Quote Originally Posted by turbopilot View Post
Could someone from CubCrafters or ECI comment about whether this conversion can work in the Carbon Cub. I would be inclined to do it on my E-LSA if it appears feasible.
Bob, the CC340 is not fuel injected for one primary reason... weight. Fuel injection would require an engine driven fuel pump, an aux fuel pump, a filter, and a servo (which is heaver) in place of the carburetor. What would those weigh? I don't know but I think it would be in the ball park of 8-10 lbs.

That might not seem like that much but you need to understand that in order to get an entire aircraft of the size and performance of the Carbon Cub to make the LSA max empty weight there had to be a mindset that was fanatical on weight awareness. That mindset had to manifest in every single aspect of the aircraft, if we hadn't then the Sport Cub / Carbon Cub wouldn't exist as an LSA. Yes, certain compromises in the interest of reducing weight had to be made, anyone who has taken all the screws out to remove the cowl is aware of one of them, and reverting to an old fashioned carburetor was another. As with all things in aircraft design compromises are required.

No question a fuel injection system would provide better fuel distribution, improved LOP operation, and probably a small bit of extra power. Yes, it could be retrofitted if one had the time, determination, and willingness to solve some potentially difficult problems on his/her own. Are you up for it? Having built two aircraft myself the conversion would be attractive to me and I wouldn't be afraid of the challenge, only the weight. Still, with my company hat on I'll neither encourage or discourage the idea, it's your aircraft and it's already been converted to an ELSA so it's entirely legal.

Now, in terms of fuel injection systems, you really have three choices:
1. The ECi system (newly available)
2. Silver Hawk EX from Precision Airmotive (the experimantal version of the original Bendix design)
3. Airflow Performance (very popular with homebuilders but it requires a return fuel line)

Once the F.I. system is installed the airflow still won't be even to each cylinder, that's a function of the intake tubes which are too space constrainted to be optimized, but you can adjust the size of each fuel injector to get the fuel/air ratio right and to peak at almost the same time. I've played with this myself a fair amount, click here for the story of what I did on my RV-3B.

Hope that provide some perspective.