Rotax Fuel Injection

[Bill_In_Diamondhead]

Anybody installing a Rotax Fuel Injected Engine in their RV-12? Somebody has to have done it. I do not want Carburetors in my airplane.

[aerofurb]

I doubt anyone will fit the 912iS in an RV-12 as a 'mod' from the standard installation unless Van's eventually offer it as an option.

The 912iS is a relatively complicated installation over the standard 912ULS because of the electronic fuel injection and ignition systems. Lots of boxes and wires to add.

Do tell why you hate carburettors?

In my humble experience they work just fine in aircraft including RV-12s.

[bhassel]

Here's a great video that shows what's involved in the process...it's not just a swap...

https://www.youtube.com/watch?v=TzTieV0EvSY

Bob

[epaslick]

Originally Posted by Bill_In_Diamondhead

Anybody installing a Rotax Fuel Injected Engine in their RV-12? Somebody has to have done it. I do not want Carburetors in my airplane.

I asked a similar question a couple months ago and got a either response of "That would be really hard to do." or a horrified response of "Why in the world would you EVER want to do that?? The RV-12 with the 912ULS is perfect as it is!!" from the participants of this forum (this in spite of the fact there are RV-12s flying with both Viking and Jabiru engines installed).

Here is a link to that thread: http://www.vansairforce.com/communit...d.php?t=121720

I have since kept my head down low to avoid the crossfire...

[bhassel]

I would love to see the 912IS or the 914 turbo as options. I'm just not educated enough in the correct areas to figure it out.

I even heard somewhere that Cato was working on a fixed pitch prop for the 12 that would shave off enough pounds to make the weight work out (or close).

Leave the head up and someone figure it out...please...

Bob

[rv6ejguy]

http://webshop.edgeperformance.no/index.php Has EFI, big bore and supercharger kits for 912 engines.

[sthopkins]

Granted, this was a test stand installation, but I've swapped a 912iS in place of a 912 ULS and run each ~40hr. We flew the ULS quite a bit. As with any installation, efficient cooling is the biggest issue.

There are more boxes and wiring, and some extra weight, though the iS absorbs some of that difference in internalizing some electrical equipment (weight includes the necessary redundant alternators). We did find that the iS maintained better mixture control and power over a range of conditions with less adjustment and had slightly lower fuel consumption.

I have a hard time imagining a net benefit to going to the iS in the -12. As others have said, changes to an existing installation add time and cost, and the extra cost for the engine itself is considerable IMO. We were considering the swap primarily for marketing reasons and also for better engine control over a range of power settings (which doesn't apply to typical aircraft). Honestly we never had an inflight issue with the carbs after proper jetting.

Compared to the typical motorcycle carb bank arrangement, the Rotax setup is pretty simple and accordingly easy to maintain, and the conditions of flight in a non-aerobatic aircraft lessen the benefits that are observed in going to FI on a car or motorcycle. That said, if your decision is based on ideology (your own or your friends) then you're going for it either way!

TLDR: In my mind the swap wouldn't be super complex (compared to installing a panel, for example) but making it a clean installation would take time and would likely not be worth the slight benefits.

[kbehrent]

A couple years ago we took our TeenFlight kids down to Van's to pickup one of our kits and to meet Van. I remember the topic of supporting the fuel injection engine came up and I recall that Van had said that he thought it would require significant change to the firewall forward kit thus increasing the kit cost. Add to that the cost of the more expensive engine. I believe his opinion, at the time, was that it was unlikely that the majority of customers would be willing to pay the extra cost. Realistically, you could buy years worth of gas for the extra cost of the kit mod and engine.

I have no idea if that is the official stance of Van's Aircraft now.

[MrMorden]

Originally Posted by Bill_In_Diamondhead

Anybody installing a Rotax Fuel Injected Engine in their RV-12? Somebody has to have done it. I do not want Carburetors in my airplane.

Personally, I don't think the 912iS makes much sense in an LSA where gross weight is limited. You are going to pay $12k more for an engine that weighs 20-25lb more.

Also, if you lose electrical power, you lose the engine. That means redundant everything for the electrical system and yet more weight.

The 912ULS is a well tested engine, and the Bing carbs are pretty easy to care for. While carbs are not ideal, in this case they make more sense than the alternative.

[RFSchaller]

I just took the ROTAX course about 6 weeks ago and asked about swapping to the 912iS. It looked like it would pose some Cg issues, require major alterations and the interface box to talk to it for maintenance costs $1000. I came to the conclusion it was not worth the trouble to convert at overhaul time. I might change my mind if someone did all the engineering and parts development to offer as one package, but it was well beyond what I wanted to tackle.