I looked high and I looked low and didn't find this article, can you post a link? Thanks!
Found the text mentioned and pasted below:
Carb vs Fuel Injection
posted in the VAF Yahoo Group by Stein Bruch (
http://groups.yahoo.com/group/vansairforce/)
I've been reading this thread with interest, and noticed that lots of advice has come from people not yet flying...So...here's my 2 cents. And YES, I do have some experience in this area. Here's my setip. I have BOTH carb and FI...
RV6 - AEIO-360 (Inverted) with Bendix Injection
RV6 - O-320 with Marvel Carb.
FI....First, let's get all this "icing" stuff out of the way. Number one, no one in their right mind is going to mount a filter downstream of the servo in an RV, so that debate can quit. The Bendix units are not prone to icing, but the filter is still prone to collecting snow/ice, so an "alternate air source" should still be installed.
Second, it's a mechanical system that is constant flow, injecting fuel into the intake ports aimed at the intake valve in all 4 cylinders at the same time.
Benefits to the FI....
1.You can get a pretty good balance between all 4 cylinders and can lean the **** out of the engines accurately. That being said, it rarely happens without changing/tinkering with the various injectors to get them all balanced.
2.Little to no worry about icing in the servo itself.
3.No stuck needle/seat assemblies.
4.YOU CAN FLY UPSIDE DOWN!
Benefits of the Carb...
1.CHEAP-Just overhauled my MA4 for around $200.00
2.EASY Install. Van's makes a simple bracket for the cables. The FI was a pain.
3.WAYYYYY easier starting. Since the FI injection tubes rest on top of the engine, when you shut it off hot, they flood themselves. No matter what the installation, or what fishing stories people tell you, I've never seen a FI engine start as well as a carb when hot.
4.Very little to break.
5.Lower Fuel Pressure (2-5lbs vs. 25-30lbs for FI). Oh, and yes you do need a high pressure boost pump ($$$$), bypass, and high pressure engine driven pump for FI.
6.Lower Overhaul costs. FI=$750-1000.00, Carb=$200-450.00
In the end, it's pretty hard to justify a FI based on most peoples arguments. It's kind of like the TD/Nose Dragger, TipUP/Slider, 320/360, blah, blah, blah debates. The fact is that a carb will perform just as well, and produce nearly the same fuel flow as FI does. I've flown along side all of the above combinations and Carb vs. FI are usually within .5 gph of each other, assuming you have a good engine monitor which allows you to monitor all 4 cyl's CHT/EGT for leaning. If you can afford it and want it, buy it.
My first RV had FI, now my newest has a carb, because I'm cheap, and like the easy starting. That's just my 2 cents so take it for what it's worth. Drop me a note offline and I'd be happy to discuss either system.
Here's a good hint based on one of our "local" engine gods. He has an RV4 that puts out over 230+HP, Constant Speed Prop, and he works on Lycomings for a living, is a DAR, and guess what...uses a carb.
Cheers,
Stein Bruch, A&P
RV6-N664SB, IO-360 FP
RV6-N64YU, O-320 FP
Moura