IO-360 typical fuel injection system arrangement

G'day VAF!

I have decided that my RV-7 will run a Lycoming IO-360-B2B with a FP Sensenich 2-blade alum prop.

I have a vague idea on the requirements of a fuel injection system, which can be summarised as:

• Fuel flow meter
• Fuel return line

I have no idea if these requirements are valid or if there are others I am missing.

I'm just pre-empting what I need to install in my wings. My wing kit is shipping to Australia in June sometime and if there is anything else I need to add to my order from Vans, I would like to do so now rather than later.

If anyone has any advice, I'd appreciate it.

Cheers,
Gav

A return line is only required for some systems but not all. So that depends on which system you are using. A flow meter is a good idea but not necessary. You could manage fuel usage with a simple metered pressure gauge or even EGT. Not the best way, but doable. You will also need a boost pump capable of 15-25 psi at a flow of about 20gph.
Good Luck,
Mahlon
"The opinions and information provided in this and all of my posts are hopefully helpful to you. Please use the information provided responsibly and at your own risk."

Hi Gavin.

Don't use a return line unless you have to. My -10 doesn't have one and a lot of my friends injected engines don't either....more work and more chances of leakage.

You'll need an electric boost pump with enough capacity for the injection system.

Depending on the instrumentation, the fuel flow sender will need to match...e.g. Dynon might use a different sender than GRT or the others.

Best,

The AirFlow Performance system which many folks use (FM200) does require a purge line back to the tank. AFP now makes a system that does not require it (FM150) but I think the original FM200 system is superior. Being able to purge hot fuel from the system is a real advantage (especially in hot climates) and will prevent vapor lock on quick turn arounds.

The Precision Silver hawk does not require a purge line.

The purge line is almost like a vent line, no fuel flows through the line unless you are purging and is at '0' pressure. I see no reason not to install it and many reasons to install it, the advantages far outweigh the disadvantages in my opinion.

Fuel Flow, not required but REALLY nice to have!

hello down under

As previously stated, needed items are a boost pump/filter (AFP, Andair, EFII or similar).

I rely completely on my fuel flow meter and EIS4000 to monitor fuel flow and fuel on board. It has repeatably proven accurate to within 10ths of a gallon for 200 flight hours. I have not been able to make my Prince capacitive senders work at all. I suspect that the vans capacitance system (or even mechanical senders) is much better.

Fuel flow meter location is much debated (search forums) but I suspect no one will argue that between the fuel control and the fuel distributor is the optimal location.

With most injection systems (Bendix, AFP 150 or Precision Silver Hawk) no purge/return line is needed. With proper starting precedures (and an electronic ignition) I suspect that most will agree that the need for purging for hot starts is a minor issue. Don't got a purge line with my AFP overhauled Bendix RSA fuel control, and have no reason to believe I need one.

The next big question when you get to the fuse and finish kit stage is whether it is vertical or horizontal induction. I believe that the B2B is vertical. In that case, you need to let Van's know the engine choice so that you get the correct cowl and intake set-up. There are also some specific throttle mixer cable lengths and cable mount brackets for throttle and mixture for that set-up - again, van's can supply the appropriate ones if they know the engine/injector choice.

Sounds to me that at this stage (wing kit), return line or no and capacitance or mechanical senders for fuel ndication are the only decisions to be made.

Hope that is the info you were looking for. G'day

If you happen to choose the ECI Titan fuel injection system, then you'll need two return lines... one to each tank, plus also an expensive Andair duplex fuel selector valve (think of a DPDT switch, but for plumbing instead of electrical wires)

The ECI system is rather expensive and complicated to install and calibrate, but once done, then it's such a smooth and sweet running system, and hot starts are child's play.

Is it worth all the extra expense and hassle above and beyond an AFP or Precision system?

I dunno.... probably not. But I sure like flying behind the ECI

And as to the fuel flow monitor... after flying behind a Dynon D120-equipped IO-360 for 50 hours, my opinion is now that a full color-screen EMS system ought to be mandatory for a fuel injected engine. The amount of realtime information you get all on one screen really lets you know precisely what your engine is doing like nothing else can.