What's new
Van's Air Force

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

Jabiru RV-12 Update

KatieB

Well Known Member
The RV-12 at Jabiru USA is coming along nicely. Pete and the guys are almost done with the empennage kit already after just a few short weeks and the wings will be here soon.

RV12JabiruProject


We're hoping the lighter weight and better economy of the 85-hp 2200 will offset a slight loss of horsepower when compared with the Rotax. I can't wait to fly it. :cool:
 
jab 2200 Embracing simplicity

The RV-12 at Jabiru USA is coming along nicely. Pete and the guys are almost done with the empennage kit already after just a few short weeks and the wings will be here soon.

RV12JabiruProject


We're hoping the lighter weight and better economy of the 85-hp 2200 will offset a slight loss of horsepower when compared with the Rotax. I can't wait to fly it. :cool:

Katie
Thanks for the update

I think the 2200 will perform very close to the Rotax.
And you did not mention the cost savings of the jab engine .
Please keep us informed on the progress.

Building EAB lets you build the plane with all the alterations you want.
I’m using flush rivets on my 12 and I will use the Jab if it performs as I think it will.

What is the kit # of Pete’s 12 and what is he using for primer?

Thanks
 
Last edited:
Up Date

Katie,

Keep us updated on the progress. Also, what modifications have they done to the fire wall to accept the engine mount, who fabricated the engine mount, weight and balance challenges/calculations etc. This may be a good option to the Rotax which so far has not proven itself to be all that reliable, especially for the price paid.

Post pictures of the engine mounting details etc.

Thanks in advance,

Gary
 
Last edited:
Katie,

This may be a good option to the Rotax which so far has not proven itself to be all that reliable, especially for the price paid.

The Rotax (912) hasn't proven itself to be all that reliable?? Details, please.

The Jab should be an interesting option and glad to see it being explored.
 
jab reliability

not trying to knock jabs but look how many have to be rebuilt at 500 - 600 hours and look at how many have cylinder through bolts failing and valve gear failures
 
Oops!!!!!

Oops; I think I inserted a size 12 in my mouth. My dad once told me that the road to **** could be paved with good intentions.

I did however qualify my statement with "especially for the price paid".

You have to forgive my thought process at the moment since I just loss a fuel pump and oil pressure sensor on a cross country with just barely 44 hours on the tach. It's not a good feeling when your trying to get home, weather conditions are deteriating and your fuel consumption jumps to 7 gal / hour, you smell gas and then a few minutes later the low oil pressure alarm goes off. Oh, and also two of my engine mounting bolts nearly rattled out after 32 hours. I know this does not reflect reliability since the engine continued to operate but after plopping down over $24,000.00 on engine I would have hoped that these issues would have been resolved during testing etc. We have a fairly large group of builders in my area that rarely have any problems with their new Lyc. engines.

Then there's the issue where I just found out I need to purchase a soft start kit so the slipper clutch doesn't get damaged.:eek:

I know that my statements are subjective due to my personel experience and doesn't account for thousands of 912's out there that continue to operate flawlessly but as requested "those are the details". Again remember that I qualified my statement with "especially for the price paid".

I know I have again opened myself up for a severe flogging but truly just wanted to encourage the Jab folks in their endevours and am curious about their project.

I will continue to check my mounting bolts every 25 hours, relocate a new oil pressure sender to the fire wall, and purchase and install a soft start kit. I just hope thats the end of the minor issues that I experienced because I love the way the 12 performs.

Please only use wet noodles during my flogging. :eek:

With good intentions,

Gary
 
Just because they didnt say it doesnt make it so!

Gary, I feel your pain. But we are flying an “Experimental airplane”.:rolleyes: The RV12 is new to the market place. It is going to incur problems. Yeah there are plenty of Rotaxs out there. But not as many as Lycs and Conts which have been around for 60 years. And yes they built new engines that had problems right out of the box. Just go look at all the ADs out on them. Do you think that the first builders of the first RV 4s, 6s, 7s, 8s, 9s, & 10s didn’t encounter problems!:eek: Whenever you are on the tip of new technology you encounter unknown problems. The builder cant plan plan for every contingency.:eek: The RV12 and the Rotax as installed are new technology! As a group we are seeing these problems as they occur and we are fixing them. We are all still Virgins when it comes to this plane. If you read about a problem on the form use your own powers of deduction and see if a change on your plane is required. We had a big discussion about moving the Oil pressure sending unit to the firewall and the reasons why.:confused: Did you blue loctite those cap screws? ;)The reality is we are not going to get much support from Rotax or Vans on these issues. We are just going to have to figure them out ourselves and share the results on the form so other guys will have it easier. Here is a quote I received from another RV12 owner on Rotax, "You vill doo tings OUR vay’! Mounting that Oil Pressure sender on the front of the engine is wrong, but Rotax is not going to change it. But as builders we can apply common since and make a change for a better set up. Just because Vans or Rotax doenst say to change something it doesn’t mean we shouldn’t. Now, not to pry but have you done everything you can to reduce vibration from you propeller?:)We will encounter more problems and we will solve them. Now bend over and take you noodle whipping like a Man.:eek:

PS Don't take this reply as a noodle whipping just keep pushing ahead buddy.
 
Last edited:
The RV12 and the Rotax as installed are new technology! .... Mounting that Oil Pressure sender on the front of the engine is wrong, but Rotax is not going to change it. But as builders we can apply common since and make a change for a better set up.

One of my 912 mechanics says all the time that the only true enemy of the Rotax is its owner/operator. And I think he's exactly right about that since, when left alone and installed/operated the way Rotax specifies, it gives no trouble. Also, the 912 series is NOT new technology anymore; in fact, it's one of the highest selling engines of all time now and has one of the best reliability records you can find in an aircraft engine.

So, all that said, there's nothing wrong with the location of the oil pressure sensor as-is - the engine will go to TBO and beyond giving no trouble with the sensor right where it is, so I'd suggest leaving it alone for reliability and long life and following the manuals to the letter.

I would also suggest that Vans knew what they were doing when they made the few alterations to the motor that they have, so it's probably a good idea to give their methods a chance before substituting them for you own.

Not an RV12 builder, just a very satisfied long-term Rotax user,

LS
 
Rotex Engines

I am not sure you can compare the Rotex 912 and Rotex 914 regarding realibility but the Air Force pulls the Rotex 914 off the preditors for return to the factory for overhaul after I believe 365 TT. A engine, even one that flys for 20+ hours at a time, that a user feels needs factory overhaul after 365 hours TT on a system wide fleet of the entire Air Force says something.
 
[ed. political sentence removed. dr]

Unfortunately you also deleted the statement about budget, which is relevant to the comparison. Namely, we have to pay much more close attention to both purchase price and long-term costs when choosing an engine than the other entity does. For it's TBO and reliability record the 912 series are about the best buy you can get, but the 914 is a bit higher cost.

As for the Jab., I'm gratified to see it starting to gain traction and would love to see it in the RV-12. I'm sure it'd make a great combo!

LS
 
Last edited:
Jabiru update or Rotax bashing?

This thread was supposed to be about the Jabiru RV-12 update, not Rotax (and even less Rotex).
 
This thread was supposed to be about the Jabiru RV-12 update, not Rotax (and even less Rotex).

Jean-Pierre

I think this is about the Jab update
The Rotax is the RV 12 Engine

The jab is a substitute for the Rotax
The points made on this thread are all welcome

The two choices talked about help us make up our mind.

I Think the jab may be a good substitute for some builders wear cost is of concern.

My Two Cents
Thanks
 
I am not sure you can compare the Rotex 912 and Rotex 914 regarding realibility but the Air Force pulls the Rotex 914 off the preditors for return to the factory for overhaul after I believe 365 TT. A engine, even one that flys for 20+ hours at a time, that a user feels needs factory overhaul after 365 hours TT on a system wide fleet of the entire Air Force says something.

How often do F1 racing car engines get replaced ? There is a world of difference between the "mission" of a 914 in a Predator and a 912 in an RV-12. Not to mention the available cash to hand to refurb "Preditor" 914s. Lets try and compare apples with apples.
 
Owners worst enemy

In response to "the owner is the 912's worst enemy".

Perspective: As an owner and operator of the aircraft.

Both the fuel pump and the oil pressure switch were factory installed. I didn't install them or modify them; all I did was install the engine as shipped. In addition, there are no Rotax instructions as to maintenance and operation of these items to keep them from failing. My comments were based and qualified on my personal experience with these failures.

Please explain how these failures could have been prevented if I was a good owner and not it's worst enemy. In addition how can I be the 912's worst enemy by needing to install a soft start kit. :rolleyes:


Gary
 
Last edited:
In response to "the owner is the 912's worst enemy".

As an owner and operator of the aircraft. Both the fuel pump and the oil pressure switch were factory installed. I had nothing to do with the failure. In addition, there are no Rotax instructions as to maintenance and operation of these items. Please explain how these failures could have been prevented if I was a good owner.:)

Gary

Sorry, Gary, I was addressing Jetguy's suggestion that these be changed. I didn't mean to impugn you. My apologies if it came across that way ;)

LS
 
Oops

Sorry Lucien,

I was changing my post when you responded.

My sincere apologies. :eek:

Been a long day

Gary
 
Gota love those Pusher Guys!

Lucien, This form is very unique. Its about information on a plane of which 95% are built exactly the same way. All Vans E-LSAs have to be built exactly the same to receive their Airworthiness certificate. There are approximately 72 flying. Not all owners are on the form but most are. So when guys have problems they usually report them here.:eek: I would say that at least 5 guys have had the Honeywell oil pressure sender fail on their RV12s. This sender comes installed on the engine when it comes out of the box. Why do you think that has happen?:confused: If you google Rotax 912 oil pressure sender failure you get a whole page of hits. Why do you suppose those failed? Throughout history manufactures have released products that are very well made but have had some little problem that goes bad over and over again. For whatever reason they just refused to fix that problem. Lockwood Aviation, one of the largest Rotax dealers in the USA, actually has a part number for a kit that they created on their own, to better support their customers. This kit is used to relocate the sender to the firewall. Why do you suppose they decided to create and sell this kit? Feel free to read my post at this link:
http://www.vansairforce.com/communit...t=64145&page=2
Look for my thread posted 11-13-2010, 06:13 PM on the above link. The Honeywell unit cost $300 unlike the old VDO unit which cost $45. Which do you have on your Pusher? I simply researched the problem and used some common sense, then came up with a solution so I wouldn?t have to spend $300 every so often. I then shared this info on the form for others to read and decide on their own if they think they should make the change.:D
The RV12 was released for sale to the public April 2008. Although the Rotax 912ULS is not new technology however the installation on the RV12 is basically new. Vans cannot plan for every eventuality but as they gain more experience they may or may not make changes. We live in the land of Lawyers so every manufacture is very careful about what they do or say about their products. As I said before Rotax has many Service Bulletins as well as ADs about their engines just like everybody else. As good as it is there maybe some small room for improvement to the RV12 owner to make it work better and save some money along the way. I'm glad yours works perfectly, mine didn?t so I fixed it. Maybe my prop is different than yours and caused more vibration. Maybe the air flowing through my cowl caused the wire to the sender to vibrate. Maybe my 912 is a lot newer than yours and it has some slightly different harmonic vibration. Who knows. When do you plan to start on a RV12 so we can compare more exact notes? :)
 
Jetguy is right

I too am installing the relocation kit for the $300 Honeywell sensor before it gets beat to death. They do indeed have a high failure rate as do the fuel pumps located directly above them. Next to the gear box cannot be the best place for precision instruments. Rotax is the manufacturer of the engine and they know best. That is why all of the new engines have soft start modules. I cannot afford $2000 worth of new modules so I will move some the instrumentation to a "softer" location. John has done it already and it works great. But then ours our experimental not SLSA. But then thats why we built one instead of buying one. Thanks again John.
 
Thread Drif

Thread Drift


Jean-Pierre

On second though I think you are right


Katie we need a update
 
Last edited:
Lucien, This form is very unique. Its about information on a plane of which 95% are built exactly the same way. All Vans E-LSAs have to be built exactly the same to receive their Airworthiness certificate. There are approximately 72 flying. Not all owners are on the form but most are. So when guys have problems they usually report them here.:eek: I would say that at least 5 guys have had the Honeywell oil pressure sender fail on their RV12s. This sender comes installed on the engine when it comes out of the box. Why do you think that has happen?:confused: If you google Rotax 912 oil pressure sender failure you get a whole page of hits. Why do you suppose those failed? Throughout history manufactures have released products that are very well made but have had some little problem that goes bad over and over again. For whatever reason they just refused to fix that problem. Lockwood Aviation, one of the largest Rotax dealers in the USA, actually has a part number for a kit that they created on their own, to better support their customers. This kit is used to relocate the sender to the firewall. Why do you suppose they decided to create and sell this kit? Feel free to read my post at this link:
http://www.vansairforce.com/communit...t=64145&page=2
Look for my thread posted 11-13-2010, 06:13 PM on the above link. The Honeywell unit cost $300 unlike the old VDO unit which cost $45. Which do you have on your Pusher? I simply researched the problem and used some common sense, then came up with a solution so I wouldn’t have to spend $300 every so often. I then shared this info on the form for others to read and decide on their own if they think they should make the change.:D
The RV12 was released for sale to the public April 2008. Although the Rotax 912ULS is not new technology however the installation on the RV12 is basically new. Vans cannot plan for every eventuality but as they gain more experience they may or may not make changes. We live in the land of Lawyers so every manufacture is very careful about what they do or say about their products. As I said before Rotax has many Service Bulletins as well as ADs about their engines just like everybody else. As good as it is there maybe some small room for improvement to the RV12 owner to make it work better and save some money along the way. I'm glad yours works perfectly, mine didn’t so I fixed it. Maybe my prop is different than yours and caused more vibration. Maybe the air flowing through my cowl caused the wire to the sender to vibrate. Maybe my 912 is a lot newer than yours and it has some slightly different harmonic vibration. Who knows. When do you plan to start on a RV12 so we can compare more exact notes? :)

Perhaps I should also add the proviso that I was talking about arbitrary or untested changes, not changes required by the airframe manufacturer. So I also didn't mean to impugn your changing something that Vans or even Rotax says you should change ;).

That cleared up, my 912ULS (made in 2005) has the original Rotax OP sender on it and, at a little over 400 hours, it's finally starting to read a little low. It still works, tho, and I don't dare pull the thing out until it just slap quits working.

But I agree with you on the sensor and the general quality of some of the accessories. The OP sender seems to fail fairly commonly at some point in the life of the engine. In fact, the 912 series usually outlasts a lot of the accessories on it like the sender and the carbs (which have to be rebuilt several times over its life). The fuel pump is supposed to go all the way to TBO, tho I've also heard of occasional failures with it too.

But Rotax is actually pretty sensitive about flight-critical components. In fact, if you call Lockwood for a replacement fuel pump, they'll give you the third degree on the one you're trying to replace it with and ask you to send it back to them so they can show it to Rotax.

Apart from all that, the engine is best left alone and installed/operated by the manuals. I know of one gentleman who's on his 3rd 912 on the same airframe - he basically takes them out of the box, bolts them to the plane and goes flying. He replaces then at TBO and from his reports the engines are usually still running perfectly when he takes them off. He doesn't fiddle with it and I think that's how he gets those kinds of results.

As for the RV12, I got a fist full o' lottery tickets right here, which will hopefully buy me my kit one day ;). It looks like it's turning out to be a great plane, can't wait to get mine ;).

LS
 
Jabiru Update!!

Keep us updated on the progress. Also, what modifications have they done to the fire wall to accept the engine mount, who fabricated the engine mount, weight and balance challenges/calculations etc.

Just as we've done with many kit designs in the past, we're offering the Jabiru firewall forward kit as a choice for builders who prefer a simple, economical engine alternative.

We're currently building the fuselage of our RV-12 kit. The real "meat" of the engine installation will happen probably in the next month or so, and I'll be sure to keep the thread updated when that happens. Right now, it's just the everyday RV-12 you all have seen on VAF and in person.

The initial testing will be done with the 2200, which is small enough to allow plenty of room for the stock firewall. We do not anticipate the need for any airframe mods for the 2200. The engine mount is welded to our specifications by our supplier here in the U.S. and will come with the firewall-forward kit, along with fiberglass cowling, Sensenich prop, spinner, oil cooler, and a variety of other equipment and accessories. We'll know more as we progress with the installation and testing on our own airplane.

We're not anticipating any weight and balance challenges with the 2200. The 2200 mount will be extended a few inches to make up for the lighter engine. Van's weight and balance limits and max gross weight of the airframe will not change.

The 85-hp 2200 will be tested first so we get a good idea of the head-to-head competition with the Rotax. Yes, there is a slight loss of takeoff horsepower, but there is also a reduction in weight. Based on other Rotax-powered aircraft designs we've tested, we anticipate a slight loss in climb performance but similar cruise. The 2200 will be a good engine option for people who are willing to trade a little performance for a simpler, more economical engine.

Currently the 2200 costs $14,500 complete. The firewall forward kit should cost about $3700. Of course there are always pilots clamoring for more power, so the 120-hp 3300 will probably follow the test phase with the 2200. We had great success with the 3300 in the Rans S-19, which has a heavier empty weight than the RV-12.

I'm not sure when it will fly, but you'll hear about it first on VAF. :D

Katie Bosman
Jabiru USA Sport Aircraft, LLC
 
Last edited:
Jab Update

Katie
Thanks for the Update

I will hold off ordering my finish kit until Pete has a list of items to delete from the order. I sure the credit will not be the same as the cost to replace them, but the credit will offset the price of your finish kit. I talked to Pete last week add he said he will try to have the 12 at Sun-Fun before it is certified for flight.
I sure this will be a good choice for some builders.
And me.
Thanks again
 
What about E-LSA certification with Jabiru 2200?

Although I like the current Rotax motorization on the -12, it would not hurt to have the Jabiru as an additional option but I wonder what amount of R&D is involved either for VANs or for a third party to get there. I think that for the builder of the two existing S-LSAs getting the Jabiru certified would involve much less work/costs/time than for a third party. Indeed VANs is already ASTM certified for the airframe, therefore I would expect VANs to be open to the idea but what do I know? As a low time pilot and inexperienced builder, I believe there is great value in the E-LSA concept and it would be in the interest of the LSA builders community to have more E-LSA options.
 
Jab.

Hi Katie,

Thanks for all the development work you guys are doing on the Jab. engine Installation. I'll keep an eye on the outcomes of both the 2200 & 3300 installations in the RV. Im not a builder as yet but keeping a close lookout for alternative solutions to price & performance! The Jabiru Factory is only 80 miles from me here so Fingers crossed! Thanks once again.!

John H.:)
 
Jabiru Update

We have the forward fuselage looking like a plane-shaped canoe now. The first engine mount will be here in the next several days so we can plan where things will go on the firewall. If this week goes as planned, the forward fuselage will go to Wisconsin on Superbowl Sunday so our fiberglass guys can work on shaping the cowling next week. Pete should have good driving conditions in Wisconsin on Sunday, with the blizzard over and the Cheeseheads all safely in front of their TVs. :D

Will post more pics as things shape up later this week. Thanks for all the messages and calls with questions & support!
 
We have the forward fuselage looking like a plane-shaped canoe now. The first engine mount will be here in the next several days so we can plan where things will go on the firewall. If this week goes as planned, the forward fuselage will go to Wisconsin on Superbowl Sunday so our fiberglass guys can work on shaping the cowling next week. Pete should have good driving conditions in Wisconsin on Sunday, with the blizzard over and the Cheeseheads all safely in front of their TVs. :D

Will post more pics as things shape up later this week. Thanks for all the messages and calls with questions & support!

Katie, my primary interest is in the 3300. Has your company looked at the 3300/RV-12 combination enough yet to know if it is a viable option?
 
Jabiru

If you read ALL the posts on this Subject you will see what developments are in hand and Furture Proposals .......THANKS..!
 
If you read ALL the posts on this Subject you will see what developments are in hand and Furture Proposals .......THANKS..!

I have read the posts. The only reference I see is Katie's last statement of: "Of course there are always pilots clamoring for more power, so the 120-hp 3300 will probably follow the test phase with the 2200".

"Probably" doesn't say much. I am just asking for a little clarification. Will the 3300 work, given the overall length and that effect on weight and balance? Can it be set back enough in relation to the firewall to be made to work? Has Jabiru USA looked at these issues? Or will this be done at a later date?
 
3300 is planned...

but not for several months, til after the airplane flies at least 50-100 hours with the 2200. We'll learn a lot about weight and balance, cooling, instrumentation, etc, then use that data to proceed with the 3300. If the 3300 proves to be too big and impractical, or requires hacking up too much of the beautifully-engineered Van's kit, then we won't offer it as a firewall forward kit. It is pretty big to stuff into the space we have, given the L-shaped firewall.

It weighs a little more than the flying 912ULS as installed in the prototype RV-12, and it's shaped differently, which will probably require moving it forward a few inches. That was not an issue with the Rans S-19, which has a flat firewall, but the -12 is more of a challenge. We do know that the 3300 as installed in the S-19 did not cause a nose heavy airplane, despite being moved forward a small amount-- in fact, it was right on the Rans figures for empty CG. Other items such as cowl, spinner, prop, battery location, and even avionics, play a part also. Hopefully it will be no different than the typical scenario of a traditional RV with a constant-speed prop or bigger engine.

We would love to offer the 3300, and we will if it's practical. We will know much more by Oshkosh.

Thanks!
Katie
Jabiru USA
 
Last edited:
Has anyone heard the "skinny" on these engines? Cosmetically they are beautiful. Is the motor any good? How many hours are users getting from them? If the innards are as good as the exterior appears to be, they should be pretty good but what is the story?
 
Has anyone heard the "skinny" on these engines? Cosmetically they are beautiful. Is the motor any good? How many hours are users getting from them? If the innards are as good as the exterior appears to be, they should be pretty good but what is the story?

Thank you Dave...I have wanted to ask that myself. What is the attraction that would make someone want to change the existing set-up? (I can understand Katie's...she sells em). But, are they cheaper?, longer TBO, better fuel burn?. It doesn't matter how fast they go. There are already several ways to make the existing 12 go faster if you want to risk making your plane a yard ornament.
 
A few facts...

Jabiru engines are direct-drive and air-cooled. No gearbox, no coolant.
The 4-cylinder 2200 weighs 141 lbs and puts out 85 hp.
The 6-cylinder 3300 weighs 180 lbs (flying weight) and puts out 120 hp.
Cruise RPM is usually 2850-2950 rpm.
A 2200 and complete firewall-forward kit from Jabiru USA for the RV-12 will cost about $19,000 and include a Sensenich prop, spinner, cowlings, engine mount, oil cooler, and more.
Any A&P or the builder of the aircraft can work on them.
They can burn 100LL or high-octane auto fuel.
Average fuel burn on the 2200 is about 4 gph.
TBO is 2,000 hours.
Dual transistorized magneto ignition
Single Bing pressure-compensating carburetor
Simple muffler exhaust with muffs for cabin heat and carburetor heat
An oil change on a 2200 will require about 2 quarts of Aeroshell 15W-50 and a Napa Gold automotive oil filter. We use K&N air filters and NGK spark plugs.
Jabiru USA has sold and currently supports over 2,000 engines in the U.S. to builders of Zenith, Sonex, Kitfox, Rans, Titan, and others over the past 13 years. We have over 100 of our own S-LSA Jabiru aircraft and nearly 100 Arion Lightnings flying in the U.S. powered by the 3300.

I won't get into opinions, since mine don't count. :D
 
Last edited:
What a massive market place.

Pete I think it comes down to money most of the time. Then its all about marketing and good salesmen. Jab offers a builder a cheaper alternative and something different. In the USA we are a very diversified group of buyers. Look at all those different cars on the road and all those different types of Business jet in the air. Its such a large market place. Everybody wants a piece of the Cheese.:p
 
Katie, I think you should mention the low cost for a top overhaul or a complete rebuild compared to the Rotax ...
Hey, I'm not affiliated with Jabiru - just sayin'...
 
I was scoffed at in another thread when I tried to explain this, but the Jabiru 3300 (as I have read) performs better at altitude than the Rotax. The Rotax apparently is just about maxed out throttle travel wise at sea level where the 3300 is not. Sonex claims 170 mph true at altitude (a bit optimistic from what I understand) as it is able to maintain fairly good rpm at altitude. Of course that is up for debate :D .
 
Overhaul costs are about $1200/cylinder if we do the work here in Shelbyville. We also recommend a top overhaul (pistons, rings, valves) at 1000 hours, which costs about $600/cyl.

They do perform very well at altitude. When I go cross-country in my 3300-powered J230 demonstrator, it's 2850 rpm and 118-122 knots true at really anything under 10,000 feet. You can maintain 2850 rpm all the way up past 10,000 feet.

In case people are wondering, the prop diameter of the 3300-powered J230 is 60", and I never see anything close to 3300 rpm redline unless I push it over into a fast power dive. Cruise is a nice and easy 28-2850 rpm. On takeoff you'll see about 2850 rpm.

I don't know anything about Rotax engines, other than what they sound like.
 
Last edited:
I don't have a stake in this race as I sell EFI systems for both the 912 and Jabiru engines.

You can apply to join the Yahoo Jabiru Group : http://groups.yahoo.com/group/jabiruengines/ if you want unbiased first hand experience with these engines. You can read the archived posts until you get very tired but it is certainly not all roses.

When the engines first came out, they were pretty terrible and went through several redesigns especially with heads and a lot of extra finning added. There have been numerous issues over the years and Jabiru has slowly come out with fixes to most of them. Many people have experienced loosening head bolts even on the later engines. How much is due to poor baffling on the owners part is open to discussion. Rotec now offers liquid cooled heads for these engines so some feel the latest design changes don't fix all the issues. http://www.youtube.com/watch?v=Li9LiDYGQOQ

Many people seem to experience mild problems with high EGTs and CHTs and other problems related to the carb and poor mixture distribution.
Others have reported valvetrain issues. Yet others say the engines work great and seem to have few issues.

Granted some of these are with older engines and some may be caused by operator error or poor maintenance just as people who ignored recommendations by Rotax had problems with 912s and tended to badmouth them.

Many people feel that the latest engines are quite good if you do a proper installation and proper maintenance, others feel even the latest engines are unlikely to make TBO without some work along the way. I say education is good so read the group posts and decide for yourselves.

Just remember than Van could have chosen the Jabiru for the RV12 but did not. Rotax has many times more 912 engines flying and many times more flight hours than the Jabiru. They've had their troubles in the past too but have a good reputation now, they are just very expensive. Frankly I don't see any power to weight advantage with the Jabiru and it seems the 2200 is too small and the 3300 too big for the RV12.

Just my 2 cents for whatever it's worth. There is nothing wrong with offering an alternative to the 912 for those who want a direct drive, air cooled engine and I wish everyone the best enjoying their -12s with whatever engine they choose.
 
Last edited:
I was scoffed at in another thread when I tried to explain this, but the Jabiru 3300 (as I have read) performs better at altitude than the Rotax. The Rotax apparently is just about maxed out throttle travel wise at sea level where the 3300 is not. Sonex claims 170 mph true at altitude (a bit optimistic from what I understand) as it is able to maintain fairly good rpm at altitude. Of course that is up for debate :D .

All naturally aspirated engines lose power in direct proportion to air density as you climb in altitude. The 3300 engine is rated at 20 more hp than the 912S and it would maintain this hp advantage at any altitude. It is bigger and heavier so not strictly comparable. Kind of like saying a 540 in an RV-X performs better at altitude than a 360.
 
All naturally aspirated engines lose power in direct proportion to air density as you climb in altitude. The 3300 engine is rated at 20 more hp than the 912S and it would maintain this hp advantage at any altitude. It is bigger and heavier so not strictly comparable. Kind of like saying a 540 in an RV-X performs better at altitude than a 360.

Then end result is the only thing that is important. There is not a whole lot of difference between the 912 and the 3300 as far as installed weight is concerned. If and when Jabiru USA (or someone else) is able to put together an RV-12/3300 combo, then we will know. If it produces better climb and cruise (if that is the most important to those that chose the combination) then that is all that matters. Time will tell.
 
Lets compare apples to apples!

On the 12 we use a 70 in prop. I think I could achieve similar high power setting at altitude with a 60 in prop on the rotax.:p
 
Then end result is the only thing that is important. There is not a whole lot of difference between the 912 and the 3300 as far as installed weight is concerned. If and when Jabiru USA (or someone else) is able to put together an RV-12/3300 combo, then we will know. If it produces better climb and cruise (if that is the most important to those that chose the combination) then that is all that matters. Time will tell.

The 2200 Jab will be slightly lighter and not go as fast or climb as well as the 912S, the 3300 will weigh more, go faster and climb better. It's all about hp as far as performance is concerned.
 
What's the difference in weight between the Rotax 912ULS and the Jabiru 3300?

The 912ULS weighs just under 150 lbs. complete with airbox, exhaust, starter etc. and coolant. The 3300 weighs just under 180 lbs. in the same trim. The 2200 weighs 132-138 depending on the source. These figures from the manufacturers.

I weighed the 912 we did testing on and the figures seem accurate.
 
In the spirit of debate!

Not to sound picky just adding to the fun debate while trapped in house during winter wonder land out side. We don't use a air box on the 12. Also for a comparison for katie when you weigh the nose when you are all done mine weigh 147lbs.:rolleyes:
 
Back
Top