What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

RV-9A build consideration advice

C

CaptPausert

Active Member
All I am currently build an RV-9A I have the empennage about 80% complete awaiting LCP replacements and the wings about 20% complete getting ready to rivet on ribs and starting in on the fuel tanks.

My current plan for the build is as follows

Engine O-320 with FlyEFII system32 fuel injection and ignition
Prop 3 blade Catto

Wingtips Aveo ZipTips. (would prefer the new wingtips with the AeroLEDs but they are not making them for the 9.)

Avionics Garmin G3X with autopilot

Was going to use a Sam James cowl but that may be on hold due to the no parts deletions. depends on if I could find a buyer for the stock cowl shipping it is going to be a pain though.

I know I need to add an extra fuel connection on the tanks for the return line for the system32. Is there anything else with this build that those with these items know I need to build into the wings? Planning on finishing the wings this spring and starting the fuselage early this summer.

I have an A&P friend that is going to help me rebuild an engine to save money good thing too if I had to order an engine at current prices most of my upgrades would be going away.
 
Installation of a duplex fuel valve so that when you select a tank, you are also selecting the tank the return line is feeding.
 
Standard fuel tubing arrangements (IO-320) were an assembly nightmare for me. At my skill level on my next RV, choosing a fuel system requiring a second set of return lines is a non-starter. A friend recently did that on an RV-7. Even without the -A gear leg mounts (which are designed specifically to thwart every possible straight tube), it was a head-scratcher, but he managed to push through fabricating home-brew cover plates with bulges. Installing my simpler set of fuel lines became one of those junctures in my build where I became sick of the whole dang thing.
 
I am sorry to be the one with this advice, but having just completed an RV9A, I have to ask, why the non-standard fuel system?
As a point of reference, I have a factory IO320 in mine with a Catto prop. The standard stuff works great. I would be interested in what the benefit you see in the non standard (non-Lycoming) fuel system?
I have the full G3X suite and love it; that is well proven.
 
A couple of reasons. It isn't that experimental there are quite a few RVs flying with the FlyEFII system32 fuel injection and ignition system. I think it is mostly RV-10s but there are a few RV-7s as well. It also allows you to use 9:1 compression and still use 91 octane. I think that is a good thing if the 100LL replacement goes bad. It also has a bit of extra HP and fuel savings in cruise.

The extra complication of the install isn't really that much of an issue for me. I am fairly confident in my ability to figure it out and if I run into an issue I have an A&P friend that has a lot more experience who can help me out. As there are quite a few people who have done the installation before I think I can figure it out and that the benefits outweigh a bit of install difficulty.
 
Drill the holes for the second 1/4" pitot/static pressure through the wing ribs NOW while building the wings, not 15 years later. I just added the Garmin GAP26 pitot tube so I can use the AOA function in the G3X. My wing ribs came with 2 holes near the spar, one for the pitot tube and one for wing tip and OAT wiring.
 
“It also allows you to use 9:1 compression and still use 91 octane. I think that is a good thing if the 100LL replacement goes bad. It also has a bit of extra HP and fuel savings in cruise.“

As compared to what?

Any EFII system will not produce more power or gain fuel efficiency over a standard mechanical injected Lycoming running pMags. Efficiency gains in cruise are mostly a result of timing advance - which is provided by EFII or a good EI. An engine running 9:1 pistons can be detuned enough to run 91 mogas - this is not unique to EFII.

EFII does what it does, but there no free lunch. EFII does add cost and complexity. A lot of people like it so you decide if it presents a good value for you.

Carl
 
when building the fuel tanks, make the upper tooling hole in the internal tank ribs larger. This allows the air to vent during filling, preventing sloshing and a general mess when the FBO is trying to fill too fast. I think I did mine at 3/4". I never have a problem filling at full speed.
 
Be aware that with a 3 blade prop, getting the lower cowling on and off is a serious challenge. Most people end-up making the bottom snorkel removable to facilitate getting the lower cowling on and off.
 
I would seriously consider a 180 hp IO-360.. I fly a -9a with a CS prop, and I really wish it had more climb capability.. it really runs out of steam at 12,500 and above.. yeah it will get to 14,500, but I would rather have the extra power to climb..
 
I have the Catto 3 blade as well and it’s certainly not easy to remove and reinstall but with practice I do it myself, thankfully not very often. Having the 3 blade Catto is well worth it.
whats not worth it is the downside of a fully electronic FI. Even if you have marginal efficiencies gained an electrical outage means an engine outage. I’m sure thats obvious but its a completely unnecessary risk. With an IO320 stock injection system you have an outrageously reliable (drip) low pressure system. Its just my own opinion of course. I have a triple redundant electrical system but if I loose all power for any reason I’m still flying with the IO320 (Or O320 of course).
Hope that perspective helps.
 
You must log in or register to reply here.
Back
Top