What's new
Van's Air Force

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

Rotax 912is Option?

From https://www.facebook.com/notes/vans-aircraft-inc/rotax-912is/381492068527838

Yeah, we saw it too - Rotax has released a new fuel-injected version of their 912 engine.

We?d been aware of this project for some time, and the concept is exciting; but there are several reasons that, in its present form, the engine is not suitable for the RV-12.

Weight: The Rotax press release says the f.i. version weighs 6 kilograms more than the carbureted version. For the metrically-challenged, that?s 13.2 lbs - a significant increase and difficult to absorb, given the RV-12?s forward-cabin configuration and legally limited gross weight.

Size: The photos accompanying the Rotax press release make it quite clear that the engine will not fit in the RV-12 cowl. Re-designing the cowl and making new molds would be an expensive and time-consuming project, increasing the cost of the kits.

Cost: We haven?t seen final numbers, but the new engine is likely to be priced significantly more than the one we use.

We will consider the pros and cons of the new engine, but for now and the realistic future, we have no plans to offer it, either as a replacement for the existing engine or as an option.
 
Go for it!

If you can afford it and have the time and want to do your 12 EAB, then go for it. No doubt that someone will and no doubt, it will be successful. Are you that one?
 
I talked to the rep at AOPA and asked this question. He said too much of it is based around the existing design and didn't expect that to change anytime soon.
 
VANs not convincing!

I was never convinced by the main argument of VANs (I will pass on the even more ridiculous cowling issue): 13 more lbs of weight. Come on, this represents 2 Gallons of fuel or just 43 lbs of baggage instead of 50 or... make your pick out of this statement from VANs RV-12 brochure:
"two 210 lb people, 20 gallons of fuel and 50 lbs of baggage ? something rare in the Light Sport Category." (the healthiest pick being two 200 lb people... with lbs to spare!)
What about this more convincing reason:
"We are just out of a harrowing retrofit that we underestimated by almost a year and which created mayhem among our RV-12 builders so, we are not doing it again anytime soon"
The Rotax 912is will come when VANs gets over this, mark my word! :D
 
Updating'improving

Seems like a natural progression to facilitate installation of this engine for those who want it. It would require updating and re-certifying the kit and therefore, be expensive - I hope that Van's can afford to do this.

Guess it would depend on how many of the updated kits Van's would sell. Bottom line is economics and the future doesn't look good for me, at least. I'll be happy to someday have a flying RV-12!!!
 
Look into my Crystal ball!

My crystal ball says that will happen in about
5 years so don't hold your breath.
 
Rotax 912 fuel injection.

My hope is that Rotax will quit selling the non-injected engine, thereby forcing Van's hand. I know people would howl, but what's an extra $4k out of $70k?

Jerre

For 4K you can put Airflow Performance Mechanical fuel injection on a 912.
The system has been flying for the last 3 years.

We posted this system about a year ago but had no takers due to cost. If you guys are interested in a installation on the RV-12, let me know.

Don
 
My crystal ball says that will happen in about
5 years so don't hold your breath.

May be Rotax will find out that there is no point keeping manufacturing two engines with the same 100 HP output when one is clearly superior. The main justification to keep producing the carburated one would be price to fight competition. Do you know of any LSA engine that threatens Rotax supremacy? Five years from now, may be, and this one would sure be injected anyway.
My crystal ball tells me that the drop in orders for the carburated 912ULS will be so steep that within one year Rotax will announce they discontinuing it as of 2014. They might continue with the 80HP though.
 
We've had EFI flying on 912 engines for the last 4 years. Initially there were few takers and we shelved selling the complete packages, just trickling out some of the CNC'd parts so people could come up with their own intake manifold solutions for each airframe type.

Once Rotax announced their IS option, interest grew significantly so we have partnered with Edge Performance in Norway to provide complete EFI packages for the 912. They will also be offering a turbo 912 version. Edge flight tests everything they sell which is something we demand in our aviation vendors.
 
Last edited:
.....the future of the -12 as LSA....?

As Van's is now manufacturing and selling complete -12's as LSA, it makes so much sense to invest now in something that lens itself to FADEC for ease of use and operation......surely Rotax/europe is close to this, as are all these aftermarket responses to consumer demand.
as others have intimated.......The first big order from a flight school may just push the issue over the top!
 
If you can afford it and have the time and want to do your 12 EAB, then go for it. No doubt that someone will and no doubt, it will be successful. Are you that one?

Won't be me. Sorry. I am doing a strictly E-LSA build. As a dumb pilot, I don't have the engineering or mx backgrounds to be getting that far off the path!

Missed Facebook comments - I wonder if an early builder who is approaching an overhaul decision in a few years could convince ROTAX to do an exchange for an IS to be a pathfinder on this issue and still maintain E-LSA status or not?

The fadec aftermarket options are interesting too.
 
- I wonder if an early builder who is approaching an overhaul decision in a few years could convince ROTAX to do an exchange for an IS to be a pathfinder on this issue and still maintain E-LSA status or not?

Very interesting question, could someone with E-LSA certification expertise provide an answer? As for the exchange by Rotax it's another story, too early to have Rotax making any commitment.
 
As long as the modification does not take the aircraft out of LSA parameters, it would not affect E-LSA certification.
 
Form 8130-15 is required to register the RV-12 as an E-LSA. This form must be obtained from VansAircraft. They will not give you form 8130-15 unless the complete kit is purchased from them and the following statement is signed:
I certify that I have received a complete RV-12 E-LSA kit from Van?s Aircraft, Inc. No components have been deleted, returned or altered. The aircraft will be assembled in accordance with Van?s building instructions.
http://www.vansaircraft.com/pdf/order_forms/RV-12/RV-12-powerplant.pdf
Therefore, if it is desired to register as E-LSA, the RV-12 must be built exactly according to the plans using the Van's supplied engine. Even if a builder perjured himself by signing a false statement in order to fraudulently obtain form 8130-15, a DAR would not approve a substitute engine.
After the aircraft receives its airworthiness certificate, changes may be made as Mel has stated. The engine can then be modified or replaced.
Joe Gores
 
I believe the question was about an aircraft that has been flying and is due for overhaul. That's why I answered as I did.

Of course to certificate as E-LSA originally, the aircraft must be built in accordance with the plans.
 
I believe the question was about an aircraft that has been flying and is due for overhaul. That's why I answered as I did.

Of course to certificate as E-LSA originally, the aircraft must be built in accordance with the plans.

That is correct....an airplane that has been certified E-LSA by Van's and the FAA, and flying for 5-10 years as an E-LSA....my guess is the first guys hit engine overhaul decisions in 3-4 years depending how much and how hard they are flying them. I think I saw a few are over 400-500 hours already.

Seems like it would be advantageous to Rotax to make it possible for the owner of a 912 to option for the IS....just like lycoming does with some their models.
 
Check with Don at http://www.airflowperformance.com, he came out with a fuel injection system for the 912 a few years back.

It was test flown on a Just Aircraft Highlander with good results.

I just checked their website and couldn't find it listed but they do sell it.
 
Advantages ?????

What are the advantages of the fuel injected 912 over the standard engine. Is it worth an extra $4000.00 and the cowling redesign.? I'm already experiencing 5.5 gal / hr. fuel burn and 120 - 122 kts TAS at typical cruising altitudes. I'm interested but curious about the net advantage for the effort and cost.

Jersey
 
Presumably you can run LOP and get longer engine life and better fuel economy?

The 912iS has a FADEC engine control system. I am pretty sure all the pilot can do is adjust the throttle position, the FADEC system (full authority digital engine control) makes all other control decisions after that.
 
912iS

What are the advantages of the fuel injected 912 over the standard engine. Is it worth an extra $4000.00 and the cowling redesign.? I'm already experiencing 5.5 gal / hr. fuel burn and 120 - 122 kts TAS at typical cruising altitudes. I'm interested but curious about the net advantage for the effort and cost.

Jersey

I belive they have a Lower fuel burn for same power output ..Plus No Induction ( Carby ) Iceing & No ongoing Carby Balancing...
 
The 912iS has a FADEC engine control system. I am pretty sure all the pilot can do is adjust the throttle position, the FADEC system (full authority digital engine control) makes all other control decisions after that.

sure, but presumably the FADEC has at least best-economy (LOP) and best-power modes.
regardless of how the control is done, my point is that fuel injection adds more flexibility in mixture setting than a carburetor.
 
sure, but presumably the FADEC has at least best-economy (LOP) and best-power modes.
regardless of how the control is done, my point is that fuel injection adds more flexibility in mixture setting than a carburetor.

Sorry, I didn't read your post that way.
Since you wrote "Presumably you can run LOP"
My point was, in reality you can't do anything to run it lean of peak.
Only the FADEC computer can, and I have not read anything that says it does. Only that they claim an improvement in fuel economy. That may be just from the fact that the mixture is better controlled through the entire power band, instead of just three phases of mixture as the carbs do now.
 
The factory Rotax FADEC is very sophisticated and therefore expensive, given the development and testing behind it. I am not sure if they run LOP.

In our testing with the Bing carbs, they were very well matched to the engine. The average AFRs (measured with a wideband AFR meter) were quite precise in almost all ranges, a little rich around 4500 if I recall. I was frankly surprised at how well they worked. The bigger problem was cylinder to cylinder mixture variation, clearly two cylinders run richer than the other two from EGT and plug color. With EFI, the EGT spread was dramatically less.

At WOT, the carbs showed a slight pressure drop. The larger EFI throttle plate we used and plenum manifold showed no loss in MAP at 5800 rpm so between these two things, the engine picked up 3-5 hp (80 hp test engine). Further independent testing showed fuel flows were about the same amount lower at the same hp. So the gains were small but useful with our system.

In testing the factory ignition, again Rotax engineers got it right. We saw no gains in hp using our programmable ignition however at higher altitudes, there would likely be some gains by advancing timing.

You can see some photos of the testing here: http://www.sdsefi.com/rotax2.htm
 
FADEC

sure, but presumably the FADEC has at least best-economy (LOP) and best-power modes.
regardless of how the control is done, my point is that fuel injection adds more flexibility in mixture setting than a carburetor.

The FADEC is set by Rotax in the factory to Give the best F/A Ratio at any Air or Engine Temp or Altitude so Only throttle movements are made by the pilot.... Timing & Mixture is all Automatic...!
 
Back
Top