Sport Engine report

[Olarry]

Picked up my plane yesterday from Lockwood Aviation after having it's first annual inspection and the installation of the sport engine upgrade.

My first impressions were I'm glad I had it done. As Roger stated in an earlier post, It's worth doing and I concure.

 

The climb out performance is a seat of the pants opinion but I can tell you it is significantly improved and verified by Phil Lockwood who test flew it and told me I will be impressed.

 

While never an issue, the engine smoothness and lack of vibration is even more evident. It also seems quieter than before. At idle, 1700 and above rpm's, All gearbox rattle and vibration has been eliminated.

 

I also had a slight static problem when listening to distant stations or controllers and this seems to have gone away. In reading the Rotax information regarding the upgrade, they stated an improvement in radio reception should be forthcoming as the "plug ins" have been improved.

 

Lockwood did repitch the prop slightly and since it's a short flight from Sebring back to Ft Myers, I don't know how cruise speeds have been affected. My opinion is "not much" but will post if I see a major change.

 

While not cheap and since all new Flight Design delivery's will come with the sport engine as I understand,

I would not hesitate to go with the upgrade if I had to do it all over again.

[FastEddieB]

Glad to see the new engine is evolving.

 

I predict it's going to be a big hit going forward, making a good engine already better.

 

Only drawback I still see other than the higher weight is the need for special training and equipment to do some troubleshooting and even routine stuff. Not a big deal if an appropriate dealer is nearby, more so I one isn't.

[Anticept]

30 pounds is a LOT of weight.... that's 5 gallons of gas.

 

By the way, there is no iS iRMT rating yet... they are still designing the course!

[FlyingMonkey]

That's just the Rotax baseline weight.  Actual difference depends on the installation particulars.  My understanding is the weight delta for a CT is 22lb.

[FlyingMonkey]

30 pounds is a LOT of weight.... that's 5 gallons of gas.

 

 

Once could argue that the fuel savings of the injected engine might offset the weight penalty, but that is very situation dependent.  At high altitude where you have to run WOT in cruise, the engine goes rich and those savings disappear.  Down low and at moderate engine rpm you probably would come out ahead.  But when you add in the ~$12k price difference, it starts becoming a harder choice to justify, IMO...$12k buys a lot of fuel.

[FlyingMonkey]

What are you talking about?  It's the delta weight between the two engines. There is no 'magical' unstated set of goodies that vary between the two engine installs.

 

 

So there is no additional equipment required to support the engine?  No dual batteries as you have said before?  No dual regulators?  No dual electrical bus paths and associated wiring ( Lane A / Lane B )?  Is all that stuff not included in the engine itself weightless?

 

The 22lb weight is what Roger Lee and others have reported previously.  I bet the Sport upgrade did not make it lighter, either...    

 

What are YOU talking about?

[Tom Baker]

The CTLSi installation requires a header tank for the fuel supply. In addition to the tank you have the more sophisticated fuel selector valve and additional plumbing. I also believe that the battery needs to be of a higher capacity than the standard CT battery. All of these items are in addition to the weight increase of the engine by Rotax.

[Farmer]

I have a CTLSi and I am woundering what would  happened if, as others on this site have reported, a dead short of the battery occurred in flight.  I know that there is a emergency battery connect switch on dash.  I know of two alternators, but what about a dead short?  Look at my spot track from last Sunday as I attended a flyin on Molokai, 30 mile of open ocean, at 2000 feet agl/msl,  just for fun.  Not looking for a debate on over water flying, it is a fact of life here.

 

Have a nice day

 

Farmer

[Tom Baker]

No. The header tank isn't required and the new selector valve are both FD redesigns of their fuel system - you get this header tank if you optionally select the 912ULS also. And the LeFi battery is lighter not heavier than the old one. 

 

Here is a video of a Kitfox 912iS install done on the spot at a tradeshow after a guy flew his Kitfox in and swapped it out in place = they even used the same prop!.  NO MODS to his plane other than the engine. 

 

Your video proves nothing. It talks about an airplane that came new with a 912iS, and was upgraded to the sport version at the show, and not a swap from a 912ULS to a 912iS.

 

The header tank and selector valve is something that was added specifically for the CTLSi. This is because of the fuel return from the fuel injection system. Without the changes to the fuel system it would be possible to dump fuel overboard. I don't know if all CT's now come with the header tank, but it was not available before the CTLSi.

 

As for the 22 pound weight figure it comes from the CTLS/CTLSi brochure on the Flight Design USA website. Here is the clip, " Cost is $12,800 more than CTLS at less than 22 lbs weight increase". It does say less than 22 pounds, so I suspect it is between 21 and 22 pounds. If the increase was less than that figure I am sure they would say so.

[FlyingMonkey]

BTW, every Kitfox has a header tank, it's part of the fuel system design.

[Tom Baker]

The discussion is about the engine.  Not the FD CTLSi.  FastEddie started this by complaining about the increased weight of the engine.

 

Even so, a 22 pound increase in weight is trivial.  The new engine is superior to the older carb'd version.  If you don't want a CTLSi with the added 15 pounds of engine weight then buy the plane with the 912ULS and not the 912iS.  No one else does that, but nothing stops anyone else from doing that.

The report was about the engine installed in a CTLSi, so I definitely see a tie in to the airplane.

 

I didn't take Fast Eddie's post as a complaint about the weight, but rather a simple and factual statement.

 

I'm just trying to set the facts straight, for others who might read this forum. Also I am trying to honor you request from post #8, by explaining the difference and showing you where to get the information.

 

BTW the reason no CTLSi are being shipped with the 912ULS is because the "i" indicates that the fuel injected engine is installed.

[FastEddieB]

I didn't take Fast Eddie's post as a complaint about the weight, but rather a simple and factual statement.

That's all it was meant to be.

 

I have owned planes with both carbureted and injected engines. On most scores, injected is better.

 

I would not be surprised to see ROTAX phase out their BING-carbed models. Nothing inherently wrong with their design, but anyone who's been around them knows their foibles - mainly float, float bowl and obstructed jet related.

 

As far as owning an injected ROTAX, I think the price delta would have to come down, and the weight penalty would have to make sense for a particular airframe. Bear in mind my Sky Arrow empty was 861 lbs. Take that to 883+ with an injected motor, and it would be even more of an operational hassle to stay legal.

[Anticept]

The header tank and selector valve is something that was added specifically for the CTLSi. This is because of the fuel return from the fuel injection system. Without the changes to the fuel system it would be possible to dump fuel overboard. I don't know if all CT's now come with the header tank, but it was not available before the CTLSi.

 

Hey Tom!

 

The big reason for the header tank is that the fuel injectors used on the iS is intolerant of air in the system. Air can cause engine stoppage in the iS. The design of the header tank as recommended by rotax is so that vapor can bubble up to the top and return to the wing tank, so in many installations, the line to the engine is at the bottom, and the fuel return is a little bit higher to prevent re-ingestion of any air. It's also why they chose the fuel circuit that they did; as the engine sits after a flight, the heat causes vapor in the lines, so the fuel pump purges the air immediately as you flip on pumps and start.

 

The funny thing is, rotax suggested a header tank for carbed engines too for the purpose of returning air to the tanks. But, the iS is much more sensitive to vapor, so it's basically a requirement!

[Tom Baker]

Hey Tom!

 

The big reason for the header tank is that the fuel injectors used on the iS is intolerant of air in the system. Air can cause engine stoppage in the iS. The design of the header tank as recommended by rotax is so that vapor can bubble up to the top and return to the wing tank, so in many installations, the line to the engine is at the bottom, and the fuel return is a little bit higher to prevent re-ingestion of any air. It's also why they chose the fuel circuit that they did; as the engine sits after a flight, the heat causes vapor in the lines, so the fuel pump purges the air immediately as you flip on pumps and start.

 

The funny thing is, rotax suggested a header tank for carbed engines too for the purpose of returning air to the tanks. But, the iS is much more sensitive to vapor, so it's basically a requirement!

That is not how it was explained to me when I did my Rotax recurrent training, but that answer works too.

[FastEddieB]

I did have an engine stoppage in my Cirrus at about 16,000' while switching tanks. Got it sorted out and it sprang right back to life.

 

I mention this because injected engines - in general - tend to start right up after a tank is run dry - no more nor less quickly than an equivalent carbureted version once fuel flow is restored.

 

Is there something peculiar to the 912iS that makes it less tolerant to fuel interruption?

[Anticept]

That is not how it was explained to me when I did my Rotax recurrent training, but that answer works too.

 

Of course, as a side effect, without the return line the pressure would be so high it really could dump fuel overboard

[Znurtdog]

You said;

"Lockwood did repitch the prop slightly and since it's a short flight from Sebring back to Ft Myers, I don't know how cruise speeds have been affected. My opinion is "not much" but will post if I see a major change."
 

I'm glad you're happy with the upgrade, but I do think that having the prop repitched at the same time as the other work, you can't be sure the changes are from the 'sport' and not the prop.