) and you don't have to worry about carb icing.

A drawback to typical fuel injection is hot restarting. You need to develop the right technique for your setup. Some fuel injection systems require a return fuel feed to the tank, but not sure which ones.

I'm planning to go a step further and getting the Eagle EMS or another FADEC type system. Full ECU controlled injection and ignition. I like the idea of not having to mess with mixture and getting even more fuel efficiency. And engine starts are no hassle, hot or cold. :)

A Carburetor benefit: Some cost savings.
 
Carb ice

One thing that I keep seeing here in the UK, which has a humid maritime climate, is the number of accident reports stating possible carb ice as the cause.
Injected engines tend to run smoother and burn less. More up-front cost but less fuel burn.

Peter
 
Don't let the issue of hot starts influence your decision - as stated that is easily and reliably overcome with proper technique. I've been flying FI Lycomings almost exclusively for years in temps ranging from below freezing to 120+ and can't remember the last time I couldn't light one off in the first few blades.
 
Good subject to discuss. My thoughts:

Fuel Injection is more fuel efficient, plus you can go inverted (oil system and fuel pickups allowing) and you don't have to worry about carb icing.

A drawback to typical fuel injection is hot restarting. You need to develop the right technique for your setup. Some fuel injection systems require a return fuel feed to the tank, but not sure which ones.

I'm planning to go a step further and getting the Eagle EMS or another FADEC type system. Full ECU controlled injection and ignition. I like the idea of not having to mess with mixture and getting even more fuel efficiency. And engine starts are no hassle, hot or cold. :)

A Carburetor benefit: Some cost savings.

How much extra does the full ecu thing cost that sounds cool
 
Man I hope those come down in price how cool is that. Ill bet engines with those last longer.
 
There is not one good reason to buy a carby engine for your RV.

Not one. Not that anyone has ever explained well enough to me so far.

Not even cost.

Go the IO :)
 
There is not one good reason to buy a carby engine for your RV.

Not one. Not that anyone has ever explained well enough to me so far.

Not even cost.

Go the IO :)

Reminds me of one of my favorite sayings... "NEVER use absolutes!!" :D

Let's see, carbs have a lower cost, are simpler in terms of fixing, easier to troubleshoot in the field, use a cheaper boost pump, more tolerant of a little contamination.....

And yes, I have an IO on our new plane, as well as carbs on our older planes, and they both have their place. I certainly do like the way the IO runs!
 
I say carb

due to cost, if you don't think so, spend the extra coin and have a nice flight, I'll be right along side ya.:D

Randy
8A
 
Simplicity / Cost / Decision Making

The carb is a bit more simple system, saving a few hours in construction. You might save $2-3K in the carb over FI with the cost of the engine and fuel pump(s). (the costs between new carb and FI engines is negligable nowadays.)

You can run dual p-mags on both carb or FI. I suspect that running Dual Pmags on a carb would increase fuel efficiency and smoothness to levels similar to the FI or better.

In the low wing aircraft both need a boost pump (aux / back-up fuel pump to the engine driven pump) associated switch and breaker. (Different type/pressure pumps of course!) You might prefer to also add an electric primer (switch and breaker) to the carb system, although not necessary in most climates, i'm told.

You will need to make a decision towards finishing of the fuselage, for running fuel lines in the forward cockpit - and prior to ordering the Firewall Forward and Finish Kits.

On the Front Page of VAF - under the "Firewall Forward" section on the Left, there is a good article on the subject.
 
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There is a third choice; Throttle body - Ellison, Rotec...
My 6 is injected and I like the fuel economy on long trips running LOP. If I was going to use my airplane much for cross country adventures the FI might pay for itself in time, might...
The Bucker has an Ellison. Good for inverted flight but it is not my choice for long trips.

Two airplanes, two different missions generally speaking.

If most of my flying was local hamburger runs and EAA meetings, I would be hard pressed to justify the FI costs, but in relation to the rest of the build, it is really not a major investment.

So, 50/50.....Nice to have choices though....gives the fine folks at VAF something to argue about, I mean discuss.....
 
I have a factory new YIO320D1A from Vans. I didn't make my decision until after I had the cowl. I had to cut the snout off my lower cowl and buy the deeper snout from Vans to fit the fuel injection servo. That was a fair amount of work on the lower cowl I could have avoided if I had made the decision to go FI up front and ordered the correct lower cowl.

The FI model was only a few hundred dollars more. Flying two years....the engine starts easily cold or hot, even at 110 oat on the ramp. Just follow Lycoming starting instructions. I have flown many large bore Continental and Lycomings FI engines over the last 45 years, but this YIO320 has been the easiest starting and smoothest running of them all. And yes, it has the roller lifters. It does not use a fuel return line to the tank. I paid close attention to insulating all fuel lines to the servo in the engine compartment with fire sleeve and blast air to the fuel pump. I would definately go FI if I build another RV.
 
I received a quote today from Aero Sport Power. The additional cost to go with the Eagle EMS Full Electronic Fuel Injection/Ignition system is $5,000. Some of that is probably tuning.

Hmmm... I need to decide if this is worth the slightly higher efficiency and never having to worry about a mixture knob. :)
 
IO vs Carb

Reminds me of one of my favorite sayings... "NEVER use absolutes!!" :D

Let's see, carbs have a lower cost, are simpler in terms of fixing, easier to troubleshoot in the field, use a cheaper boost pump, more tolerant of a little contamination.....

And yes, I have an IO on our new plane, as well as carbs on our older planes, and they both have their place. I certainly do like the way the IO runs!

Agreed on the "Never use absolutes." It just invites drama.

RV's with IO fuel vs Carb. I have had both: a 6- w/carb O-320 and now a 7- w/IO-360. I liked them both. The IO 7- has advantages of some better fuel management although not much. Starting hot is not a worry. Just learn how.

The big thing to me is simplicity, which usually equals dependability. That is where the IO looses over the carb. I have heard sooo many stories about IO problems it is amazing. Chasing down IO problems can be a time consuming issue. Even when done by a competent A&P.

IO systems make more efficient engine operation. Many are lucky having no problems with their IO systems, although I know of many that have had issues or ongoing issues with their IO system. Many A&P's also report frustration with multiple issues on IO systems. They spent significant time having the problem or problems chased down, repaired then on to the next issue. When IO is running good, they are great and I like them. IO systems just have more areas of vulnerability.

Carbs are simple and work. They have issues also although they are simple. Some have mentioned, carb ice, but is easially managed. See Ironflight's comments above. Ironflight is one of the best respected on this site. My flight mission is mostly xcountry long distance 400-1K, so my IO system is the ticket for me. If local and short flights (400 miles or less) was the usual with occasional long distance trip, I would go with a simple and dependable carb and emags. As usual, depends on the mission. Just my thoughts.
 
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