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RV-9 IO-320 Fuel Injection issues

MarkW

Well Known Member
Friend
I am about to seal up my first tank so am thinking about the options available to me and the ones I should be thinking about before getting too far along.
Of coarse as a new builder I have many questions Landing/taxi lights, wing tip antennae and fuel tank return line. The most important right now is the fuel tank return line since I am about to close the tank. I am using the capacitance sender.
If I use the IO-320 will I need to use a return line?
It seems there are many different FI systems depending on where you buy the engine. Vans doesn't even show which system is supplied with their engine.
I would imagine I would also need the high pressure electric pump but I assume the electric is only a back-up and the engine drives the normal pump. Giving the ability to run even without power.
What about an air box. Vans shows an air box for a couple of different throttle bodies even though they show these as 0-320 engines I assume they mean IO when they say it fits a Ellison throttle body.
Anything else I should be thinking about during the wing construction.
1. Return line.
2. Antennae
3. Lighting
4. Pitot tube or AOA

Anything else I should be thinking about if I choose FI?
1. Return line.
2. Air box
3. Fuel pump and filter

Thanks in advance for your input.
 
Info

If you go with AFP FI system you will need return line. If you go with a bendix FI system (precision silverhawk) no need for return line and life is good. Some that go AFP just route return line into fuel vent line so it dumps the minimal fuel overboard. Your call.

I went with the precision silverhawk FI, no return line and 108 hrs later...love life. :) Someone on here once said keep it simple and get it flying...then worry about upgrades and additions. Worked for me. Get her flying.
 
IO-320

I am planning to use a horizontal injection IO-320 in my RV-9A. I have ordered the finish kit with an RV-7 IO-360 cowl (no carb air scoop on the bottom), Van's "snorkel" air cleaner plenum, an air filter which mounts to the left hand engine cooling air vent. Using bendix (Precision silver hawk) style injection so no tank return line.
 
Put a fitting in the tank now for a return line and cap it, then it's there if you need it. I prefer the AFP over the Bendix, but that's just me.
 
Lighting for RV

Best lighting is the Duckworx but get just the brackets and round reflector with lens. Make sure that they are for the H3 bulb. Then go to DDMTuning. com and get their HID kit with H3 bulb 55 watt. Just $50 plus shipping for two complete HID with ballasts and harnesses. Great light and low current draw that is half the 100 watt halogen bulb. For position and strobe go LED.

N174MT
 
Return line...

The return line for the AFP fuel injection does not need to be plumbed directly all the way back to the tank, only upstream from the fuel selector valve to the return tank; easily done within the cabin. The idea is to be able to flow COLD fuel from one tank, through a HOT engine to the other tank to eliminate hot start conditions... this works very well and is no big deal to pipe. Dumping return fuel overboard sounds crazy to me.
 
Repys

Good replys,

terrye,
Wow, now I have to think about the whole vertical sump thing. Are you doing this for HP or looks? Any other advantages?
Walt,
If you say API then that is what it is. I have contacted them for piping info. It looks like some are able to install without a return. I like the KISS method and don't like another potential leak source.
TangoBravo,
I saw your post one other time but when checking out DDM Tuning it looked a little confusing. I like the idea though. I was thinking about the HID and DuckWorks. I don't see that DW has a kit with round reflector. However the whole kit with the standard bulb is cheap enough to throw away the bulbs. It also looks like their retangular takes a H3. Why not use that? What color did you choose? Looks like 4500k would be best.
Dago,
Thanks. No return sounds good.
schristo,
Does the return get added only to one tank supply? Is the return only funtional during a by-pass during hot starts? I assume he meant that if you return into the vent line that some may go backwards and dump out the other direction.
 
not an active return...

schristo,
Does the return get added only to one tank supply? Is the return only funtional during a by-pass during hot starts? I assume he meant that if you return into the vent line that some may go backwards and dump out the other direction.

The return is NOT active... with the AFP fuel injection the return is from a PURGE valve, or flow diverter valve at the spider before the injectors... it is only used to turn the engine off, or cycle COLD fuel through a HOT engine. The simplest arrangement is to return to a specific tank and select the other tank when purging for a hot start... piping can easily be installed within the cabin alongside of the feed lines and terminated with a tee under the cover panel in front of the spar... not a big deal.

There are engine choices (mostly automotive based) that require an active return.
 
Ooh!

Stephen,
I get it now. You are going back into a supply and not the vent. In my mind I was not separating the two. Now it makes since. I am used to the automotive style that are active returns. API shows a new product on their website that does not use a purge valve. Maybe they have eliminated the return and the extra cable completely. That would be good.
I am waiting to hear back from API.
Thanks for your response.
 
PURGE is a good thing...

API shows a new product on their website that does not use a purge valve. Maybe they have eliminated the return and the extra cable completely. That would be good.
I am waiting to hear back from API.
Thanks for your response.

Mark, AFP does make a unit without purge valve similar to the Bendix unit... note that the ability to purge HOT fuel from the engine is a GOOD thing... you don't have to use it unless you want to. Also, using the purge to shut the engine off is nice since it completely eliminates any fuel from getting into the cylinders and stops it right now.
 
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