Carb vs FI

[Gorilla]

I'd like to hear opinions from experienced homebuilders and/or A & P guys on the fuel injection vs carburetor debate. I am eventually going to build an experimental with probably a variant of the O-360. I used to believe that the carb engine would cut-out or run intermittently under 0 or slightly neg. G, but I've heard there is a carb system which will perform just fine during mild acro.

From what I've gathered:

Carburetor - Easy start both cold and warm, less expensive, simple maintenance

FI - Better performance, easier to match cylinders/EGT for leaning, better fuel economy.

I appreciate your inputs, thanks!

 

[DustMaker]

I would not put as carb in an air plane - two words - carb icing - go to faa accident records - do a search on carb icing - toooooooooo many planes bent up and people dead

 

[USMCmech]

It depends on your budget.

If you can afford it, I would deffinately go for the IO-360. Nothing wrong with carbs, but injectors do everyting carbs do, only better.

There is a reason not any automobile manufactured today has a carburator.

 

[Gorilla]

Thanks guys. What's the issue with difficult hot starts with FI? Is it the truth, or is it the result of "Ham-Fist Johnny" not following the correct procedure?

 

[GravityHater]

The heat of the recently stopped engine radiates to the fuel distribution lines which are often above the cylinders, this heat is intense enough to vaporize the liquid fuel in the lines. Easily cured by correct application of the primer and engine controls. The vaporization problem does not happen when the prop is turning because there is adequate cooling flow.

 

[sleddriver77]

Depends on the airplane and how it's used. Especially if you're going to be doing any aerobatics. Will a carburetor run upside down? Sure, for a few seconds. As far as "hot starts" go, is this IO-360 the lycoming or continental? FI Lycomings love to flood/vapor lock when warm. Usually, if you don't touch the mixture until after it fires, it'll start. FI continentals are comparatively "cold blooded", and need to be primed (A LITTLE) even when warm. The injection system will probably cost about three or four times what a carb would (again, depending on whether lyc/cont) There is a company that makes a "copy" of Precision's lycoming fuel injection systems, look on the net, you'll find 'em. As far as continental, I think you'll probably need to use the actual Continetal CFFIS due to all the pumps and such.
If you're just gonna motor around rightside up on dry days, a carb is just fine. They've been using them in airplanes for about 100 years now, right? But, make SURE you have EFFECTIVE carb heat. I have two projects in progress now, a Flybaby and a Skybolt. Flybaby is gonna be a small continental with a carb. Why overcomplicate a little "putt putt" airplane? The skybolt is IO-540 powered. I'd like it to breathe as much fire as my budget allows. I guess it depends on how you want to use the airplane.

$0.02