Rotax 912 iS Sport instead of the 912 ULS?

[epaslick]

I have a question you RV-12 E-AB builders. Has anyone considered installing the Rotax 912 iS Sport instead of the 912 ULS? How much would have to be changed to make the iS Sport fit and how much added difficulty would that cause?

[Jetguy]

Originally Posted by epaslick

I have a question you RV-12 E-AB builders. Has anyone considered installing the Rotax 912 iS Sport instead of the 912 ULS? How much would have to be changed to make the iS Sport fit and how much added difficulty would that cause?

Yes! If you are a first time builder it would be very difficult.
Fuel system would be different.
Weight & balanced would be different.
Empty weight would be higher.
Cost of engine about $4000 more.
Cowl would be different.
Electronics would be different.
Increase build time by about 500 hours.
Etc, etc.

[waterboy2110]

I would also think there may be some wiring and configurations in the Skyview that would need to be taken care of. From what I recall from about reading - the IS has some upgrades available just to get it to the power of the ULS so what's the point unless you just can't stand the idea of a carb(s). I think the turbo Rotax is about 30lb heavier.

From my morning read in KitPlane changing out engines on a designed platform is not for the faint of heart. The article stated that insurance would be an issue and that the fly off would increase (the article eluded to a 25 hour eab if not to many deviations to a 40 if you change the PP - I've read about the FAA being liberal with fly off periods but have no experience with it... yet).

[epaslick]

My apologies, I didn't phrase my question very well, my fault. I was wondering if anyone else had looked into it and had specific details about what had to be changed and what could be kept from Van's...

Originally Posted by Jetguy

Yes! If you are a first time builder it would be very difficult.
Fuel system would be different.
Weight & balanced would be different.
Empty weight would be higher.
Cost of engine about $4000 more.
Cowl would be different.
Electronics would be different.
Increase build time by about 500 hours.
Etc, etc.

Any more difficult then building a 7 or 8 or 9 and choosing a non-Van's engine?

Originally Posted by Jetguy

Fuel system would be different.

Different lines firewall forward for the fuel injection I would expect, but would you need to change anything aft of the firewall? What about fuel pumps?

Originally Posted by Jetguy

Empty weight would be higher.

If the info on the Rotax website is accurate and I did my mental math correctly, the iS Sport would add about 15 lbs.

Originally Posted by Jetguy

Weight & balanced would be different.

See above.

Originally Posted by Jetguy

Cost of engine about $4000 more.

Van's powerplant kit for the RV-12 is currently $28,738.00 plus s/h. I don't know what they include in the kit though, as I haven't seen a breakdown. So I don't know the cost of any of the extras I'd need. I've seen adverts for the barebones ULS as low as $16,000.00, and as high as $22,000.00. The only price I've seen for the iS Sport so far is $23,918.00.

Originally Posted by Jetguy

Cowl would be different.

Yes, I would expect to have to mod the cowls. I would also expect the baffles to be different as well.

Originally Posted by Jetguy

Electronics would be different.

I would expect additional wiring for the engine management system.

Originally Posted by Jetguy

Increase build time by about 500 hours.

I've read on the forums that there are RV-12s with Vikings and Jabirus. I'm guessing that's the amount of additional time it took those builders to mod their RVs...

[epaslick]

Originally Posted by waterboy2110

I would also think there may be some wiring and configurations in the Skyview that would need to be taken care of.

So I would expect.

Originally Posted by waterboy2110

From what I recall from about reading - the IS has some upgrades available just to get it to the power of the ULS so what's the point unless you just can't stand the idea of a carb(s).

That is not my understanding. The difference is both the fuel injection and the engine management system to increase fuel economy. I haven't seen anything that says they had to mod the engine to increase hp.

And it's not so much that I don't like carbs, but I really don't like dual carb setups. I've had bikes with both 2 and 4 carb systems and they have never been anything but trouble for me.

Originally Posted by waterboy2110

I think the turbo Rotax is about 30lb heavier.

The iS Sport is not a turbo engine. It is approximately 15 lbs heavier than the ULS.

Originally Posted by waterboy2110

From my morning read in KitPlane changing out engines on a designed platform is not for the faint of heart. The article stated that insurance would be an issue and that the fly off would increase (the article eluded to a 25 hour eab if not to many deviations to a 40 if you change the PP - I've read about the FAA being liberal with fly off periods but have no experience with it... yet).

I believe 40 is the most common E-AB phase 1 time.

[bhassel]

I too have been wondering about the 912IS Sport. I think I read somewhere that Cato was developing a prop (the one's I've seen are works of art) that would offset some of that weight difference.

The additional fuel savings would sure stretch that 20 gallon tank!

Bob

[Mel]

Originally Posted by waterboy2110

(the article eluded to a 25 hour eab if not to many deviations to a 40 if you change the PP - I've read about the FAA being liberal with fly off periods but have no experience with it... yet).

FAA rules state that the minimum phase I flight test period is 40 hrs. for a non-certificated engine/propeller combination installed on an Experimental Amateur-Built aircraft. If anyone give less, they are violating the rules.

[Gagarin737]

Nice movie from Rotax-Owner about installation of a 912IS in a CH750 and with that the redesign of the fuel system -> YouTube

[waterboy2110]

Ah - my comment about the upgrade was to get the IS to the sport version. New mapping and air box I believe. Sorry about that.

Mel - I'm pretty sure the USL is not a certificated engine. My understanding is that's quite a bit more money. What gives? For ELSA is the rule ignored?

[Mel]

Originally Posted by waterboy2110

Ah - my comment about the upgrade was to get the IS to the sport version. New mapping and air box I believe. Sorry about that.
Mel - I'm pretty sure the USL is not a certificated engine. My understanding is that's quite a bit more money. What gives? For ELSA is the rule ignored?

The 912 ULS is not a certificated engine. Phase I test period should be a minimum of 40 hrs. for EAB.

For ELSA the rule is different. Phase I flight test for ELSA is 5 hrs. min.