New Rotax 915is trubo fuel injected 135 hp

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zaitcev
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Re: New Rotax 915is trubo fuel injected 135 hp

Postby zaitcev » Fri Jul 31, 2015 3:03 pm

Here's a video of a gyroplane with Rotax 912ULS taking off at a local field:
https://www.youtube.com/watch?v=1mNfoKhNSoY

It's not looking like them zooming at Sun-n-Fun, and that's with only 1 pilot onboard.

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Re: New Rotax 915is trubo fuel injected 135 hp

Postby Flocker » Thu Dec 24, 2015 8:42 am

drseti wrote:When I did my most recent Rotax Heavy Maint renewal with Eric Tucker in January, we discussed both the 914 and the 912iS.


What are your thoughts on the 912is vs. 914 debate?

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Re: New Rotax 915is trubo fuel injected 135 hp

Postby drseti » Thu Dec 24, 2015 9:52 am

There's no debate there. If you live in a mountainous area or consistently fly at or above 10,000 feet, the turbo is the way to go. For us flatlanders, it's unnecessary, and hard to justify the extra cost and maintenance expenses.
The opinions posted are those of one CFI, and do not necessarily represent the FAA or its lawyers.
Prof. H. Paul Shuch, Ph.D., CFII, LSRM-A/GL/WS/PPC, iRMT
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Re: New Rotax 915is trubo fuel injected 135 hp

Postby Flocker » Thu Dec 24, 2015 10:30 am

drseti wrote:For us flatlanders, it's unnecessary, and hard to justify the extra cost and maintenance expenses.


What is the (approx. ) difference in maintenance costs?

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Re: New Rotax 915is trubo fuel injected 135 hp

Postby MrMorden » Thu Dec 24, 2015 12:26 pm

Flocker wrote:
drseti wrote:For us flatlanders, it's unnecessary, and hard to justify the extra cost and maintenance expenses.


What is the (approx. ) difference in maintenance costs?


A friend of mine had a 914 powered Highlander. He sold it and bought a 912ULS powered airplane of the same type. He said the maintenance on the 914 engine was more complicated and expensive, and the extra power is only available for five minutes at a time, similar to the 5500-5800rpm band on the 912ULS. He said it was nice on takeoff, but just dead weight and extra expense at all other times.

The 915iS looks better because it makes continuous use of the turbo, or at least doesn't have a time limit on the extra horsies.
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Re: New Rotax 915is trubo fuel injected 135 hp

Postby Mark Gregor » Thu Dec 24, 2015 9:48 pm

The 912ULS and the 912is are both fine and very adequate engines but the 914 is in a different league and it should be considering the cost.

I have heard this debated many times and its almost always by pilots who have no time behind a 914. I can sum it up quickly by saying that a very high percentage of buyers choose the 914 after flying the 912 and 914 back to back in the same airframe. If there was little difference they would not spend the extra money. There is a substantial difference. If anyone wants to see for themselves I would be happy to give a test flight in the same airframe with the different engines. Just come to Minnesota anytime and we will go for a ride!

From a sales standpoint it makes no difference to us which engine you choose. Its just that the 914 is a lot nicer to fly behind.

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Re: New Rotax 915is trubo fuel injected 135 hp

Postby Flocker » Sun Dec 27, 2015 9:00 am

MrMorden wrote:A friend of mine had a 914 powered Highlander.... He said the maintenance on the 914 engine was more complicated and expensive...


Hundreds or thousands more expensive?

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Re: New Rotax 915is trubo fuel injected 135 hp

Postby FastEddieB » Sun Dec 27, 2015 12:04 pm

I was in Duluth for the announcement of the Tornado Alley Turbo-Normalized SR22.

Seemed like almost a free lunch - engine never stressed more than a normally aspirated one, just power held up to a much higher altitude with accompanying efficiency and TAS.

It only took a few years for owners to start seeing definite costs involved, with all sorts of failures of the installation, both large and small. Even sans failures, even routine maintenance and inspection was more time consuming and hence, more expensive.

If I had to WAG, I'd say maybe a 20% increase in maintenance costs. And very possibly still worth it to owners.

May or may not apply to the boosted ROTAX. But the saying about no free lunch does come to mind.

Still, like in the case of the Cirrus, it might still be worth it.
Fast Eddie B.
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Re: New Rotax 915is trubo fuel injected 135 hp

Postby drseti » Sun Dec 27, 2015 12:14 pm

I can't give you any hard and fast numbers, since I don't maintain any 914s, but just in terms of the annual inspection, the Turbo will add about 2 to 3 hours of labor (that's a 20 to 30% increase). Roger Lee can probably speak to his experience.
The opinions posted are those of one CFI, and do not necessarily represent the FAA or its lawyers.
Prof. H. Paul Shuch, Ph.D., CFII, LSRM-A/GL/WS/PPC, iRMT
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Re: New Rotax 915is trubo fuel injected 135 hp

Postby SportPilot » Sun Dec 27, 2015 5:51 pm

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Last edited by SportPilot on Sun Mar 20, 2016 6:07 pm, edited 1 time in total.

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Re: New Rotax 915is trubo fuel injected 135 hp

Postby Mark Gregor » Sat Jan 02, 2016 8:35 pm

The Rotax 914 turbocharged really should not be compared to a Lycoming or continental turbo normalized engine.
The 914 was designed for turbocharging from the beginning and has had many years to work out any bugs.

The design of the Rotax aircraft engine is also nearly 50 years newer. The engineering power Rotax has available is not really comparable. If Rotax decides they want to own the high horsepower piston aircraft market they could pretty much do it at any time. When you look at the total number of engines manufactured by Rotax and the many new designs they come out with every single year you will see that they can do pretty much what they want.

Tecnam tells us that when there is negativity toward the 914 it usually originates from a home built or one off installation. They tell us that although there are more moving parts they have not seen measurably less reliability from the 914 when compared to the 912. We have clearly seen more issues from the 912Is but after the updates it seems to be a good engine also.

Tecnam is the largest user of Rotax aircraft engines so they should know.

Mark

As far as additional maintenance costs of the 914 it is going to be more just because it has n more moving parts but based on our experience so far and what Tecnam is telling us I don't think it is a big issue.

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Re: New Rotax 915is trubo fuel injected 135 hp

Postby jetcat3 » Fri Dec 22, 2017 9:26 am

Hey y’all,

I’ve been pretty excited about this engine since it was announced two and a half years ago. It’s nice to see Rotax finally receive their type certificate for the engine! I thought this was particularly interesting. “Not only has the certification been achieved within the promised time schedule but the engine has been certified to even higher power than originally announced. Instead of 100kW (136hp) maximum power the engine will offer 104kW (141hp) maximum power instead and 99kW (135hp) maximum continuous power. Once more we will provide the ultimate flight experience to pilots.”

All 141 HP is available up to 15,000ft. Very impressive!

Another interesting thing I found was in the operators manual. They have the compression ratio listed as 8.2:1 for the 915 iS, whereas the 914 turbo is 9.0:1. The 912 ULS is 10.8:1. Any idea if that lower compression ratio will make the engine smoother? I have quite a bit of time behind the 914 turbo and 912 ULS and can say that the 914 is noticeably smoother but am not sure what all to contribute that to. Turbo, compression ratio, or a nice mixture of both? Thanks y’all.

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Re: New Rotax 915is trubo fuel injected 135 hp

Postby Warmi » Fri Dec 22, 2017 9:35 am

I was interested in 915is as well but ....look at the price: https://www.cps-parts.com/catalog/rtxpa ... ine140.php

Damn. That is more than twice as expensive as 912 ULS - combine that with +50 lbs penalty ... I don't know.
Flying Sting S4 ( N184WA ) out of Illinois

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CharlieTango
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Re: New Rotax 915is trubo fuel injected 135 hp

Postby CharlieTango » Fri Dec 22, 2017 9:44 am

Rotax has entered the flight levels

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Re: New Rotax 915is trubo fuel injected 135 hp

Postby Wm.Ince » Fri Dec 22, 2017 11:32 am

CharlieTango wrote:Rotax has entered the flight levels

Yeah . . . the price is out of this world.
Perhaps fitting for a new RANS S-21. But for that much money, you could probably install a 180hp Titan 340 . . . an awesome engine (standard equipment in the Carbon Cub!).
Bill Ince
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