Convertig to Fuel Injection ... which brand?

[swisseagle]

Hello

I'm planing to convert my buddy's RV-4 with a O-320 into a RV-4 with Inverted oil and fuel injection, this autumn.

Inverted oil will be a full Raven system, by the fuel injection I'm unsure to decide. Here are my two favorit from which I should choose soon:

1. Precicion airmotive, Silver Hawk EX
- Well known
- 10-15 years in market
- Installation manual
- Good and bad experience with customer support (from VAF members)
- Two RV-Buddy's fly such a system and are happy so far, but they do no aerobatic

2. AVStar, AVX320-1
- New, computer flow optimized
- No installation manual, but telephone support
- Good and bad experience with customer support (from VAF members)
- New system needed to go back onto the bench for adjusting ...
- One RV-Buddy fly such a system, never saw a engine with all the temps so close together and each cylinder is reacting on the spot with all the others, superb!

I like "New" things, things that where optimized on the knowledge for actual experience. Because of this I tend to no. 2, but the lack of Installation manual and that
a few VAF forum members say that it was the wrong decicion to go with AVStar ... pull me a bit more to no. 1.

Which one would you choose and why?

Thanks for any assistance!

[jthocker]

I have the AvStar. Didn't have a need for the manual as I just bolted it on and hooked up the cables, hoses, and injectors.
The stock injectors reach peak at almost the exact same time. My "GAMI" spread is immeasurable.

[DanH]

There are at least nine choices available at this time, and I could be forgetting somebody.

Constant flow: You've already mentioned Precision Silver Hawk and Avstar. Add the Airflow Performance FM-150, the SkyDynamics system, and of course, the trusty Bendix RSA-5.

Electronic fuel injection would also work fine inverted. Precision offers the Eagle EMS. Simple Digital System (SDS) offers the what is arguably the most advanced system keyed to owner-install. EFII sells an SDS-based system with fewer features. For the more DYI crowd, let's not forget Megasquirt.

Recommendation? I'd pick the AFP FM-150, or SDS, because (among other reasons) both offer extremely good manufacturer-direct support. The FM-150 would be far easier to install in a conversion, as the SDS (like any EFI system) requires adding significant electrical infrastructure, plus a tank return. (BTW, an FM-150 has no purge valve or tank return.)

My personal second tier would be Silver Hawk or Bendix, as every decent aircraft maintenance person in the world knows and understands them. They are functionally the same. I really don't know much about the AvStar system, but it seems to be coming on strong.

In terms of performance, you can probably throw a blanket over the entire list. There are no losers, just subtle and not-so-subtle differences and details.

[TS Flightlines]

Just remember on the RV4 with a full return system, its going to get crowded with all the plumbing. Duplex valves are pricey, + the costs of the extra plumbing.

Tom

[TCONROY]

The IO-360-M1B that came from Van's for my RV-7 had the AvStar system installed at Lycoming. I've had zero issues, even temps, and a very small GAMI spread (I did end up tightening up the spread with a restrictor in one nozzle).
I would gladly install another AvStar system on a future engine.

[Toobuilder]

Originally Posted by TS Flightlines

Just remember on the RV4 with a full return system, its going to get crowded with all the plumbing. Duplex valves are pricey, + the costs of the extra plumbing.

Crowded, but "doable". This is the whole thing stuffed into the stick well of my Rocket. (Modified SDS fuel pump module shown)



And due to the currently favorable exchange rate, the Andair duplex valves are now reasonable.

[swisseagle]

Thanks to Jon, Dan and Tom, great info!

I have personaly on my RV-7A a FM-150 on a TMX-IO-320. It runs ok, but needs adjustment of idle mixture and idle twice a year due to weather change. Idle mixture change is a hassle to do ... on the others you just can turn a screw in the correct direction and fine it is. On the FM-150 you have to lose up two nuts and the fun starts. I also had a flake in the divider that was blocking the piston in it, even more idle problem and it wont take power immediatley. That is now solved, still the hurdle with the Idle and idle mixture.

@ Tom: I know it will be not so funny to route all the tubes ... but for sure we will go with you again And NO return line!

@ Dan: SDS or the EFII system are really interesting ... but backup power and backup injection ... I dont want to rebuild his plane ... enough to do to make it sportsman-ready ;-)

@ Jon. That is what one on my RV buddy's see too! And that is what we like to see also :-)

[JonJay]

Is your goal to just go inverted or do you want the other benefits?

[swisseagle]

To go inverted without a mess/oil on the plane and with engine-power without interruption during the inverted and 0g phases.
With the carburator now, it can really take a moment to get power back ...

[RV10inOz]

Precision for sure.Airflow Performance most likely the better option. Avstar no.

I will give you a tip. All new Avstar and Precision less so units are being re-benched down here because they are not set up right out of the factory. Don Rivera at Airflow I believe gets them right from the start.

YES IT MATTERS.