ECI return lines GPH

[Neal@F14]

Does anyone know what are the typical GPH flow rates of the return line of the ECI Titan EXP fuel injection system at idle, cruise and full power settings? The engine is an IO-360.

Also can the ECI system be run with the return blocked off completely like other brands of FI systems? Or does the ECI system absolutely, mandatory, must have the return line free-flowing at all times in order to function correctly and not experience some kind of overpressure condition?

The reason why I'm asking is that I have a friend who's installing one and he's insistent to only plumb the return to one wing tank only, which I think is going to make fuel management a hassle if the return line's flow rate is significantly large.

If the ECI system can tolerate the return line being shut off completely and still meter fuel properly, then the single tank return could work with a simple inexpensive shutoff valve inline to prevent overfilling that tank and blowing large amounts of fuel out the vent when running off the other tank. That would still give the option of manually engaging the return to help cool off the system for hot starts when switched to the tank that has the return line plumbed.

[JESSEAERO]

The ECI fuel system is the same basic system as the Continental IO360 system. It is a constant pressure system that requires the return to the tank. It serves two purposes in that it returns any extra fuel to the tank as well as any air that may be in the system. Without the return it could cause vapor locking and hard starts.
I think it would definitely be best to do it to both tanks while he has easy access.

Jesse

[KPmarc]

Neal:

My understanding of the system, which is just like a TCM design, is that it absolutely must have the vapor return line operational. No question there.

As for the flow, I believe it depends on engine speed and mixture setting, but it could be 50% of the actual consumption rate. That strongly suggests against a single-tank return line.

Moreover, I can tell you from experience flying very early Bonanzas, that you don't want a single return point from a pilot workload perspective. In those old Bonanzas, with two small inboard tanks and a pair of outboard auxes, the return fuel went back to the original tank when one of the mains was selected. But when one or both of the auxes was in use, the fuel return went back to the left main tank only. So you had to run down the left main quite a lot to make room for the overflow from the auxes, and be prepared that, say, the 10 gallons in each aux tank would not last two hours at 10 gph.

Plumb it the way ECI recommends.