I don't even fly or ever touch an aircraft engine, and I've been very enlightened after listening to a half dozen of your presentations. Thanks!

I fly an AutoGyro MTO Sport which is powered by a Rotax 912ULS. It is incredibly simple to operate and very reliable. I don't have to mess about with mixture settings or worry about carb-heat. It has water-jackets around the carbs into which is pumped the warm coolant from the engine whilst the engine is running. When it's cold, it likes to be started on choke but once started, the choke is closed and the only control that the pilot needs beyond that point is the throttle. In my MTO Sport (and pretty much all MTOs from what I can ascertain), it runs very cool. In fact, I don't think I have ever seen my engine coolant or oil temperatures get up into the green band. They are always in the lower orange band once I've got the engine warmed up. A lot of people put baffles on one or both coolers to try to keep the temperatures up in Winter... at least until they come loose and end up going through the prop, that is. It's also a very efficient engine, burning around 15-16 Litres of Mogas an hour. The only thing I don't really like about the Rotax is the way they sound. They squeal quite unpleasantly compared to the lovely deep rumble of the Lycomings and Continentals.

Thank you for all infos in this session!

👍👍👍Excellence in information ! Thanks for sharing..

Really enjoyed this presentation. Very informative on Rotax engine and particularly as compared to Lycoming and Continental.

Very informative for rotax user like myself Many thanks

Please, please - how can i donate Mike an actual microphone?

Superb talk and passion sharing.

On the subject of shock-load testing after a prop-strike, I helped a Rotax engineer perform one of these on a gyro which had suffered a prop-strike. He performed a run-out check with a gauge as described in this webinar and then he placed a kind of protractor on the engine which had degree markings on it and mounted a needle to the shaft. He then took out a spark-plug and inserted a thing with a pin in it into the hole. The engine was then turned until the piston touched the pin and that was used as the base-line. The other cylinders were tested in the same way comparing the readings on the protractor to the baseline and they had to be within a margin (I think it was 2 degrees). The engine passed. It was absolutely spot-on. It was an interesting process, though. I'd heard about shock-load testing but until that point did not know what it actually involved. As for the rubber hoses. I just had a 5-yr rubber-change performed on mine and most of my hoses (except the fuel hoses) were replaced with silicone hoses because they are far less susceptible to perishing, so all being well, in another 5 years, I won't need to have them replaced.

@chippyjohn1

Жыл бұрын

That is because Rotax 912/15 are multi piece crank.

Fantastic and thank you for bringing Aircraft piston engines into the modern age. Early Continental engines were lucky to see 5 hours between TBO. This is well documented. So for Rotax to come along in the last few years by comparison to the others that have been accepted for maybe 70 years that are mostly dinosaurs and get away with Junk ignition systems and poor performance is a treasure to behold.

Excellent! Very articulate yet understandable, most helpful. I sure like my 912uls - very efficient, almost no oil consumption in 50 hours on an engine with 650 hours, no leaks...awfully expensive engine new but little expense of ownership. I only use Shell Rotax oil!

19:28 - "... creates a cooling problem..." I fly a 912ULS and the problem I have is not keeping it cool but trying to get enough heat into the engine to keep the oil runny and the oil pressure in the green. Very rarely are all of my engine instruments in the green. My engine (and the same model of engine in similar aircraft) runs very cool.

Great to see Americans and Europeans sharing technology. Lycoming makes great engines but are quite heavy. Now also just like in Europe many restrictions for light aircraft like a retractable landing gear and speed limits have been lifted.

It does take some effort, but keeping a good supply of ethanol free unleaded gasoline around is more than worth the effort.

A couple of notes here--- you mentioned no problems with the Rotax gear boxes. This is true of the boxes on these 4 cyl 4 stroke Rotax engines, and are denoted as "C boxes". The "B" boxes used on 2 stroke Ultralight engines definitely had problems some years ago. I've been out of that game for a while so don't know the current state of their B gear boxes. Note 2-- The Bing CV carbs are indeed self-leaning and do fairly well at it (you can't make it go lean-of-peak ) but they are limited to 10,000 feet. You can fly higher but the mixture is not going to keep up. This info is from a Bing service rep.

What is the efficiency of the 912 compared to an o-200 or o-235? I mean in lb/hp/hr? When looking for that, I tend to find fuel burn related to airspeed...

The Rotax 912 needs a pretty fast turning to generate spark so even if on its very difficult to start by hand, I’ve never heard of someone starting by hand. Also when turning by hand never turn backwards, it engages the starter and could damage it. Swift fuel is a high octane fuel that works better than leaded fuel

true stopped prop does have less drag

Ein Rotax besteht aus einem gewaltigen Gewirr von Schläuchen, Leitungen und Kabeln. Daher kommt der Respekt, den alle vor dem Rotax haben, aber nicht vor seiner österreichischen Qualität.

If you have a seaplane, you can always land at the dinghy dock of a marina to get auto gas, where permitted.

When I dabbled with Rotax 912ULS the external alternator was driven by belt and pulley off the front of the gearbox.I noted Paul said it was gear driven off the gearbox. Have they changed the setup to gear drive now? I

@RoadRunnerLaser

4 жыл бұрын

I don't know why yours had an external alternator. The 912ULS is built with two INTERNAL alternators. They are actually inside the crankcase and integral to the engine itself rather than a separate unit (as are the "magnetos" - which from what I understand aren't actually true magnetos). The permanent magnet(s) are on the crankshaft (or is it the flywheel?) and the coils are mounted on the inside of the casing, so the crankshaft/flywheel and crankcase are actually the alternator and "magnetos".

RE the Rotax.....with a slide projector you shouldn't let the fan for the light stay on when you finish the show, it makes the bulb cool down quickly once the light is off. For the same reason when shutting down the rotax wouldn't you want to not let it idle (idling allow the coolant to cool it down more rapidly) but rather shut down right away and let it cool off more slowly? Cyrus

why gearbox needs clutch?

Stopped prop has LESS drag! Windmilling has MORE drag!

@gmcjetpilot

4 жыл бұрын

Either is bad if flying...

35:37 I’m confused by the purpose of running at idle to facilitate cool down. I get what you’re saying about keeping the coolant flowing, but you’re also continuing the combustion process, which continues to generate heat. If you were just to shut the engine down straight away, yes the flow of the coolant would stop, but also so would the combustion. So the only thing the heads can do is get cooler. They’re not going to get any hotter after the combustion process is terminated. No?

@jomomma8754

5 жыл бұрын

The amount of heat is greatly reduced when the engine is at lower RPMS. The engine is designed to run at a high RPM, which generates a lot of heat. In order to bleed off that heat, you run at idle which greatly reduces the temperature, while you're still getting the same amount of coolant on the cylinder, which reduces the overall temperature. The concept is much the same as allowing a turbocharger turbine to cool down before engine shutdown.

@AV8R_1

5 жыл бұрын

Jo Momma that makes sense. Thanks

@richarddrapeau7599

5 жыл бұрын

I've heard the same argument for the turbo chargers. Your usually at lower operating speeds when you come in for landing. Have more airflow coming down than while on the ground. Seems weird.

@RoadRunnerLaser

4 жыл бұрын

Richard Drapeau - In some installations (like, for example, the Autogyro MTO Sport I fly), the oil and water coolers are placed near the prop, so as long as the prop is running, airflow is being pulled through the coolers. If you're coming in for landing on idle and then taxi off the runway at idle, the chances are that you've run the engine on idle for long enough to be able to shut it down as soon as you reach your parking location.

I think the problem with the GTSO geared engines is they are trying to shove 350hp through a gear box vs. Rotax at 80-100hp. Some things just dont scale well, and remain light.

cool talk. but the echo is kind of annoying

@savvyaviation

6 жыл бұрын

Hi, Daniel, we appreciate the feedback. We're looking into better audio quality.

@vernontraynor9951

5 жыл бұрын

How bout carb heat

@LTVoyager

4 жыл бұрын

I agree. It sounded like they were using two mics, one a bluetooth with some delay, and combining into one sound track. Very annoying.

Nice information, but plz don't talk with speakers on into a mic. Following is really hard when English isn't your native language

The rotax dealer guy really pisses me off he wants a monopoly on maintaining those engines. If you have the proper maintenance manual and a skilled A&P it shouldn't be that difficult to provide normal maintenance to these. If it requires super special skills to maintain a rotax then you can keep it. Rotax should offer free training online and the manuals to maintain their engines for safety.

@gmcjetpilot

4 жыл бұрын

@Jerry Moody Good points. I'm a lifetime EAA member, built two experimental aircraft both with Lycoming. I followed the alternate engine market since the late 80s. I've seen them all come and go. Yep Suzuki and Honda are the current favorite darlings. Before it was Subaru and Mazda Wankel engines. They all were the latest greatest and going to blow Lycoming away. I've seen them built at the airport, flown and what kind of performance they get. Automotive cars engines are not very suited for aircraft use in general. They are in general disappointments in aircraft. Automotive engines have lower resale. I know the pros and cons. I'm not saying they're bad or unsafe just there's a lot of compromises, and you're not really saving that much money. There's nothing wrong with the rotax, but I wouldn't call it simple. The current base engine can't be sized up anymore in horsepower. There's no replacement for displacement. In the end we're talking about reciprocating piston engines, ice internal combustion engines burning gasoline. Then we're talking about liquid cooled or air cooled. Then were talking about direct drive or a prop speed reduction unit or psru. There is weight and the engine envelope and systems, cooling drag, so many things to consider. However if you go to the Reno sport races or the Red Bull Air Races they're all Lycoming or Continental. I think all the formula Reno Racers run highly strung out Continental O-200's. I recommend people build an airplane that takes at least a 150-160 horsepower engine and put a Lycoming in it. The best engine conversion is to convert $25,000 into a Lycoming O-360. Ha ha.

@andrewarcher5611

4 жыл бұрын

GAS STATES THAT ROTAX DOESN'T HAVE THE AUTHORITY TO DECIDE WHO WORKS IN THEIR ENGINES,ANY A$P MECHANIC CAN WORK ON THEM ,ROTAX TRIES TO ACT LIKE YPUR LOCAL CAR DEALER BY MAKING YOU COME STREIGHT BACK TO THEM FOR ALL REPAIRS, BUT FAA STATES DIFFERENT AND ALLOWS ANY A&P WORK ON ROTAX ENGINES, DON'T LET ROTAX FOOL YOU AND THAT WAS ALSO COVERD IN THIS VIDIO AS WELL

@andrewarcher5611

4 жыл бұрын

Oop FAA STATES THAT ROTAX DOESN'T HAVE THE AUTHORITY TO DECIDE WHO WORKS ON ROTAX ENGINES ANY A&P MECHANIC ARE ALLOWED TO DON'T LISTEN TO ROTAX ,FAA SAYS ROTAX DOESN'T HAVE THE AUTHORITY TO DECIDE WHO WORKS ON THEIR ENGINES

@LTVoyager

4 жыл бұрын

Does Lycoming and Continental provide free training and manuals?

@gmcjetpilot

4 жыл бұрын

@@LTVoyager I am a life time EAA member and joined after I graduated after college in Mechanical Engineering 35 yrs ago. I have built two kit planes RV-4 and RV-7. YES Lycoming has manuals on line. Any "special" tool is easily bought on line for not much money. There are also videos. There are Lyc and TCM engine overall shops-O-plenty all over the USA. Every A&P can work on them. Lycoming offers a class several times a day free at Oshkosh everyday during the convention on how to tear-down and assemble. You can buy all the PMA and OEM Lycoming parts to build an engine from ECI, Superior and mattituck.... A Lyc (I)O-340 (170 HP) or (I)O-360 (180 HP) cost $10,000 less than a Rotax 915 iS which is 140 HP. at over 5000 RPM. The Lyc and TCM is built like a brick outhouse, runs longer TBO and has an impressive number of reliable flight hours over 60-70 years.... Before we get into MODERN, a Rotax is a 4-Stroke water cooled geared small displacement (like 1.35 liter - 82.5 ci). Nothing new under sun. With gear box (PRSU), water cooling, turbo, ECI there is a lot to go wrong. Lycomings and TCM have electronic ignition, electronic FI, single control FADEC (Throttle, Prop, Mixture).... Coatings of cylinders and piston oil squirters). From the get go Lycs and TCM had fordged cranks and rods, Fordged aluminum pistions, sodium filled exhaust valves....

I think the ul engines are better than the rotax engines. I don,t like the gear reduction units !! More things to break. Also lots of systems built in that can be agravating if things go glitchy!! Simple is best.

@serg2963

4 жыл бұрын

Currently, Rotax is far more reliable than any UL engine. Sorry. Interesting that all the negativity I hear about these engines, obviously comes from someone that knows very little/nothing about them.

@andrewmorris3479

4 жыл бұрын

Serg Seriously! That’s what I’ve found to be the case as well. To bring up the gearbox as a case against the engine doesn’t hold up when the PT6 is regarded as being the most reliable power plant money can buy.

@LTVoyager

4 жыл бұрын

Cars, trucks and motorcycles have had more complicated gearboxes than a Rotax and they have been reliable for 100 years now.

@martijnstam6186

7 ай бұрын

UL engines are from Belgium and have a history in modifying car engines for racing. They make great engines but for sure their quality control is not on par with Rotax. Rotax is Austrian and work like the Swiss with super perfection in mind. Also Rotax sold millions of engines.

If you would put two rotaxes on your twin right now if they made a more powerful engine then check out the rotax 916 that they sold to Lycoming and Lycoming hid it in the closet. There should be a law against this but it's perfectly legal in spite of what it's caused general aviation in safety. I'm so tired of 1935 concept engines.

echoing a lot of

Really enjoyed that, thanks a lot. I am surprised that people do still use leaded fuel, though I am surprised people still use the lycomosaurus and contisaurus engines also. Big face palm with questions about the engines being metric and if the manual is in metric. Far out, metric has been standard for over 50 years now, I can understand if you are over 70, but still bizarre. Rotax engines are certainly better than cont/lyco but are still very crude compared to modern automotive engines. I am using a Suzuki M13A, it is a far better design that a Rotax 915 from an engineering perspective. People think that something sold for aircraft is somehow the best for an aircraft. The rotax engines are 40 years old now, just have some electronics on them to look modern.

True: only use Blue Gas, Ethonal free! Never put Unleaded gas in your Rotax engine because it contains ethonal. Gasoline must be ethonal free.

@MrJpaskevich

5 жыл бұрын

Rotax can handle up to 10% Ethonal and unleaded fuel is recommended

All videos are 1.5hr long... full of great info. Why is Continental not making a new IO-200 or Lycoming IO-235. Weight? Including fluids and radiator? Rotax is not that reliable. Anything over 160HP Lycoming rules.

@andrewmorris3479

4 жыл бұрын

Rotax 912 engines are extremely reliable. Data shows they are on par compared to Lycoming and Continental.

@gmcjetpilot

4 жыл бұрын

@@andrewmorris3479 That's your opinion not data. Show me this "extremely" reliable data. I've seen, heard and read about too many Rotax failures. These high RPM geared engines have low TBO's. There are not that many flying, and most are in experimental AC. Look at the "Flying Cowboys" or Trent Palmer"s YT channels. Rotax Engine failures O plenty. Because they fly out west over unpopulated areas and in STOL planes, they just land somewhere and replace the engine, no "data". Please provide this data you talk about, not your opinion. Saying "data" with out providing data is irrelevant.

@andrewmorris3479

4 жыл бұрын

gmcjetpilot The only engine that counted during that trip was Trent’s and of course his ran flawless. Every other Rotax was hopped up and not stock that was flying out there. Leave them stock and they are near bulletproof. 4 out of 5 912 series engines have 2,000 hour TBO’s. This is on par with Lycoming and Continental. There is an active fleet of more than 40,000 Rotax aircraft engines out there right now. There is plenty of data out there for you to look at yourself.

@gmcjetpilot

4 жыл бұрын

@@andrewmorris3479 References please? Nothing you said indicates the reliability of Rotax. About Cory, Trent, flying cowboys trip to Oshkosh one guy had a complete engine failure this year. No not a 912is... 912is is based on previous 912 models. The trip year before there were several mechanicals and broken exhaust and system failures of Ritax powered planes. Trent had an engine failure, made a forced Landing about a year ago. As far as all your statistics give me references. 40,000 912is? No. If you're including the old 2-stroke rotax used in ultralights, there were a lot of them. A lot of them failed. The newest Rotax 4 stroke 4 cylinder version has only been out about a year, already had a major recall on the valves. Yes TBO has been increased on newest engines not the 1200 hrs or less of ALL the previous engines. They're very complicated with air, water and oil cooling, electronic ignition and gearbox. I just wouldn't be bragging about how "extremely reliable" they are, because they aren't. They're high-strung, high RPM little tiny displacement engines with a lot of critical systems, water, electrical, gearbox. Then there is COST! You can get a Lycoming cheaper. The Europeans got a gift from USA Gov and FAA with tge LSA class, developed in Europe which was designed around the Rotax, which as a monopoly. The rise of Rotax is because of this LSA class.

@andrewmorris3479

4 жыл бұрын

gmcjetpilot Do you know anything about the particular Rotax Trent had in his Kitfox that failed haha? Clearly you do not. You are further highlighting my point with your Oshkosh examples. None of those engines that failed were stock! Again, the 912 UL, 912 ULS, 912 iS, and 914 UL all have 2,000 hour TBO’s. The latest engine, the 915 iS has a TBO of 1,200 that will increase as they acquire more time on them in the field. I will claim they are very reliable because there is plenty of data out there that supports my 1,000 hours of flawless operation behind all of the different 912 series engines. The 912 UL, 912 ULS, and 914 really aren’t that complicated. They are still carbureted for heck sakes! The iS engines are a whole other conversation in terms of electronics but the foundation is the same. Automotive engines are much more complicated and sophisticated than these. RPM is only part of the equation. How far does the piston travel within the cylinder as opposed to a Lycoming or Continental?

Just don’t let Bombardier folks hear you say Bombardier. 😀

@lesizmor9079

3 жыл бұрын

LT might have spelled phonetically to make his/her point--- "bombardeeyay" as opposed to "bombadeer" , the latter being the guy letting loose a world of hurt. As you might have figured from this, the parent company is French Canadian.

@LTVoyager

3 жыл бұрын

Les Izmor I figured once they had a hint they had pronounced it incorrectly, it would be easy to find the correct pronunciation on the net. And hearing it is usually better than trying to figure out even a phonetic spelling. I am American, not French, but I still try to get things right when in another country or talking about them.

I understand that rotax has sold thousands of these engines and rotax builds quality products , but as a powerplant person there are a few things that concern me.........you are not allowed to split the cases and do crank and conn rod work.........the crank is pressed together and the conn rod big ends are solid , so if there is a problem with conn rods or crankshaft they have to be sent to the factory or approved depot........charge system these units use are a permanent magnet system which means if the regulator quits , the charge system will boil the battery dry in short order..........these regulators shunt over voltage and excessive amps to ground , so when the regulator fails it puts out full amps with no control........the only way to slow the charge rate is to idle the engine.........any engine that turns 5800 rpm to make 100 HP is being wrung out like a dish rag........doubling the rpm to make a required HP shortens the life of any engine..........you can make a volkswagen engine produce 350 HP , but how long will it last ????.........no engine should have the oil pump suck oil through the oil cooler .........no engine should be using crankcase pressure (blowby) as a means of pushing oil out of the crankcase to a dry sump oil tank mounted higher than the sump.........i realize that rotax has built thousands of these 912/914 engines and have good sucess , but i would change a few things if i owned one.........this is a personal opinion only.........i have a redesign for the oil tank / sump / cooler system that i feel would benefit the engine in more than a few ways........i may contact rotax and see what they say..........i would appreciate if mike busch could you contact me about these ideas to check the merit of the upgrades...........thanks

@JS-ep3sv

6 жыл бұрын

I have flown these for several years, have modified them and flown them as well. I'm a life long mechanic and can say these engines are well engineered and dependable. An example of precision is the piston to cylinder wall clearance at an amazing .001", few gaskets, ie... no head gaskets or crankcase gaskets! I fly at 5500 rarely 5600 rpm never 5800. I never had a crank or rod issue. I am flying a rebuild 914 predator drone engine now, has 912ULS pistons and cylinders. Rotax frowns on these. I never had any issues but, a crack in the case is in its future, meanwhile I'll fly it for 5-10 years. Never had an oil return problem or oil system failure and they use very little oil. I use synthetic motorcycle oil and avoid 100 LL, but if I have to use it a bit I don't worry. A simple way to rectify the rare event of a regulator failure is to run a switch to the panel to switch off one of the two alternators when stuck over charging. Use shielded wire. This will make the condition more manageable, then load up the system as necessary. Even without the switch, throttling back and loading the system will work, max output with both alternators is 18A, thats 9A each. There are better ways to control over charging when designing the electrical system. I see people overthinking perceived problems all the time. This prevents them from flying and enjoying their work. I'm not one of those people who have no thought about safety and the consequences from the lack of foresight. Sometimes you have to go with what the engineers came up with and what field experience has proven.

@serg2963

4 жыл бұрын

"but i would change a few things if i owned one". Everybody that I've talked to with Rotax problems (not many), made the exact comment you just made. Operating these engines like a Lyc/Cont is a sure way to have problems. You may be afraid of high rpms, but these little engines will do so all day long.

Your microphone sounds like You took a $4 microphone, ran it through the wash a couple times, and then chewed on it while you talked into it. Fantastic fantastic presentation but I will literally send you $100 to go get a good microphone to plug into your computers USB port

Sorry, just fell asleep...