Is the Rotary the Ultimate Light Airplane Engine?

[@LetsGoAviate]

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[@doolittlegeorge]

Mazda CX90 hybrid keeping the Wankel alive apparently so start with that I would recommend anyways.

[@WilhelmKarsten]

​@@doolittlegeorgeThe Mazda CX90 does not have a Wankel engine

[@someotherdude]

I'd like to make a bold prediction, now that Mazda has taken my advice and is producing a wankel range extender engine. I predict that hybrid electric short-flight aviation will use motor driven ducted turbines with in-line Liquid Piston motors for takeoff and climbing, and the fuel will be hydrogen. Hydrogen fuel can combusted very efficiently by the LP motors but can also be run thru fuel cells, and burns very clean. The LP motors are compact enough to actually be hub mounted, and they have the efficiency and emissions that wankels cannot achieve. They have limited life, but that doesn't disqualify them because of the low hours they'd be used- just for takeoff and climbing. They'd be better than small hydrogen-combusting turbines, as hub-mounting runs into room constraints in both intake and exhaust, along with the tiny turbine fitting on a huge shaft (for the motor-driven fan) You heard it here first, and I predicted Mazda would make a small wankel range extender. I knew they would because Sandervanderkammen said they wouldn't.

[@sandervanderkammen9230]

@@someotherdude *Stop by your local Auto Mall and ask to drive a 2024 model with a Wankel engine*

[@sandervanderkammen9230]

​​​@@someotherdude*LiquidPiston is a hoax... a big vaporware investment scam.* *The company is not legitimate in its financial or engineering integrity.* *There have been no private sales, no production, no independent reviews or third-party laboratory testing.* *Nothing but "trust us bro" and hand over your money we promise to give it back.*

[@planespotter4494]

I worked for Martin Jet Pack for a year before they went bust because they chose a 1300cc 200hp quad rotor Wankel rotary engine developed from the old Norton Rotary motorcycle. Small Light and powerful (and noisy) it seemed a good choice. But military customers wanted a unit that is fueled in Jet A-1 not petrol. And the TBO was 10 (Ten) hours. After 3 overhauls the rotor housings were to be scrapped. No customer was found accepting that kind of maintenance program. After chasing that dead end powerplant all the investor money was spent and it was all over except for a recievership sale of museum prototypes and tooling.

[@sandervanderkammen9230]

A story that has been repeated many, many times in the aviation industry.... no Wankel engine has ever been reliable enough to pass the FAA or EASA airworthiness certification test

[@joseveintegenario-nisu1928]

Norton and other developed heavy fuel RCE units, eg, John Deere, Curtiss-Wright... Ingersoll-Rand produced a 41 litre per chamber Natural Gas fueled Wankel, It gave thousands of hrs of trouble-free Operation.

[@sandervanderkammen9230]

@@joseveintegenario-nisu1928 *They were all epic failures*

[@DoktorBayerischeMotorenWerke]

@@joseveintegenario-nisu1928 Norton bought its Wankel engines from Sachs in 1977 after they abandoned development of all Wankel engines. Norton became defunct in 1991. John Deere purchased the SCORE engines from Curtiss Wright, (previously known as the RC2-320/350 and RC4-350) when C-W went bankrupt in 1985, The SCORE program was a failure and it was sold to RPI in 1991, RPI is now defunct. Ingersoll-Rand only sold a handful of Wankel engines, they were expensive, inefficient and unreliable... the program was a very expensive failure for the company and they abandoned Wankel engine production and development.

[@joseveintegenario-nisu1928]

If you use a separate lubricating system, always add some 1% oil directly into fuel, as precautory measure; Mazda had MoS2 additive in the oil of Le Mans 24 h winning Wankel. Read the Florida University SAE paper on a Heat Pipe assisted Wankel, and abandon prejudices...

[@chippyjohn1]

The liquid piston engine still has the apex seals, they just aren't on the rotor, but on the housing.

[@Handleyman]

I saw the KZbin video on the liquid piston with a clear window showing the combustion chamber. Am I correct in saying that it has three cylinders? It seemed to be a great improvement on the standard rotary engine.

[@chippyjohn1]

@@Handleyman It has 3 combustion chambers, yes. According to their website the power to weight, which is not better than your average reciprocating engine is when all 3 combustion chambers are firing per revolution. But they state the economy is only when a single combustion chamber is firing. It also refers to cooling (basically issues) when all three are firing continuously. From looking at it, it will be no better than a wankel, even worse in the sense that it has worse cooling than a wankel. Basically in sustained operation its power to weight will be worse than your average reciprocating engine. There are no demonstrations of it running at high load for a long time. Once it builds up with carbon it will score itself just like a wankel and efficiency will be even worse or no power.

[@olafschermann1592]

Yes but wo the apex seals can be cooled

[@sandervanderkammen9230]

Unfortunately LiquidPiston is not a legitimate company, it's a scam

[@someotherdude]

Sanders will shortly police this thread and tell you they aren't apex seals then. He's the grammar and wankel police! He'd be right about it, if it's not on the apex of the rotor, it's a rotor seal, not an apex seal.

[@sonnyhayes689]

Good video and well prepared. I was with Mazda many years ago and did build a 12A for an aircraft with a special gear reduction. The engine was designed to operate at 7,000 rpm. The torque is too low to drive certain props and the torque curve is just too peaky. We also installed a rotary in a small racing boat, it was very poor performing as well. The engines are very inefficient and dirty. The rotor design has large areas of fuel quench as the combustion chamber is always moving.

[@mddunlap03]

They honestly need boost if your only running a few rotors but you can make crazy power and low tq is not a issue turbines have even less tq but seting up the drivettain and gear ratios is important. Honestly more power and cheaper than turboprop when built properly 2 rotor motors can be pushed to 2000+ hp so 1200hp is doable with decent service intervals for a high performance airframe

[@sandervanderkammen9230]

​@@mddunlap03Wankel engines are completely incompatible with aircraft applications and are too dangerous for passenger aircraft.

[@sandervanderkammen9230]

​@@mddunlap03 The Wankel can't come anywhere close to the power-to-weight ratio performance of gas turbines which also have an order of magnitude greater reliability and endurance.

[@robertreasor7522]

I thought a 20B had plenty of both hp. and Tq. so it didn't have to be turbocharged.

[@sandervanderkammen9230]

@@robertreasor7522 The stock 20b was turbocharged from the factory. It was designed for a heavy, luxury model Cosmo. The 20b is not a performance engine and cannot handle high stress or high horsepower

[@jameswaters3939]

Excellent analysis. I had a friend in the 1980's who was trying to patent his rotary engine for lawnmowers. His patent application was denied as the Mazda/Wankel patent was for any and all applications and also had some in perpetuity clause that restricted any other shop's adaptation of the tech. I was amazed to hear your "hula-hoop" analogy and that's maybe where the concept originated for the development. I've heard great things about it but i have never owned a Mazda. Hybrid electrics continue to provide advantages over pure electrics, IMO.

[@sandervanderkammen9230]

That's a very dubious story considering that Mazda never patented the Wankel KKM design. _NSU Motorenwerke GmbH._ patented the Wankel engine in 1957. Mazda became a NSU-Wankel licensee in 1961 and paid 40% royalities to NSU now Audi Division of Volkswagen group. Wankel engines are obsolete technology today for the simple fact that they are inferior to reciprocating engines and have reached the end of their development potential.

[@sandervanderkammen9230]

Rechargeable batteries have extremely low energy density and their weight is the same whether they are fully charged or completely flat... not a practical alternative for any transport aircraft application.

[@jameswaters3939]

@@sandervanderkammen9230 You know more about it than I. thx.

[@someotherdude]

@@sandervanderkammen9230 it is or is on the verge of being viable for very short flights, since amps cost 1/4th as much as BTUs. Places like the Philippines, etc. So we are about one big advancement away from short electric flights quickly becoming very common. The reason is that the tickets for such flights will be absurdly cheap, since plane tickets are mostly to pay for fuel. That you wouldn't already know this is alarming.

[@sandervanderkammen9230]

​@@someotherdudeYes, but _Watts_ are same.

[@Sirmellowman]

anybody that says this has clearly never owned a rotary

[@WilhelmKarsten]

Amen! Anyone that has driven a car with one would be completely horrified by the idea of their life relying one of these keeping you in the air!!!!

[@stoneylonesome4062]

The fact that Citroën, of all companies, gave up on the Wankel, should be evidentiary that it is a dead-end. If there was ever a company known for ripping up the rule book and innovating what a car could be, it was Citroën, and they dropped it like a stone. It’s a good example of how, just because an idea is good, doesn’t mean that it will work, and just because it works, it doesn’t mean it will work well.

[@pazsion]

More reasons to use a rotary even over jet engines… much less likely to fail and easier to repair if it does fail… It’s literally the best engine for both jobs… anyone that says different hasn’t ever owned one? Or rather tried to maintain one…

[@WilhelmKarsten]

@@pazsion Jet engines have an _Order of Magnitude_ greater reliability and durability, they are the most reliable engines know to mankind. Wankel engines are so inherently unreliable that they cannot even pass the reliability test for general aviation use...

[@sandervanderkammen9230]

​@@pazsion*You can't use them in aircraft! They can't pass airworthiness certification... seals are too weak to last at P-100*

[@robertreasor7522]

I have owned a 1988 Mazda RX-7 Convertible with 102,000 miles for almost 10 years. The engine has been completely trouble free and runs exactly the same as it did when i bought the car. The Rotary community tells me this particular set up often will do over 200,000 miles. The problems come when people buy a Rotary that know nothing about the engine or how to take care of it. Also when the owner decides to add too much boost to the turbo without strengthening any internal engine parts. I can see how the Rotary could be adapted for aviation use quite easily.

[@sandervanderkammen9230]

Well, I regret to inform you that you have been lied to and given some very bad information... everything you have been told is wrong. First off, your car doesn't have a Rotary engine, it has a Wankel KKM57 engine. Mazda sold these engines under the trademark brand _Mazda Rotary®_ Which unfortunately is very deceptive and confusing. Wankel engines are inherently unreliable and much less durable than reciprocating engines, Mazda RX models typically suffer significant degradation of performance and compression loss at around 50-60 k miles.. to find a healthy engine with over 100k miles is extremely rare, 200? Never going to find one. Wankel engines cannot be used in type-certified passenger aircraft because they are too unreliable to pass the certification test. No Wankel engine has ever been reliable enough to pass a FAA or EASA airworthiness certification test, they all suffer from low MTBF (average time to failure) Apex seal failure and compression loss is the primary failure mode. Any questions?

[@robertreasor7522]

@@sandervanderkammen9230 Thank you so very much! You have saved me so much time and money I would have had to put out when my car's engine needed to be replaced.I cannot tell you how much I appreciate the honesty and integrity you have. You are indeed a grand and extra special person that gets whatever you need or want.I will never be able to repay you your kindness and your exceptional grasp of the wankel rotary engine has enlightened me so much I want to donate the rest of my time on this earth to the worship of you oh great @sandervanderkammen9230 ! At last my life truly has purpose and meaning. All hail you! oh great one!

[@sandervanderkammen9230]

@@robertreasor7522 I have a question. A completely honestly question, no sarcasm. What compelled you to buy a 25 year-old Mazda RX7?

[@stevecarlisle3323]

​@@sandervanderkammen9230More BullShit from SanderVander 🤔🇨🇦

[@WilhelmKarsten]

​​@@stevecarlisle3323Why are you spreading lies and misinformation about Wankel engines. Are you a con man? Or just a crackpot??

[@gergatron7000]

Great video. I'll add a couple of extra points about rotaries in an aero application. * They require some kind of oil injection or premix with the fuel, as do 2-strokes. This adds extra complexity and maintenance requirements. On the plus side, if high quality synthetic oil is used, it has a cleaning effect on the engine internals, preventing carbon buildup in critical areas. * Rotaries are very robust in regard to structural integrity and simplucity. If a piston engine were to sieze a bearing or piston, the engine would lock up instantly. If a valve were to stick, the failure would be catastrophic. Generally with rotaries, if there is scroring of a chamber or tip seals, the engine just begins losing power but keeps running till it slowly dies. It may be for long enough to get the plane down safely vs having an instant failure and having nowhere to land. * There was a comment made about the high rpm aspect being bad. This may apply in a recipro engine, but the rotary's only mechanical limits are the centrifugal forces on the tip seals and the eccentric bearings. Due to the fact that the rotor spins at 1/3 of the speed of the eccentric, the mechanical limit is extremely high. The practical limit comes from port flow and the diminishing ability of the plugs and chamber design to fire and harness the fuel burn and turn it into torque as the rpm rises (the burn is relatively slow).

[@NikoKyunKyun]

NEVER use a synthetic oil for rotaries, most rotaries have oil injectors, synthetic oils are hard to combust and you're just gonna spit oils out of the exhaust, always use mineral oils, unless you want to delete the oil injection and do a heavier premix, carbon build up can easily solved by revving it or use automatic transmission oil put into the rotor housing from the spark plugs, and for apex seals they're not as fragile as the internet says, heat is the enemy, so having peripheral port exhaust is important, you can also have peripheral intake for better colling to the center of the apex seals, the devil's marks is old issues, you won't see it in a smoothly ported engine

[@gergatron7000]

@@NikoKyunKyun that's the idea... The oil doesn't combust, but stays as a liquid. Mineral oil burns and leaves ash and residue in the ports and chambers. My dad's Honda NSR150 2-stroke used to get clogged up in the exhaust power valve when running mineral oil. He went to Motul synthetic race oil, and the valve cleared itself up and there was only a thin coating of synthetic throughout,showing that it has good adhesion and stability at high temps.

[@rotaryperfection]

​@@NikoKyunKyunNever you say? Synthetic is perfectly fine on engines with the 2 stoike oil adapter or pure pre-mix that doesn't pump oil from the factory oil sump. Now of course you dont want to use synthetic on factory engines that uses the OMP.

[@NikoKyunKyun]

@@rotaryperfection yeah i put "unless" in my paragraph

[@WilhelmKarsten]

@@rotaryperfection Never use 2-stroke oil in an engine only rated for 4-stroke oil.

[@bborkzilla]

I had an RX-7 Turbo II for a few years. And although it was the most fun I've ever had driving a car it required a lot of fixing (second owner). By the time I got it the apex seals were clapped out as were the side seals. The O rings that sealed the "slices" got crispy around the exhaust ports as well. It was in need of a rebuild after about 70K miles - compare that to the 300K+ I have on the boxer in my Subaru.

[@miguelgameiro8063]

Most rotaries need to be rebuilt at 70k miles and it’s not cheap the best definition of a wankel is an updated 2-stroke

[@DoktorBayerischeMotorenWerke]

@@miguelgameiro8063 Wankel... Rotary engines are something completely different.

[@miguelgameiro8063]

@@DoktorBayerischeMotorenWerke Im aware of the difference but I can only think of that French engine that spews oil so I made assumption

[@jamesrichardson645]

Something I would like to add, being involved in the design of competitive UAVs, most convential fixed wing aircraft are tail heavy, so they need counterweights in the front of the aircraft. Most jet aircrafts even have weights in the nose. So having the extra weight in the front isnt really a problem, it is actually preferred!

[@sandervanderkammen9230]

I CERTAINLY HOPE NOT. Any fixed wing aircraft that is tail heavy will stall and crash... the aircraft's weight and balance must equal across the CoG.. I think you are referring to the landing gear balance, which can change considerably when a different engine is installed from the original design (which is not uncommon) and ballast weight is added to compensate for the new powerplant.

[@jamesrichardson645]

​@@sandervanderkammen9230 You are correct, I meant to say the aircraft on its own, without any counterweights. A Large jet will be pretty spot on, but small discrepancies will need to be resolved by adding counterweights. And, slightly nose heavy is preferred than slightly tail heavy (if you must have one or the other, which realistically doesn't happen often), as it is easier to recover from a dive than a stall.

[@someotherdude]

The James Richardson from Portsmouth, New Hampshire??

[@StefOne-nw9un]

great video again! just wanted to add a mention of the fanliner and early fantrainer prototypes ;-)

[@WilhelmKarsten]

The Sachs Wankel engines developed for the Fanliner were too unreliable, they were abandoned in favor of the more powerful and reliable gas turbine engines

[@StefOne-nw9un]

if i remember right they were taken from the car manufacturer nsu and maybe modified a bit, but not completely new engines... correct me if i'm wrong

[@WilhelmKarsten]

@@StefOne-nw9un Sorry, my mistake. The KC-60 Wankel engines were developed by Sachs specifically for the Fanliner program. Sachs sold the KC-60 in 1975 to Norton and were sold as the Norton 588.

[@StefOne-nw9un]

thanx for that insight... i thought it were standard nsu car engines, and wiki also names them as such... been a while since i watched that documentary about those planes ;-)

[@StefOne-nw9un]

with "as such" i meant the name nsu... but could be they subcontracted it to sachs, a car parts supplier (e.g. my car's shock absorbers are from them)

[@johnabbott3896]

Not sayin' your wrong......but if they aren't reliable enough for the ground.... .WHY would want one at altitude?

[@devilsoffspring5519]

Mazda Wankel engines are very reliable when taken care of. I drove mine to work for years and it was already 10 years old when I bought it :) They burn too much fuel per HP produced and it's difficult to control their emissions. Wankel engines are cool but piston engines are better and that's why we use them.

[@templer46]

@@devilsoffspring5519 I don't believe you. I worked for a Mazda dealership, the engines got poor mileage and the Apex Seals would wear-out in less than 30,000 miles.

[@devilsoffspring5519]

@@templer46 We have an RX-7 Turbo from 1993 and it has the original engine at ~190,000 km. You have to take care of them.

[@aidencaterwall9146]

@@templer46they are reliable IF THEY ARE TAKEN CARE OF. If you abuse them, they break. There’s a reason the 787b crushed leman so hard. They are very reliable under power when taken care of. Planes require strict maintenance so it helps it quite a bit.

[@bartofilms]

Are you Dutch or South African? Guessing the latter?

[@mikeh2520]

I had a couple of RX-7 cars. Here are some things to think about. The exhaust gas is extremely hot. It required an air pump to inject air into the exhaust to both cool the catalytic converter and to help burn off unburned fuel in the exhaust. If the air pump fails it causes the catalyst to melt and obstruct the catalytic converter. Replacing the catalytic converter with a straight pipe lowers the back pressure but also upsets the balance of the system causing the torque to be very poor at the low RPMs. Also having the straight pipe caused big flames to show up at the exhaust pipe during gear shifts when the engine was fully warmed up. The temperature around the exhaust on just a stock rotary engine is so hot that it can burn things around it. Not what I would want to deal with in an aircraft.

[@WilhelmKarsten]

Air injection _Increases_ the EGTs by providing fresh oxygen to burn any remaining fuel in the catalyst. Damaged apex seals increases the amount of unburned fuel in the exhaust, EGTs skyrocket and the catalyst is quickly destroyed. Wankel engines are inherently unreliable and cannot pass the FAA certification test.

[@streddaz]

You can easily run a Mazda rotary engine without the cat converters, and they run a whole lot better without them. They only throw big flames when tuned to dump fuel into the engine during off throttle. This can be tuned out quite easily with the ECU. Having hotter than average exhaust is nothing that can't be engineered around.

[@WilhelmKarsten]

@@streddaz All engines run better without catalysts, what's your point? High EGTs are a symptom of low efficiency, this low efficiency in inherently fundamental to the Wankel engine design. It cannot be engineered around, no solution to the Wankel engines low efficiency has ever been found and will never be found.

[@streddaz]

@@WilhelmKarsten my point was to the comment above that stated that removing the cat causes much lower torque and for flames to spit out the exhaust, which is not true.

[@WilhelmKarsten]

​@@streddaz Removing the catalyst from an engine designed to operate with one will reduce low end torque. Modern emissions controlled engines are tuned and calibrated to operate with a specified amount of enduced backpressure so the catalyst works at optimum efficiency, simply removing the cat will reduce low end torque characteristics. Proper retuning and remapping of the fuel, ignition curves and valve timing is required for optimal performance. Wankel engines like the Mazda RX require further modification of the port timing. Anyone claiming to race Mazdas should already know this. Which casts serious doubts on some of your dubious claims of expertise on this topic.

[@MUSTDOS]

8:02, but piston engines that breakt hemselves every 10,000 km and have worse emissions due to synthetic oil leaks are allowed; gives unquestionably lower fuel efficiency too. 10:05 this has been debunked; it's quite reliable (787B) and any engine dies beyond 9000 rpm. The civil use rotaries need like a shot of 2 stroke oil for every refuel and all is well.

[@WilhelmKarsten]

Wankel engines have less than half the fuel efficiency of reciprocating piston motors and are simply too unreliable for passenger aircraft, he'll they are too unreliable even for cars! The Mazda 787B was a turd, only won a single race and that was pure luck. Mercedes beat Mazda for the 1990 le man's Championship cup and they lost to Jaguar in 91 too. Mazda doesn't race anymore... no more factory racing campaigns

[@MUSTDOS]

@@WilhelmKarsten they lost after having the rotary banned Plus, whoever made the board who made the claim rotary unreliable, are the same who made the claim that the Subaru 360 should be banned for being to small than realizing cars where getting too big. I've seen rotary engines with much better fuel consumption thanks to proper maintenance and the fact they don't Rev like mad men on 2nd and 3rd gear when highway cruising; that's the only explaination on how the RX8 had even worse fuel economy than a V8 when the US government released it's data. Most of what I've seen are 20MPG and that's for stop and go scenarios in which the rotary only fails in.

[@WilhelmKarsten]

@@MUSTDOS That's a popular but completely false urban myth. Mazda announced over a year earlier that the 787b would be retired and replaced by the Judd powered Jaguar chassis. The FIA never banned the 787b, why would they? The car lost 20 out of 21 races and never posted a single pole position or fastest race lap... it was a disappointing turd. It's an irrefutable fact that Wankel engines cannot compete with reciprocating piston engines in reliability or durability. That cannot be legally installed in certified passenger aircraft because they cannot pass the FAA reliability test. The Wankel engine typically has BSFC performance nearly half that of most reciprocating piston engines, they consume twice the kilograms of fuel per Horsepower/hour.

[@MUSTDOS]

787B was a success given it didn't catastrophically fail; it was a new design and not backed like other engines. And the RX8 would've been far more reliable if Mazda didn't make its manual sparse and had a quite faulty thermal temps especially in the engine. A similar RX8 engine is still used in Formula Mazda and didn't suffered catastrophic failures. Much better than the unholly hybrids in the long run.

[@WilhelmKarsten]

@@MUSTDOS The Mazda 787b was an epic failure that failed to bring Mazda a championship title. The Renesis suffered from horrible reliable issues directly related to it being the highest static compression ratio of any production Wankel engines, pushing the limits of the Wankel engines primitive non-vortex combustion chamber well beyond what was possible. Formula Mazda no longer exists, Mazda no longer supports any Wankel engine motorsports and has left racing completely. Audi has won Le Mans 9 times with a Diesel engine proving that even the Diesel engine is a superior racing engine compared to the Wankel.

[@brittennz]

It also has much lower vibration, but fuel consumption is horrible which comes with high pollution. It must have a reduction gear Its service life is much shorter than reciprocating. U cant push it emmidiatly to high powr. It is more expensive to make

[@sandervanderkammen9230]

Wankel engines cannot be used in type-certified passenger aircraft because they cannot pass the reliability requirements for FAA or EASA airworthiness certification

[@daledavies2334]

Old wives tales. With a PSRU and cruise power, the rotary can run all day with a prop speed of 2,000RPM and the engine turning 6,000 to 8,000 RPM. This will not degrade engine life. Most certified recips are TBO at 2,000 hours and some break cranks or rods before that. Then there is valve heads breaking off. Rotaries do not suffer those problems. The oil injection pump can be separated from engine oil and take 2 stroke oil from a separate oil reservoir. Paul Lamar prior to his passing from age related causes, was working on a Turbo Compound to reclaim waste exhaust energy and through a fluid coupling and reduction drive put that power back into the eshaft. This could bring the BSFC up quite a bit.

[@sandervanderkammen9230]

@@daledavies2334 *Please name a single Wankel engine that can pass the PFTR for a FAA or EASA airworthiness certification for passenger aircraft.?*

[@sandervanderkammen9230]

@@daledavies2334 *Paul Lamar sadly suffered from mental illness and his unhealthly obsession with Wankel engines in aircraft was a manaifestation of his illness.*

[@WilhelmKarsten]

The biggest problem is they can't pass the reliability test for aircraft certification

[@TDCflyer]

Let's talk about this in 10 or 20 years. Really good designs tend to speak for themselves. That, however, means a new design needs to tick *all* the boxes, including a competitive price. Right now I can power a relatively high performance single seat light airplane literally with a cheap lawnmower engine. Proof: see it at my youtube channel. In the more common 2-seater light aircraft market Rotax provided the 912 and it's derivates and has been dominating the market for around 30 years for the simple reason that it had the right size, weight and power *and* it was reliable. In order to break this dominance a new engine has to be better and at least at the same level of affordability. Many have tried...

[@sandervanderkammen9230]

Well, the 1960s Sachs KC-60 was developed for aircraft long before it became a troubled motorcycle engine for Norton and rebranded by Mid-west... Ever since Curtiss-Wright began development of Wankel engines for aircraft in 1958 the Wankel has left a 65 year long trail of failure and bankruptcy

[@someotherdude]

@@sandervanderkammen9230 we all know you can't stand it that Mazda is again making and selling rotary engines.... It's driving you crazy. It's eating you alive!

[@sandervanderkammen9230]

@@someotherdude Wankel engines dumbass, don't you know the difference yet?

[@sandervanderkammen9230]

​@@someotherdude*Mazda has never sold a single Rotary type engine in its entire history.* *Mazda became a NSU-Wankel KKM57 licensee in 1961.*

[@someotherdude]

@@sandervanderkammen9230 The CEO of Mazda casually refers to Wankels as 'Rotaries' in a recent interview, and if he does it, it's good enough for the rest of us. You really, really need to relax about that point. You might also go look at the YT videos which show rotary(wankels) Mazda is currently producing. By the way, a couple other companies are thinking of licensing deals because they too are shopping for a range extender engine.

[@louisvanrijn3964]

Car engine: average power used : 15-20% Light aircraft power : 65% incruise, 90% in continuous climb. Gyrocopters: 75% average.(!) Conclusion: never put a car engine in an aircraft. Wankel engine is highly dependent on intake manifold shape, e.g. reed valves. Without them torque is not present. RX7 has a very complex shaped intake manifold. Average thermal fuel efficiency of a Wankel is 13% , we measured that. Best car engines: 25-30%.

[@sandervanderkammen9230]

Great comments Love it when I see smart people leave comments, usually the KZbin comments section is populated by those on the other side of the Bell Curve. Cheers!

[@rotaryperfection]

If you're putting a rotary in a air plane and using a factory intake, you simply don't know what you're doing. It's only for rotary experts who KNOW how to build intakes that leverage low rpm torque and HP.

[@WilhelmKarsten]

@@rotaryperfection If you are putting one in an aircraft you are either crazy or suicidal.

[@sandervanderkammen9230]

​@@rotaryperfection*AVIATION EXPERTS KNOW THE DIFFERENCE BETWEEN A ROTARY ENGINE AND A WANKEL ENGINE.*

[@sandervanderkammen9230]

@@brianb-p6586 *There are no Wankel Rotary engines, only a single DKM54 prototype exists in a museum.*

[@scottboelke4391]

Also, time between overhaul about 1/3 or 1/4 of a normal engine.

[@sandervanderkammen9230]

The MTBF (average time between failures) is so low the they cannot meet minimum stanards for type-rated passenger aircraft. There are no Wankel engines available with a airworthiness certification

[@scottboelke4391]

@@sandervanderkammen9230 but is there a tbo number from the manufacturer? I have extensive experience with the rotary from the Shadow. Tbo was 250.

[@sandervanderkammen9230]

@@scottboelke4391 The 741 is the old Sachs engine designed in the early 60s...it was sold to Norton in 1974 and acquired by UAV after Norton went tits-up in 1990. No Airworthiness certification, so the TBO is just suggested as there are no legally required annual inspections or limit on hours before overhaul.

[@sandervanderkammen9230]

​@@scottboelke4391 Austro Engines sells the the larger 294cc version from the Hercules W-2000 motorcycle and the Norton Classic. It has no FAA certification but it does have an EASA exemption (part 22) for unpowered gliders, the TBO is 50 hours. Part 22 test requirements are only 120 minutes with 60 minutes at full power. FAA certification requires *150 hours*

[@jlo13800]

It’s time for ZPE powered electrogravitic engines. After watching Lockheed martins skunknworks UAP videos it leaves combustion everything in the dust. Tge aether ZPE has 10^93 grams/cv electric energy density and I can’t complain about that!

[@postulator890]

Cooling system has to be bullet proof as a lot of heat is developed on exhaust side of engine. Rotaries won't tolerate overheat as well as other types of engines. Exhaust system have to be top shelf too as there is always exhaust moving out of engine with no rest time between exhaust events.

[@formerice]

Rotaries reject a lot of heat into the oil. Need a large oil cooler.

[@sandervanderkammen9230]

Overheating is not the primary failure mode of Wankel engines, they cannot pass the PFTR test because the MTBF (mean time between failure) of the apex seal ls is too low.

[@sandervanderkammen9230]

​@@formericeNot compared to most air-cooled engines which rely on the lubrication circuit to remove a significant amount heat during high power output.

[@WilhelmKarsten]

It's the apex seals that fail, Wankel engines are completely unable to complete the same endurance test that reciprocating piston engines easily pass to earn a flight rated certification

[@WilhelmKarsten]

Wankel engines quickly overheat when the apex seals get damaged and the engine is pushed hard with low compression

[@Ang3lUki]

Reduction drives are heavy and introduce windage losses. I'm disappointed that you didn't mention this.

[@LetsGoAviate]

For anyone not yet familiar with all the pros and cons of the redrive I linked a video that covers this in-depth at 5:47

[@rotaryperfection]

Pretty much all the Rotax engines use reduction boxes so why is this a problem now because it's rotary?

[@WilhelmKarsten]

@@rotaryperfection Rotax makes engines that are certified, there are no Wankel engines certified for passenger aircraft.

[@sandervanderkammen9230]

​@@rotaryperfection*Rotary engines all have the propeller bolted directly to the engine case.* *We are discussing WANKEL KKM57 ENGINES* *Not understanding basic aviation terminology makes you look like an uneducated amateur... which is probably an accurate discription.*

[@rotaryperfection]

@@sandervanderkammen9230 And yet this video has the MAZDA rotary plastered all over it.

[@sandervanderkammen9230]

*No aircraft manufacturers use the Wankel engine for the simple reason that there are no Wankel engines available that are reliable enough to pass an PFTR reliability test for FAA or EASA airworthiness certification.* *Many have tried, all have eventually abandoned efforts to make the Wankel reliable enough for aviation.*

[@catchnkill]

Those Wankel engine manufacturers haven't tried hard enough. Mazda made a wankel engine and put it on a race car. They won one Le Man 24 hours endurance race. It was full power 24 hours reliability test.

[@sandervanderkammen9230]

@@catchnkillCurtiss-Wright, Lycoming and Continental also tried and failed. Mazda only won a single race, pure dumb luck. Mazda has never won a single world class championship title and left motorsports in failure. Mazda discontinued Wankel engines because they were too unreliable for cars!!!

[@sandervanderkammen9230]

@@catchnkill Full power? No, the Mazda R26B was severely detuned and ran at half of its full rated power during the race. Ir was the largest engine 7.8 liters

[@catchnkill]

@@sandervanderkammen9230 Motor racing is about rules. Wankel engines are treated differently. Thus it all depends on the c.c. conversion ratio with traditional 4 strokes engine. Audi won several Le Mans on a diesel engine racing car. Again it was about rules. When they tightened the rules against diesel engine cars, they bowed out. So winning a world class rate or not is not the main issue here. Is this type of engine not reliable? Not enough data to prove. At least those Wankel engines cannot be not reliable engine if they finish a 24 hours endurance race.

[@sandervanderkammen9230]

@@catchnkill Diesel engines are one of the most reliable type in the world. Wankel engines are obsolete because they are inherently unreliable.

[@plumtiger1]

i thought the rotary was bad for flight b/c the apex seals are undependable, but at the rate that engines are overhauled in aviation, it would probably be a good choice

[@sandervanderkammen9230]

There problem is the apex seals are so unreliable that these engines cannot pass a FAA or EASA airworthiness certification test. Basically they are too dangerous to install in any type-certified passenger aircraft.

[@sandervanderkammen9230]

FYI: these are not Rotary engines, they are WANKEL ENGINES. ROTARY type engines were once very successful in aircraft during WW1.

[@someotherdude]

@@sandervanderkammen9230 the ceramic material, although expensive, apparently solves the problem.

[@WilhelmKarsten]

​@@someotherdudeApparently not, considering that ceramic seals were developed by an aircraft engine manufacturer...

[@iamtheoffenderofall]

The only aircraft engine you need to rebuild after every flight.

[@WilhelmKarsten]

If you don't crash!

[@robmcquilkin3316]

Not True!

[@iamtheoffenderofall]

@@robmcquilkin3316 absolutely true.

[@WilhelmKarsten]

@@robmcquilkin3316 Wankel can't pass even the minimum PFTR reliability requirements for FAA certification... they require overhauls too often.

[@stevecarlisle3323]

@@iamtheoffenderofall NO, absolute Bullshit on your part. Check on Kyle Mohan, he pounds his Wankel drift car for a whole season, and inspects for next season, and ya he re seals, no because it needs it. Oh Man, another BOOKIE 🤣🤣🇨🇦

[@kingcosworth2643]

In Australia, you can buy an off the shelf 700hp Turbo 13B, the R&D done on performance rotaries is very impressive

[@sandervanderkammen9230]

That will self destruct after few hours in service. Not really, Australia is just decades behind the rest of the world in engine technology

[@WilhelmKarsten]

Why does Australia have so many bogus engine tuners that scam thier customers?

[@streddaz]

@@sandervanderkammen9230 You have no idea what you are talking about. They are saying that in Australia there are many performance workshops that build modified versions of Mazda's rotary engine. Australia and New Zealand lead the world in full billet engines and 3, 4 and 5 rotor variants.

[@sandervanderkammen9230]

@@streddaz Australia and New Zealand are decades behind in automotive technology, these countries no longer produce cars. These places are also rife with engine technology scams, people who live there are very gullible and niave regarding engine technology.

[@someotherdude]

@@sandervanderkammen9230 I'm pretty sure the Australians know what they're buying and whether it gets the job they want done. In fact, they run a helluva country in pretty much every way.

[@rockgoleu]

Many things work well in theory. Would love to see a 13B fly, but I probably won't see it.

[@sandervanderkammen9230]

Wankel engines unfortunately have no real advantages and some major fatal flaws which is why no one offers a passenger aircraft with a Wankel engine

[@DoktorBayerischeMotorenWerke]

A few people have attempted to use Mazda 13B engines in experimental aircraft, results were very poor usually resulting in crashes due to in-flight engine failures... many of them fatal..

[@davidmann4533]

Trust Me you don’t want a rotary in your plane

[@chrisburch3264]

Why not? Is it the reliability?

[@DoktorBayerischeMotorenWerke]

@@chrisburch3264 Yes, Wankel engines are too unreliable to pass the minimum standards for airworthiness certification... and they offer no advantages.

[@goontheracoon]

Depends.. twin engine (like sky-master), just make sure to install a parachute if all fails.. should not be a huge problem, engine weight is prob like 2×"46" ish kg, making 2x200, can easily be pushed to 250 without risk.. Just gonna make sure it has oil and it should be fiiiine, one engine goes and you can still fly under some power, just gotta enjoy checking them often to see how apex seals are doing.

[@DoktorBayerischeMotorenWerke]

@@goontheracoon Still have the problems of short TBOs, terrible fuel efficiency, high exhaust noise and the need for a propeller speed reduction unit... Wankel engines offer no advantages, only more problems.

[@goontheracoon]

@@DoktorBayerischeMotorenWerke kzbin.info/www/bejne/jXfbo2mBpLOGiLssi=xOy288v7OqwJCQOQ Not saying it's the best idea.. but heck does it pull.

[@IrishSpyHD60]

5:24 just wanted to point out the 2JZ is a 3l or 3000cc inline 6, while the 13b is roughly 1300cc twin rotor Wankel. And according to the numbers on screen the 13b makes a little under half the torque with a little under half the displacement. Seems to track to me.

[@sandervanderkammen9230]

*That is absolutely, completely False.* *"Tax Displacement" is not recognized as a legitimate or valid method of calculating swept volume displacement of the Wankel engine.* *Tax Displacement is a marketing scheme conjured up by the PR department of NSU Motorenwerke GmbH which licensed the technology around the world, in particular in countries that based vehicle registration taxes on engine displacement.* *The Mazda 13B series has a total swept volume displacement of 3.9 liters and the 2x Conversion formula correcting for the 1080°degrees firing order sequence we consider the 13b a 2.6 liter for the purpose of comparison with reciprocating Otto and Diesel engines.* *Any questions?*

[@breth8159]

After researching this in depth the decade or so back the data is redline full power will result in failure at an alarming rate making it a bad choice .

[@sandervanderkammen9230]

Excellent comments. True, the Wankel engine has an inherently low MTBF and no manufacturer has ever achieved and maintained a FAA or EASA airworthiness certification for passenger aircraft

[@rotaryperfection]

Redline failure will also apply to a piston engine. Look at all the piston failures at take off? If someone is building a rotary and gearing it to redline for full power in an airplane application, they simply don't know what they're doing. The 787b lived between 7-9k for 24hrs at lemans and still could have ran a 2nd 24hrs. Not a single piston engine can do this under those stresses in that event. Sweet spot for rotary in airplane is geared max prop speed of 2,700rpm and engine running at 5,000rpm with a large turbo making 7psi or less and running 10.5 afr. The large turbo wont heat the air as much due to it's better efficiency which will help the smaller intercooler do its job. Oil and water cooling then becomes the biggest problem which is why I would build my setup to max at 5,000 rpm to help keep all the temps in check. No need to build a rotary setup above this rpm range (unless it's NA) when you can make the power you need between 4-5k. You will essentually double the engines reliability and extending the TBO by lessening the apex seal tip speed and their centrifugal forces on the rotor housings. The only problem with rotary is too many people try to build a setup to fully take advantage of the engines high rpm capability. Not neccessary as its far to difficult to cool them. Thats when you'll have problems.

[@WilhelmKarsten]

​@@rotaryperfectionName a single Wankel engine that has a FAA certification?

[@WilhelmKarsten]

​@@rotaryperfectionWhy is there no production aircraft powered by a Wankel engine???

[@sandervanderkammen9230]

​@@rotaryperfection*You shouldn't have to worry about a "redline" failure unless your pitch control fails or you overspeed in a dive.. (perhaps if your propeller falls off)*

[@chrislutes2882]

"The rotary engine is superior to the reciprocating engine in every way....." ........ except that reliability is more important than nearly any other factor.

[@LetsGoAviate]

You put it in quotes, but thats not what I said. I said "many" ways, not "every" way. Big difference.

[@sandervanderkammen9230]

It is an irrefutable fact that Wankel engines offer no significant advantages and have several major disadvantages which is why they were the most expensive failure in the history of the engine manufacturing industry

[@WilhelmKarsten]

Indeed, if Wankel engines were superior? Every aircraft manufacturer would be using them.

[@someotherdude]

@@LetsGoAviate you don't know what you're up against with this Sander Van Der Kammen. At the very least, install security cameras, or stop advocating for Wankel engines. This guy won't rest until you agree with him! Just remind him that Mazda is in fact selling cars that have rotary engines. It's like holding up a Crucifix in the face of the devil!

[@sandervanderkammen9230]

​​​@@someotherdude​ *You wouldn't be so obviously a troll if your comments were even, at least in the slightest way relevant to aviation or aircraft engines.*

[@IsaacSchultz-lz8jc]

They do make aftermarket ceramic apex seals that fix a lot of the problems.

[@CrazyTony65]

Great for NA, not so much with turbos.

[@sandervanderkammen9230]

No, no one has even solved the problems with apex seals, they are unreliable by design.

[@WilhelmKarsten]

They make alot of things on the aftermarket that are garbage and all hype.

[@CrazyTony65]

Ianetti ceramic seals are race proven (NA) and have been for decades.

[@WilhelmKarsten]

@@CrazyTony65 Ceramic seals have been around for decades and have consistently proven too unreliable for aircraft.

[@miceinoz1181]

But rotaries are known for poor fuel consumption, even those with fuel injection. I wonder what real life TBO they would have.

[@WilhelmKarsten]

No Wankel engines have ever passed the FAA or EASA minumum PFTR reliability test required for airworthiness certification.

[@WilhelmKarsten]

@@brianb-p6586 Part H is an Exemption from meeting EASA Airworthiness Certification Standards. The AE50R can only be used in non-powered gliders. It is illegal to install one in a certified passenger aircraft as it does not meet the minimum reliablity requirements.

[@WilhelmKarsten]

@@brianb-p6586 A Glider requires no engine to operate safely. Conventional aircraft need a reliable engine... otherwise people will die.

[@WilhelmKarsten]

@@brianb-p6586 Most gliders have no engines, they are completely unpowered.

[@WilhelmKarsten]

@@brianb-p6586 Glider aircraft are specifically designed and engineered to operate safely without any engine. They have been flying without engines for over a century. Most regulatory agencies place restrictions on when and where gliders can operate that do not apply to certified passenger aircraft and powered gliders must exhibit the same flying characteristics as their non-powered version of the glider.

[@MaciusSzwed]

Wankel engines are also the ultimate engine for cars! It won Lemans and was banned ASAP! They are also ultimate for motorcycles like a small company in UK has shown.

[@TheBeingReal]

Horrible torque producers. Needs boost for any power too. The power vs SWEPT volume is horrible too.

[@waynegarfield6607]

The wankel rotary has a lower compression ratio over a 4 stroke piston type thus lower torque. It gets it power advantage from sheer speed ( rpm) the best engine power to weight is the axial flow jet turbine . A old model in a museum once visited had a 100 lbs turbine developing 1000 hp! Pretty hard to beat. Downside? Cost, fuel efficiency , emissions and maintenance. You cant have it all.

[@TheBeingReal]

@@waynegarfield6607 Good comments! The rotary also uses the ‘displacement’ of just the compression chamber, not the swept volume. So the true power vs displacement gets even worse.

[@sandervanderkammen9230]

Then why are Wankel engines obsolete? Mazda's 787b was never banned, it was patheticly slow and uncompetitive losing 20 out of 21 races. The fluke win at Le Mans was pure dumb luck, Mazda was defeated by Mercedes-Benz and Jaguar for the Le Mans championship title and Mazda left racing without ever winning a single world class championship. Wankel engines were an absolutely unmitigated failure in the motorcycle industry bankrupting many of the great bike companies. The Wankel today is the sole domain of crackpots and con men

[@sandervanderkammen9230]

​@@waynegarfield6607The Wankel engine has poor torque characteristics because of the extremely short stroke and it operates at a mechanical disadvantage, it was developed originally as a supercharger not an engine, so the geometry is actually backwards from a proper engine design. The Wankel has no advantages in power output which is one of the reasons why they are obsolete

[@simonaarekol3336]

Interesting video. The problem with the apex seal wear isn't actually a fault of the apex seals themselves, but rather the way they are lubricated. In the Mazda wankel engines, the apex seals are lubricated with the same oil that is in the oil sump. This is not a good solution since engine oil contains a lot of minerals and chemicals to make it last longer and is not made to be combusted. This can cause a lot of carbon buildup inside the engine, and lead to combustion issues that will damage the seals and/or the chamber. (Edit: The reason carbon buildup is a problem is because rotary engines get very hot, and the carbon buildup can contain some of that heat. The carbon buildup ignites the air/fuel mixture, called pre-ignition, which creates a force that the engine is not built to withstand and causes damage to the rotor, apex seals and the chamber itself. Obviously, you can't just pour two-stroke oil that is made to be burnt because it would not properly lubricate the internals of the engine. A solution that some people have come up with is to plug the hole that feeds the oil from the sump, and have a small dedicated tank for two-stroke oil that drips into the combustion chamber and effectively removed the whole issue with carbon buildup, which in turn removes the issue with apex seal tear. I really like the concept of the Wankel engine and i've always wanted it to be more mainstream (and i kind of blame FIA for banning the use of rotary engines in Group C because japan won ONE TIME with the 787B, which really halted the development of the wankel engine). I believe with more development and research, the wankel engine could become a much more reliable engine.

[@WilhelmKarsten]

Wow! You don't know much about Wankel engines and what you do is completely false myths and misinformation. The Wankel engine's reliability problems are not related to lubrication. This is popular but completely false urban myth that is easily debunked by anyone who is actually knowledgeable about these engines

[@bwest2010]

When engine power is all that separates one from safe flying and forced emergency landing on unpredictable terrain or worse water, reliability is king. No one yet has successfully developed a reliable rotary for autos, let alone an aircraft. Hard pass.

[@sandervanderkammen9230]

Great comments

[@WilhelmKarsten]

Mazda RX owners admit their cars are not reliable enough for daily driving requirements. No aircraft company would consider using them.

[@RePeteAndMe]

A light aircraft's fuel weighs more than its engine. And rotary engines need lots of cooling and radiators cause lots of drag. And the transmission adds weight and friction. Straight six beats Wankel in most categories, including take off weight. The only Wankel win is smoothness, but straight sixes are smooth enough, especially when paired with a TTTD (a flywheel replacement that uses horseshoe magnets to add torque when a cylinder is undergoing final compression, then subtract torque from said cylinder's subsequent power stroke)

[@Cuccos19]

All those years past by and not a single realibly long lasting Wankel-engine were made. The sealings at the tips could not make durable enough and the oil consumption was always high.

[@buildingracingvideos4714]

I would not feel comfortable putting my life in the hands of an apex seal

[@BoonieDutchman]

But you are comfortable putting it into: rings, wrist pin, spun bearing, broken rod, valves that might kiss the pistons due to chain breaking or chain tensioner. Makes total sense.

[@buildingracingvideos4714]

@@BoonieDutchman yes. All those things have proven themselves already, but I'm biased. I've messed with rotarys for street use.

[@BoonieDutchman]

@@buildingracingvideos4714 Proven yes, thing is, both of the engines could explode at any given moment it seriously all comes down to luck. You lose compression due to worn apex seals, sure but you can still semi run it, heck even without oil, your rod breaks and goes out of the pan, its a boat anchor. If gas was dirt cheap, co2 regulations didn't exist, companies wouldn't abandon it and find an actual solution for apex seals, rotaries would be the most reliable thing in industry. I always dreamt of easily rebuildable rotary, that didn't require pulling the engine out of the car/plane. Remove the front plate in 5 minutes, swap the worn apex seals with pliers, assemble it back. Almost like changing a filter, every 30k miles.

[@DoktorBayerischeMotorenWerke]

@@BoonieDutchman Makes total sense... because reciprocating engines can do something that no Wankel engine has ever achieved, Pass an FAA or EASA airworthiness certification test for engine reliability

[@DoktorBayerischeMotorenWerke]

@@BoonieDutchman Extensive laboratory testing has conclusively proven that you are wrong... apex seals have an unacceptably low MTBF and cannot match the reliability of reciprocating engines. The problem is loss of power, a sudden loss of power from a failed apex seal during take-off or a go-around can be fatal. several experimental aircraft have crashed for this very reason. There is no solution to the apex seal problem, its deeply flawed by its fundamental design. wishful thinking. Overhauling an engine is actually not like changing a filter... not at all, even if you could make fast and dirty repairs on a car engine, you cant do that on an aircraft that is certified, a full overhaul and inspection must be done to an "as new" standard according to the manufactures specifications and fully documented by a licensed technician.

[@cageordie]

Ignorance is bliss. Longevity and reliability don't exist in rotary engines. You don't want to bet your life on a rotary engine. They are great for drones, because they don't need a long life. The most well known issue is tip seal wear.

[@sandervanderkammen9230]

*The United States Military, the world's largest user of UAVs is completely eliminating Wankel engines from its inventory.*

[@TyReSeDuJuaN]

Apex seal

[@dougg9448]

I know a guy with a Mazda rotary on a aircraft mustang 2. He regretted it.

[@omgwtf6156]

Hi there, just one note: Primary balance can also be made perfect with only one rotor. In fact the rotor is an excentric mass rotating around with the crankshaft. This is basically a weight on an excentric lever. If now you add half of this excentric inertia on each side of the rotor you get perfect primary balance.

[@sandervanderkammen9230]

*That's not true, the triangular piston of the Wankel KKM design reciprocates while simultaneously orbiting in a planetary motion.* *Only another mass phased 180° degrees can cancel-out the reciprocating mass.* *The out of balance moment is less noticeable because the stroke of the eccentric-crankshaft is relatively short and the rotational speed is low compared to a regular reciprocating piston engines.* *Felix Wankel despised this engine, his DKM54 was a true Rotary type engine with no reciprocating mass... the triangular piston spins concentrically on a fixed axis.* *Any questions?*

[@joseveintegenario-nisu1928]

@@sandervanderkammen9230 Wrong again! Pls read the Rotary Engine balancing in the 1981 edition of Mazda's Kenichi Yamamoto 'Rotary Engine' book, available for download in the web

[@sandervanderkammen9230]

@joseveintegenario-nisu1928 *This is basic engineering, how do you not understand this simple concept?* *The imbalance of the reciprocating mass can only be canceled out by a similar opposing reciprocating mass.*

[@joseveintegenario-nisu1928]

@@sandervanderkammen9230 Read Kenichi Yamamoto. I can't teach you reading

[@joseveintegenario-nisu1928]

@@sandervanderkammen9230 Atkins Rotary is selling at $2450 all special parts needed to make a single rotor version with the housing and side plates of a 13B Renesis Mazda RX-8 engine.

[@joseveintegenario-nisu1928]

Nothing compares in power to weight ratio, and use of low RON fuels, to Wankel RCE. All its difficulties have been solved by materials, geometry,...

[@WilhelmKarsten]

Nothing comparable to the horrible lack of reliability, Wankel engines cannot be used in certified passenger aircraft because they cannot pass the minimum PFTR reliability requirements..

[@joseveintegenario-nisu1928]

@@WilhelmKarsten False! No one ever attempted to certify an RCE for General Aviation because there is no series produced Aircraft in the Wankel power range. What about the Austro rotaries? Before reckless assertions, please check and consult references. Is anybody in the Aviation Industry paying your slander, or you are just a troll, hunting for independent minds? People like you support Zelenski, Netanyahu, war criminals.

[@WilhelmKarsten]

​​@@joseveintegenario-nisu1928 LOCKHEED CURTISS WRIGHT NSU LYCOMING CESSNA BEECHCRAFT CONTENINTAL VAZ CITROËN RBF GRUMMAN SACHS MID-WEST MISTRAL HAVE ALL ATTEMPTED TO CERTIFY WANKEL ENGINES FOR PASSENGER AIRCRAFT!!!

[@WilhelmKarsten]

​@@joseveintegenario-nisu1928Austro does not offer any Wankel engines that are certified for use in powered passenger aircraft.

[@sandervanderkammen9230]

*Austro Engines doesn't meet FAA and EASA airworthiness certification for passenger aircraft.*

[@dmitryrmm8743]

The problem with Wankel is very few people outside Germany can pronounce it correctly.

[@robertweekley5926]

Western Canadian here: "Fee Licks Wank EL!" (Felix Wankle)

[@Subar_Sama]

Two things I'd like to comment: 1. It's true that the rotary engine has worse fuel consumption, but in the aviation world it's not too much of a difference since engines are working at a constant speed during flight. They're actually quite efficient if working at the right speed (there are papers published that confirm this). The Wankel engine is a high duty cycle engine (I don't know if Felix Wankel realized this when designing the engine), whereas a piston engine is a low duty cycle engine. 2. The apex seal problem can be solved by using ceramic apex seals. They're designed to withstand the high temperatures of the Wankel engine combustion chamber, which are noticeable higher than a piston engine combustion chamber, and they're basically indestructible. However, the problem with ceramic apex seals is that they're ridiculously expensive, which is why cast iron is used as the material for apex seals in stock engines. Other than that, great video! I enjoyed every second of it.

[@sandervanderkammen9230]

THAT IS COMPLETELY FALSE, Wankel engines average roughly Twice BSFC fuel consumption compared the reciprocating engines. There is no evidence to support otherwise. Wankel engines are inherently unreliable and extremely prone to failure at continuous high power output typical of aircraft applications. No engine manufacturer has ever managed to achieve a FAA or EASA airworthiness certification for a Wankel engine. The MTBF of the apex seals is far too low to be safe for passenger aircraft. No solution to the inherently unreliable apex seals has ever been found.

[@Subar_Sama]

@@sandervanderkammen9230 Why then did Mazda win the 1991 24 Hours of Le Mans with a Wankel engine only getting minimal wear and tear? Care to explain that to me?

[@sandervanderkammen9230]

@@Subar_Sama *PURE DUMB LUCK!* Mazda's win at Le Mans was nothing more than a fluke. The Mazda 787b was hopelessly slow and uncompetitive, it lost 20 out of 21 Le Mans series races and never posted a single pole position or fastest race laps. The 1991 24 hours of Le Mans race started out with a massive wreckage that knocked the series points leaders, Mazda qualified in the back of the field ans so far back they avoided the massive pile-up. Mazda walked across the finish line with a record low numbers of laps and the slowest average speed.

[@Subar_Sama]

@@sandervanderkammen9230 You're clearly trolling at this moment. Goodbye.

[@sandervanderkammen9230]

@@Subar_Sama Serious as a heart attack kid. Check the records yourself. I watched the race in 1991, were you even born yet?

[@devroombagchus7460]

Who needs light Airplanes?

[@briankenney4287]

There is another very significant negative that you did not mention. The engine exhaust is controlled by a port, similar to a two-stroke engine. This type of valving is extremely loud. Aircraft typically do not have effective mufflers because of weight and packaging limitations so the typical noise levels of a rotary will be, in my opinion, too loud. Such airplanes are unusable from a passenger and neighborhood perspective. The only solution is to use a turbocharger, which is another level of complication, with its own limitations and dangers.

[@DoktorBayerischeMotorenWerke]

The first and most serious problem remains that no Wankel engine has ever been reliable enough to pass even the very minimum standards for airworthiness certification.

[@FairladyS130]

A rotary aircraft engine is different to that which is correctly named a Wankel engine.

[@LetsGoAviate]

As explained towards the start of the video at 0:19

[@FairladyS130]

@@LetsGoAviate yes, but it is still called a rotary.

[@boydw1]

@@FairladyS130 Yes, but actual rotating cylinder "rotary" aviation engines are so rare they're not even worth mentioning, and were quite rightly abandoned 100 years ago.

[@FairladyS130]

@@boydw1 Seen plenty of videos of those 'abandoned' real rotaries recently.

[@boydw1]

@@FairladyS130 Maybe you're confusing them with radials. There's still a few aviation rotaries out there, pretty much exclusively on restored ww1 era vintage aircraft.

[@jimsvideos7201]

Pining for rotaries is chasing perfection to the detriment of good enough. The writing is on the wall for gasoline aviation engines too.

[@WilhelmKarsten]

Rotary engines became obsolete in the 1930s. Gasoline powered aircraft are not going anywhere for a long time.. there are currently no viable alternatives.

[@Marco-ip5cw]

they really arent unreliable theres so many race cars and other rotary powered vehicles that are pushing so so much more power than they were made to have when they came out rob dahms rx7 is making over 1200hp with full time awd making a metric buttload of boost and its been doing it reliably aswell as other projects he has specially considering all the experimental stuff on that car

[@kingcosworth2643]

In Oz a 700hp 13BT is just a phone call way, this power level is easily achieved thee days.

[@sandervanderkammen9230]

So why are Wankel engines so unsuccessful in motosports? Mazda left racing completely without ever winning a single world class championship title. Rob Dahm? Are you talking about the coke dealer that sells T-shirts with his name all over them? Who has a long history of spectacular engine failures? Who pays other people to build his engines because he is a "software designer" and not a mechanic? That Rob Dahm???

[@sandervanderkammen9230]

​@@kingcosworth2643And compression loss can easily be achieved in one day....

[@WilhelmKarsten]

Wankel engines are hopelessly unreliable, so unreliable in fact that they are unable to complete the endurance test required for production aircraft.

[@stevecarlisle3323]

​@@sandervanderkammen9230See, this is the type of guy, SanderVander Really is.😞🇨🇦

[@OCofthe3]

Is this entire video a troll? If so, its a good way to get a lot of comments and views so nice job if that's your intention. But if you ever really studied the rotary engine, you will know right away why it was a developmental dead-end and has no place in an aircraft or pretty much anything else except for a few niche applications. A gear reduction unit is a pretty damming case against using the engine right off the bat. You will need to include the gear reduction unit in your parts count and durability calculations. Also, even though the engine has less parts, it doesn't mean those parts are simple and contribute to reliability. Honestly, you should count all of the moving seals and springs in your parts count since those are critical to the engines function. Somehow everyone forgets those important parts when counting the parts. Many people much smarter than myself have been down the rotary road before, all discovered that the design is inherently flawed and abandoned it.

[@LetsGoAviate]

Great comment and good points, apart from the troll thing. Really? No the video is not a "troll". I raised a hypothesis that the Rotary is the ultimate light airplane engine and presented some facts and my reasoning for my proposition. If you think it's a developmental dead-end, you better let Mazda know quickly! Maybe if you said it's a dead-end for primary propulsion, it would have hit harder, since it's viability for range extenders in EV's are excellent. Closer to home (aviation) Diamond also don't seem to buy into it being a dead end. If you agree that fewer parts doesn't always mean better reliability, then by extension you know that more parts doesn't always mean worse reliability. Thus I don't agree that a gear reduction unit is a "damning case" against the rotary, it certainly isn't a "damning" case against the Rotax 9 series engines, as an example. If the PSRU is of a good design AND is maintained as per manufacturers instructions, they have an excellent track record with failures being extremely rare. I maintain the reason the rotary isn't developed much more is because of it's emissions problem which can't be fully solved (as opposed to reliability problems which can be solved). The emissions however isn't as big an issue in general aviation as in motoring, but don't take my word for it. AVweb's Paul Bertorelli recently released an excellent video called "Decarbonize Aviation? Good Luck to Us" which explains it well.

[@OCofthe3]

@@LetsGoAviate I apologize since you seem serious about the question. But really, after you understand the short comings of the design, I think you might look at things differently. I would be happy to go over every aspect of the engine with you to help you understand why the wankel design is a poor choice and has issues that can never be fully resolved. These include but are not at all limited to: complicated sealing, uneven heating, poor thermodynamics, noise, carbon buildup issues, and decreased range for a given output. Mazda does not pursue the engine because its superior, they pursue it because its a novelty.

[@sandervanderkammen9230]

EXCELLENT COMMENTS

[@doolittlegeorge]

Standardized propeller design is why the need for gear reduction. Change the geometry of the propeller may allow for high rpm without gear reduction. Might be able to use for auto gyro work as well.

[@LetsGoAviate]

​@@doolittlegeorgeYes simply reducing propeller blade length allows higher propeller rpm, but longer propellers are more efficient, which is why airplane propeller blades for the most part have always been as long as is possible.

[@ATomRileyA]

Rob Dahm has entered the chat :) I seem to remember that some military target drones had rotary engines.

[@sandervanderkammen9230]

Rob Dahm? The guy who made a video about the benefits of mixing cocaine and Adderall? Who sells guady T-shirts with his name all over them? Who pays other people to build his engines because he is not a mechanic or an engineer? Who's engines always blow-up??? That Rob Dahm??? Aren't drones made to be disposable? I think the Wankel is too, sounds like a perfect match!!!

[@ATomRileyA]

@@sandervanderkammen9230 lol did your missus run off with a RX-7 owner or something :) You seem very silly and stupid, but it did make make smile so there is that.

[@sandervanderkammen9230]

​@@ATomRileyAWhat kind of pathetic loser drives a 30 year old Mazda?

[@someotherdude]

@@sandervanderkammen9230 then you have literally just admitted wankels are excellent for something the world will always need, which are drones.

[@sandervanderkammen9230]

​@@someotherdude*WHO WANTS TO FLY IN A PLANE WITH A DISPOSABLE ENGINE????* *DAMN YOURE IGNORANT SON!*

[@danbenson7587]

1. Air cooled aircraft engines aren’t particularly fuel efficient perhaps a wankel is par.. 2. The wankels other attributes are failure non-catastrophic slow loss of power, cheap to overhaul..like real easy and cheap. 3. Torque curve matches propeller curve so low torque is non issue at low RPM. 4. Isn’t the Apex seal issue not wear, but carbon build up. Resolved by either fuel or oil additives. Compared to piston engine, The Wankel’s exhaust blow down is hotter and pressured. It’s a natural for Turbo-compounding. Shaft the turbine to the PSRU. Efficiency ^ 20%.

[@WilhelmKarsten]

Where do you get this kind of egregious misinformation from? Nothing in your comments is accurate or true.

[@danbenson7587]

@@WilhelmKarsten I’m just a stupid Mechanical Engineer and a pilot since 1969. So you’ll have to be specific as to the errors in my thinking.

[@WilhelmKarsten]

@@danbenson7587 It's not unusual for a Lycoming air-cooled engine to have a BSFC of 0.4 or less... thats less than half the fuel consumption of a typical Wankel engine. Wankel engines cannot safely run 'Lean-of Peak' either, you must cruise with a rich mixture. That's wishful thinking considering that no Wankel engine has ever been reliable enough to pass a FAA or EASA PFTR requirements for airworthiness certification. The cost of parts and repairs for automobile engines will always be much cheaper than a type rated aircraft engine because they are not certified! Completely moot point. When just comparing automobile engines the Wankel has a higher initial cost and higher operating costs than a reciprocating engine. So no cost advantage with the Wankel. The Wankel has overall poor torque characteristics and BMEP is terrible compared to reciprocating engines. The primary failure mode of all Wankel engines is apex seals and compression loss. The issue is high brisance and ablative damage during continuous high IMEP conditions like take-off and climb out. The apex seals have an extremely low MTBF, too low for safe use in passenger aircraft. Carbon build up is a symptom of low compression, no different from reciprocating piston engines. Carbon is a good indicator that the seals are damaged and compression is below acceptable readings. Unfortunately no, Wankel engines are very poorly suited to combined cycle exhaust gas turbines, the Wankel engine's extremely low combustion chamber efficiency and low conversion rate make the EGTs too high for reliable operation. Much richer AFRsare needed to quench the EGTs thus canceling out any advantages of additional heat recovery cycles. Any questions son?

[@danbenson7587]

@@WilhelmKarsten Adults disagree w/o being snippy (eg ‘son’). Returning to the debate EFFICIENCY. Gas turbines like PT6, T250, TPE331 are less efficient than a piston (say .63 vs .45 sfc) Their success in the +300 hp market means fuel efficiency is not a primary market requirement. If sub 300 hp GTs were available, I’m sure they would replace Lycoming and Continental . To the aviation market, reliability trumps efficiency. Rotary’s combustion chamber and large wetted area stink vis a vis a piston engine. But rotary auto engines are tuned for broad rpm range, whilst aero engines run between 70% and 100% power. The point: a rotary tuned to aero requirements would enjoy an appreciable sfc improvement. Lyc getting .40 sfc is a pipe dream. The compression ratio is 6.5 to 7, open (non squish) chamber, air cooled. But I’ll concede if you can provide a source. RELIABILITY . I’m my view, the rotary is the poor man’s turbine. A two chamber rotary has 3 primary moving parts versus 22 primary moving parts on a 4 cylinder Lyc. The rotary fails by loss of performance, not catastrophically. Lyc. fail how many ways?...dropped valves, cracked cranks, cylinders completely blown off, spun bearings etc. I had an C-172 w/ O-300 Cont. catch fire; it was a close run thing. DURABILITY. Mazda whipped the apex seal issue decades ago. They are currently producing the MX-30 engine. Would Mazda invest billions if apex seal life was an issue? (BTW ...KZbin has MX-30’s being built). In addition, The rotary has excellent balance so benefits spill over to reduced airframe cracks. Lycoming and Continental engines’s broad cylinder spacing, ‘S’ shaped crankshaft throws, sloppy tolerances, and air cooling are antipodal to long life. I am amazed they do as well as they do as they beat the shit out of themselves every revolution. REBUILD. For a rotary, it’s disassemble, replace seals, reassemble with new oil and water pump, then test. Lycoming and Continental disassemble, magnaflux, measure, refurb cylinders, new pistons/rings and on and on. All with paperwork. Then after spending 40-50$k you still have an engine with an unknown remaining fatigue life. FAA. I don’t know the rotary’s certification history. I do know Certification is more than witness testing the product, it’s the whole paper trail: calculations, quality system certification, building process, material traceability, certificates of conformance. (Thus why auto engine conversions are near impossible to certify). These impediment dissuades all aero engine manufacturers from product improvement.. but that’s another story. There is no intrinsic reason a rotary running on mo-gas is un-certifiable. COST. Rotary’s have fewer parts are going to be cheaper in the diminutive aero market. From above, it’s not just a part..it’s the paperwork. TORQUE. The aero engine torque output must simply exceed the prop’s n^2 requirement. Non issue. COMBINED CYCLES. Wilkepedia ‘Mazda Rotary’. Find a list of turbo’d rotary engines. A few remarks about turbo...The pressure rise across the compressor and the pressure drop across the turbine are practically the same. A turbo engine effectively runs at an overall higher pressure. When the exhaust opens, The engine blows down from a pressure about equal to the cylinder compression pressure at TDC. The turbo compound engine captures this blowdown energy. (These remarks are first order, it’s more complicated) In a piston engine full turbo pressure is across the rings and piston. In a rotary, the full turbo pressure is across the side seals. The apex seals are pressured from BOTH sides. Raising the rotary’s overall pressure via turbo is not fully visited on the apex seal. The bug with turbo compound piston engines is exhaust valves crapping out. The rotary hasn’t exhaust valves to crap out. Mazda’s turbo success suggest EGT a non issue. Turbo rotaries are over boosted, whereas Lycoming and Continental are turbo normalized. A turbo rotary potentially has superior specific weight. TECHNOLOGY. Mazda has the monopoly on rotary tech. Piston tech is ubiquitous. At the end of the day the market and certification hurdles dictates Lycoming and Continental. An aero Rotary is a dream and always shall be. Nonetheless I think a good fit for planes, a poor man’s turbine. But so what? It’s not going to cost me sleep. The aero market crawls toward the Diesel cycle, not for efficiency, but JP4. This mutes our rotary versus Lycoming discussions. Cheers D

[@WilhelmKarsten]

@@danbenson7587 Wow! That is a comment filled with wishful thinking, pure speculation and outright fantasy. The PT6 achieved 0.49 BSFC when it was introduced in 1961. The EPI TP-400 achieves 0.350!!! Thats 40% TFE!!! There are no sub 300hp GTs because of COST, they are too expensive for GA. However GTs have rendered reciprocating piston engines obsolete in commercial and military aviation because of the incredible horsepower-to-weight performance and long term financial benefits of their long service life which is an order of magnitude better. In General Aviation cost trumps everything, reliability is regulated by government agencies. Not a valid argument, as peak BSFC efficiency occurs at WOT, exactly where the Wankel engine shows its biggest weakness. That comment is a major blow to your credibility, here you are again talking pure speculation without any shred of evidence or a functional understanding of the topic. The IO-720 was the first the Lycoming engine to break the 0.40 BSFC, that was back in 1961! In my view, you sound like someone who is a poor man, too poor to own a plane anyway. Unfortunately automobile engines have proven unsuitable for aircraft applications except for the most reliable manufacturers like Porsche and Mercedes-Benz, and even then with limited success due to higher costs. You mean the O-300? That's a type rated aircraft engine. There are no type rated Wankel aircraft engines... they all failed to meet the minimum PFTR requirements for airworthiness certification. Mazda went bankrupt in 2009 after one of the biggest premature engine failure recalls in history involving apex seals in the Renesis. Mazda has never made a profit from Wankel engines and has gone bankrupt twice because of them. Both Lycoming and Continental developed Wankel engines but they consistently failed the same durability and reliability tests that thier reciprocating piston engines easily passed. You obviously know nothing about FAA or EASA airworthiness certification. No Wankel engine has ever been reliable enough to pass certification.... Apex seals have proven too unreliable. Wankel engines are more expensive and they have many tiny fragile seals that are the source of their unreliability. Wankel engines offer no advantages in torque or horsepower characteristics, that is a matter of propeller selection and efficiency. Reciprocating engines are ideal for props because of their low rpm torque and horsepower output. Mazda's disappointing failures with turbocharging speaks for itself... turbos and apex seals don't mix! Just ask Tom Parkes or CJ.Jackson, they both crashed because a broken apex seal took-out their turbochargers during a critical climb-out phase. The reliability of turbochargers on reciprocating piston engines is excellent and not in question. JP-4 is obsolete son, has not been used in many years.

[@NSResponder]

Liquid Piston's design is a new take on the rotary concept, and it's clearly superior to the Wankel for power/weight ratio while maintaining the small frontal area advantage. It gets three power strokes per revolution while the Wankel only gets one.

[@someotherdude]

It's way harder to produce and has a very limited life, and a scary hollow crankshaft.

[@Handleyman]

The liquid piston rotary engine is a game changer.

[@sandervanderkammen9230]

Same old ponzi scam that people keep falling for.

[@WilhelmKarsten]

BEWARE OF LIQUIDPISTON it is not a legitimate concern and is a investment vaporware fraud

[@jdoe9518]

BSFC. The Rotary has poor BSFC. Which is why it has high fuel consumption and high emissions. BSFC stands for Brake Specific Fuel Consumption. It tells you how much fuel your engine will use per hour for each horsepower it makes. I'm pretty sure fuel = weight and weight = bad in aircraft So why would an engine that's far more inefficient than a well designed piston engine be a good idea? The Rotary engine and how it operates is completely misunderstood by just about everyone. People don't even understand how to compare it to other engines. 2 and 4 stroke engines are named for the number of movements to complete a full cycle. How many movements are required for a rotary to complete a full cycle? If you manage to work it out it will become clear that the capacity and output are not what you believed. Also apex seals are rarely a failure point, except in high boost applications. It's the rotor side seals that cause the most problems.

[@sandervanderkammen9230]

Apex seal failure is the primary failure mode of all Wankel engines. No aircraft engine manufacturers have ever resolved the problem of apex seal failure during airworthiness certification testing.

[@jdoe9518]

@@sandervanderkammen9230 What causes apex seal failure? What is an apex seal failure?

[@sandervanderkammen9230]

@@jdoe9518 Apex seal failure is caused by erratic combustion and detonation in the Wankels very primitive non-vortex type combustion chamber, this creates high brisance and ablative damage to the surface of the apex seal directly exposed to the burning gasses. They are unlike piston rings which are protected from damage by the piston crown and ring lands. Apex seal failure is typically the inability of the seal to continue forming a gas tight seal and the resulting loss of compression and engine power. Catastrophic Apex seal failure can cause broken seal and tension spring parts to detach a contact the housing wall or end plates.

[@sandervanderkammen9230]

@@jdoe9518 Aircraft engine manufacturers must complete a PFTR (Preliminary Flight Test Rating) before they can apply for a FAA or EASA airworthiness certificate. Depending on type of application the engine must be run in a test cell at P-100 (full rated power) for typically 100 hours or more without any failures and no significant loss of power. No Wankel engine has ever been reliable enough to pass and maintain a FAA or EASA airworthiness certification. The primary failure mode during these tests is Apex seal failures. The MTBF is simply too low for Wankel engines to be safely used in type-certified passenger aircraft. They can only be legally used in gliders, UAVs and experimental aircraft. Any questions?

[@jdoe9518]

@@sandervanderkammen9230 So exactly how erratic is the combustion? It sounds like these engines are lucky to run at all? Are all apex seal materials effected in the same way? Ceramic v steel v carbon seals So piston rings run in ring lands what do apex seals run in? Oh and do apex seals prevent combustion pressure entering the sump?

[@robc1014]

Wankel engine. ‘Rotary’ engines in aircraft have been something different from wankel for a very long time. Cylinders are set in a radial configuration. The engine's crankshaft remained stationary in operation, while the entire crankcase and its attached cylinders rotated around it as a unit. When mentioning or educating in aviation its good to make and keep this distinction to avoid confusion.

[@LetsGoAviate]

0:19

[@sandervanderkammen9230]

​@@LetsGoAviateYour video is unfortunately confusing and inaccurate. You say "Wankel rotary" and show an image of the DKM54 But you clearly described the Non-rotary version called the KKM57??? Are you not aware there are two types of Wankel engines?

[@PhilipFly11]

The Wankel engine has 2 problems that make it difficult to choose over a reciprocating engine: 1. The specific fuel consumption is higher than gasoline piston engines when designers and manufacturers are switching to diesel piston engines which are more efficient eh Continental and Deltahawk 2. The noise of a Wankel is like a Formula 1 engine with an open exhaust pipe and it takes a large and heavy exhaust system to reduce this to non- earsplitting levels Torque and high rpm are a complete non-issue. If the reduction unit reduces the propeller speed x 3 then torque is multiplied x 3 . . . . gas turbines run at much higher rpm, small gas turbines can exceed 100,000 rpm, however, after the turbine has had its speed reduced for the propeller nobody is going to complain, for example, that the turbine engines on a Lockheed C-130 Hercules do not produce enough torque to swing their propellors!

[@DoktorBayerischeMotorenWerke]

The Wankel engine has one huge problem in aviation applications... they are too unreliable to pass even the minimum airworthiness certification standards, not one single Wankel engine has ever successfully completed a FAA or EASA type-rating certification process application. No Wankel engine can be legally used in any type-rated passenger aircraft.

[@AxianMapping]

Has anyone even watched the video? He literally says there is little to no hope for the platform in the aviation sphere.

[@WilhelmKarsten]

*Anyone familiar with the Wankel engine and the aviation industry knows the Wankel was an epic failure...* *Curtiss-Wright, NASA, the FAA and the USAAF combined forces to develop Wankel engines for aviation, billions of dollars and 26 prototype aero engines later... not a single engine was reliable enough to pass airworthiness certification tests.* *It was the most expensive failure in aviation until the Concorde program.*

[@peterclark6290]

Emissions, the Wankel can't burn off some rather unwanted gasses. So unless you can sort that out this idea is only suitable for developing nations and internal traffic.

[@sandervanderkammen9230]

Too unreliable for passenger aircraft... plus terrible fuel efficiency reduces range and payload

[@josega6338]

TBO in a Lycoming engine is suggested as 2'000 hrs; for a P&W turboshaft, they say 3'000 to 6'000 hrs MidWest aeroengines, aircraft versions of Norton Wankel, proposed they will sell a new Birotor for the cost of a Reciprocating Engine Overhaul. Citroën said production cost of Single Rotor, 995 cc, 60 HP Wankel in M-35 would be less than making their traditional 602 cc, Air and Oil Cooled twin-flat. Skypower is selling Wankel integrated generators, good for hybrid vehicles and Aircraft

[@sandervanderkammen9230]

Lycoming and Pratt&Whitney engines are certified for manned flight, MidWest went bankrupt and was bought by Diamond(Hoffmann Flugzeugbau) and became Austro Engines. Austro does not make manned rated type certified engines... they are restricted to use in gliders. Citroën's attempt to make aircraft Wankel engines ended in failure, their helicopter engine was underpowered and too unreliable, the program was terminated.

[@DoktorBayerischeMotorenWerke]

MidWest failed repeatedly to obtain EASA airworthiness certification... they became insolvent and were sold by a bankruptcy court. Citroen went tits-up after attempting to sell Wankel engines for cars... another epic Wankel engine failure in history!

[@josega6338]

@@DoktorBayerischeMotorenWerke Do you need an engine Certification to install in a Homebuilt? They mount 2-Strokes, absolutely unreliable for manned flight. Citroën Comotor Birotor failed because of poor fuel economy. There are many avionized Mazda flying. Certification does not interest me, and yes, there is a war against Wankel, after Mazda 787 won Le Mans endurance and economy race, rules were changed to ban it.

[@josega6338]

My only interest in Wankel is Street Cars

[@sandervanderkammen9230]

@@josega6338 Your interest appears to be spreading egregiously false and benighted misinformation about a topic that you are very confused and unqualified to discuss intelligently. Stop posting ignorant misinformation about Wankel engines.

[@reinerressel975]

Car engines are developed for 15/20% continuous power ! Remember Porsche , they vanished silently , if you don’t close the throttle to suck oil directions to the burning chamber , it run dry !!! Therefore aircraft engines has half or full wedge piston rings ! Car engines won’t last in a Aircraft !!

[@sandervanderkammen9230]

Porsche's 911 engine is so durable and reliable that it was granted a FAA airworthiness certificate (PFM 3200) Mercedes-Benz is the only other automobile engine that is full certified for passenger aircraft (OM640 - Centurion 2.0)

[@WilhelmKarsten]

Porsches have a dry-sump lubrication system like aircraft They are the King of endurance racing having won the 24 hours of Le Mans 19 times!!!.

[@someotherdude]

@@sandervanderkammen9230 Porsche's foray into diesels didn't go well at all. And since I know you have so much pride wrapped up in the Germans, let me remind you that at present, German cars are an utter embarrassment. Still wonderful to drive of course, but unreliable, filled with electrical gremlins (especially VW and BMW) and highest cost of ownership over a 10 year period. That is NOT what German prices should buy you. And then there was Dieselgate. So don't be so smug on all things German. At the moment, the state of their cars is shameful.

[@sandervanderkammen9230]

@@someotherdude *Porsche has won Le Mans 19 times and their production Auto engines can pass FAA airworthiness certification... something that no Wankel engines ever has.*

[@sandervanderkammen9230]

@@someotherdude *BMW is famous for making some of the best aircraft engines in history.*

[@balljointfd3s]

God dammit man.... you did it... Of course you did it... The Apex Seals... Ugh.... You know there are drag cars making 1,400HP on Two Rotor engines, over 2,000HP on Three Rotor engines. The problem is not the Apex Seals on these motors, it's the motors literally twisting themselves internally, the Apex Seals... Totally fine...It's people like you that know nothing about Rotaries that give them this rep to this day... It's this damn simple, if the car makes less then 400HP put 1oz of two stroke oil in the gas tank per gallon of Gasoline. if over 400hp or if under heavier stress then 1.5oz per gallon (you're not going to hurt anything here). It's... that.... simple...

[@WilhelmKarsten]

Wow! Are you even old enough to drive yet kid? Everyone knows that Wankel engines like to shit their apex seals out the exhaust in the most unpredictable fashion... these things are too unreliable even for cars, Forget airplanes unless you're feeling suicidal! Hahaha!!!!

[@thatcornfedrx8guy372]

they have found solutions to the motors twisting internally, usually people add extra dowel pins and or studs to keep the engine from over torquing itself, don’t forgot people have also made two piece and 3 piece e shafts to keep that from happening.

[@WilhelmKarsten]

@@thatcornfedrx8guy372 No solution has ever been found to make Wankel engines reliable, they are obsolete technology today... the sole domain of hacks, crackpots and con men.

[@DoktorBayerischeMotorenWerke]

@@thatcornfedrx8guy372 No one has ever found a solution to the poor reliability problem that prevents Wankel engines from passing the minimum standards for airworthiness certification.

[@jacobchandler2083]

@@DoktorBayerischeMotorenWerkepretty sure the people who would put a wankel in a plane could care less about certification. Same general boat as an ls swap plane. Definitely can have problems that typical aircraft engines might not. But most typical certified aircraft piston engines are designs from the 50s. Thats not necessarily a bad thing but being stagnantly reliant on leaded fuel when automotive engines figured that problem out years ago sorta is lazy

[@gmcjetpilot]

PSRU is BAD, they are a failure point. PSRU's for automotive to aircraft conversions are always problematic. WATER cooling requires a radiator, difficult to incorporate and be low drag. 7:29 is picture RV-6A with a Lyc. If it had a Wankel, cowl would look ODD. Like most planes designed for front engine that "pulls" airplane, radiator is hard to do, requiring space you don't have, adds weight and drag. Air-cooled is efficient, light, simple. FUEL EFFICENCY, drinks fuel, very poor power to fuel economy ratio. It is baked into the cake, inherent design disadvantage.

[@WilhelmKarsten]

Wankel engines are BAD... these inefficient engines are inherently unreliable and cannot pass even the minimum reliability requirements for FAA or EASA airworthiness certification..

[@Flies2FLL]

So you put this small, lightweight, smooth, powerful engine in place of a reciprocating flat 4 and everything is just hunky dory huh? Think again. There is a hell of a lot more to the story folks!

[@WilhelmKarsten]

No Wankel engine has ever been reliable enough to pass a reliability test for FAA or EASA airworthiness certification. It is illegal to install a Wankel engine in any certified passenger aircraft because they are too unreliable!

[@RichardLewisCaldwell]

Weight is less important than efficiency. A Cessna 172's engine weighs 260 pounds and its 56 gallons of gas is 347 pounds, for a total of 607 pounds. An engine with half the weight and twice the fuel consumption is 130 + 694 = 824 pounds at takeoff. Yuck. Consider another way forward: an engine that weighs twice as much per displacement but is twice as efficient. The doubling of efficiency means half as much displacement is needed, so engine weight remains the same. 260 + 174 = 334 pounds and a whole lot smaller fuel bill. And even if above 'sleight of logic' is flawed and the total is 607 pounds, who wouldn't want to pay half as much for fuel? Besides, planes are perfect for hybridization. Look up Nasa's X-57 Maxwell project. A hyper-efficient engine that fits in old engine bays could be augmented with retractable electric propellers on each wing. 2:57 "fewer moving parts" isn't terribly relevant when it comes to durability. Engines have lots of parts that have been engineered to the point that they don't cause failures, which means they don't count in the post-shakedown analysis. And piston engines that are run for long durations in optimal conditions simply don't break. Engines degrade during warm-up and during demanding situations, but a properly-maintained piston engine that is used for long durations at a time can drone on forever. Piston engines love 2700 RPM. Your conclusion is correct: Wankels won't rule the skies. Thumbs up. If you'd like to see the engine I designed, the near-Carnot, just let me know.

[@sandervanderkammen9230]

And then there is also that pesky little problem with Wankel engines not being able to pass the reliability test for FAA airworthiness certification.

[@buckaroobonsi555]

They make terrible power at low rpms. They are not fuel effecient. They are not emission friendly. You would have to either make one that is huge or that has a large number of rotors to make low rpm power. I love their small size but not great in a daily driver! So not at all the perfect ICE for aviation. So like you said reduction drive definetly needed as you pointed out.

[@WilhelmKarsten]

*The fatal flaw in the Wankel engine is they cannot meet the minimum reliability requirements for airworthiness certification.*

[@bhi7165]

Rotaries are very fuel inefficient.

[@sandervanderkammen9230]

And extremely unreliable

[@someotherdude]

@@sandervanderkammen9230 so unreliable that Mazda is again putting them in cars.

[@sandervanderkammen9230]

​@@someotherdude*Mazda Wankel engines are so horribly unreliable that they cannot be used in type-certified passenger aircraft.*

[@tirebiter1680]

A Wankel is smaller and weighs less than a piston engine. Is it a POS? Well yeah, but it will give an airplane a better power to weight ratio.

[@WilhelmKarsten]

In applications where size and power to weight ratio performance is critical, gas turbine engines are used as they can deliver an order of magnitude greater power-to-weight performance and reliability. Wankel engines cannot be used in certified passenger aircraft because they cannot pass the minimum requirements for reliability. Even in drones and ultralight applications Wankel engines do not offer any competitive advantage.

[@countryjoe3551]

A Wankel will require a prop speed reduction unit and a liquid cooling system, negating much of the weight advantage.

[@DoktorBayerischeMotorenWerke]

Aircraft that require high power-to-weight ratio performance are fitted with turboshaft engines

[@aaronfreeman5264]

You can reduce the weight to horsepower by two, easily.

[@WilhelmKarsten]

But you can't fix the reliability problem... reliability issues is why Wankel engines cannot be used in certified passenger aircraft

[@aaronfreeman5264]

@@WilhelmKarsten I haven't seen any complaints about Reliability, in the puff pieces about Wankels.

[@WilhelmKarsten]

@@aaronfreeman5264 You will certainly hear a litany of excuses regarding the reliability problems... all of them completely untrue

[@aaronfreeman5264]

@@WilhelmKarsten With Practice, we can figure out Reliability. How long did it take, efore the ICE worked in Aviation?

[@WilhelmKarsten]

@@aaronfreeman5264 You seem unfamiliar with the development history of the Wankel engine. The reliability problems cannot be resolved, they are the result of fundamental flaws that are inherent to the design concept. No other ICE has received more R&D effort since the invention of jet engines. All of the experts have eventually reached the same conclusion, the Wankel will always be unreliable

[@josega6338]

A Germany-based investir purchased all Norton and Sachs Wankel Engine production machinery, he purchased also the Trabant 'Leukoplastbomber' factory. I have no idea of what could result

[@sandervanderkammen9230]

Scrap metal dealer.

[@bobcornwell403]

Light, general aviation planes are different from automobiles. For one, there are and always will be far fewer of them. They are also used far less frequently. For this reason, I think they should not have to meet the same emission standards as autos do. One way I have heard of to make apex seals last is to use 2 cycle oil so that they constantly get some lubrication. I think such engines should run on methanol as it has about 40% less carbon in it as gasoline. This should somewhat compensate for the lower efficiency. Another factor to consider is that getting at a light aircraft engine to service (or rebuild it) is far easier than it is to do the same with an automobile engine. A lot of the work can be done with the engine still in the plane. Even if that isn't the case, removing the engine is far simpler. Just unhook the ignition wiring and the throttle linkages, take off the propeller, and then out it comes.

[@sandervanderkammen9230]

Aircraft don't have to meet emissions standards. Wankel engines cannot pass the minimum reliability standards for airworthiness certification. Wankel engines are inherently fragile and weak, they fail quickly in high continuous power output applications like aircraft. That is a false myth propagated by a company selling cheap scooter oil with a picture of a rotor on the label. Wankel engines are 4-stroke and operate most reliably on 4-stroke motor oil. There is no advance to using 2-stroke or using more oil than specified by the manufacturer. Research has proven that the optimum fuel for Wankel engines is gasoline. Wankel engines lack the higher static compression ratios needed for optimum combustion of Methanol or Ethanol fuels. That is not an advantage, in fact Wankel engines cannot be used in type-certified passenger aircraft because they cannot pass the minimum reliability standards for airworthiness certification. Wankel engines are inherently fragile and weak, they lack the durability for high continuous power output applications like aircraft. Wankel engines are an obsolete technology that was a total failure in the aviation industry..

[@DoktorBayerischeMotorenWerke]

Aircraft engines are very different than automobile engines.... they must endure incredible punishment compared to car engines. aero engines spend hours at full throttle, for 20 or minutes at a time, and continuously at high load for many hours, the average auto engine spends about 1% of its total hours under these heavy load conditions. The majority of the life of car engine is at idle, stop and go traffic and speed restrictions..

[@thesep1967]

Dets vai so meny rrrotaries are out dere in awjation ...

[@fatstrat772]

Wouldn’t it have to be geared down

[@LetsGoAviate]

Yes explained here 5:27

[@TyReSeDuJuaN]

They will be more strict with emissions in aviation and it won’t last 😢

[@DoktorBayerischeMotorenWerke]

No one can fix the reliability problems, apex seals are inherently fragile and weak.

[@mm-il8dg]

But apex seals has longlife compared to aviation standers

[@WilhelmKarsten]

*Absolutely false!* *Apex seals are so incredibly unreliable that no Wankel engines have ever been reliable enough to pass a FAA or EASA airworthiness certification test.*

[@DoktorBayerischeMotorenWerke]

Wankel engines are not reliable enough to receive airworthiness certification for passenger aircraft, the Apex seals have a MTBF that is too low. The primary failure mode of all Wankel engines is compression loss due to ablative and high brisance damage to the apex seals,

[@josephcalvosa8272]

they are self destructive and fail . imo

[@jamest.5001]

The only reason i don't think so, is the dependability. Also the emissions the modern revised version seems to be a better choice .. with a 2-3 or4 rotor turbo charged diesel rotor engine designed by liquid piston or what ever they are called. Or even a gasoline version. A smaller rotor engine, with about 12 rotors, or 24 rotors. Using a 65-70 mm wide rotor, with a 300 mm diameter liquid piston engine. Built with s larger offset eccentric shaft. To equal a long stroke piston engine. To develop more low rpm TQ. With 12 rotors firing every 10° of rotation of the rotor. Not sure if the eccentric shaft is the same. This should allow for low rpm operation add a turbo to the mix to improve air flow especially at altitude. A 12 rotor firing like a 36 cylinder piston engine. Should be about 700-800 cc, 1 litre or less per rotor, with a 50mm wide rotor it could limit intake flow so supercharging can greatly improve flow wnd power, using a supercharger or Turbos one per 3-6 rotors to improve low rpm boost. A diesel version would be especially efficient if COMPRESSION can reach about 22:1 then add approx. 20-30 psi to this of chilled air at altitude, with the intake charge being as dense as the atmospheric pressure 5k feet below the sea level. At an altitude of 20k feet using the turbo systen to pressurize the cabin to equal about 8-10k feet, the craft having systems in place to keep pressure with engine failure, possibly using electric compressors to maintain atmosphere pressure in cabin, with a computer system to sound an alarm and halt climb over 12k feet roughly if the cabin pressure isn't available, basically operation similar to jet engines to pressurize the cabin, of course having a slight leak to prevent co2 buildup, keeping freash air available. A 12 rotor engine should Shouldn't develop enough TQ below 3600 rpm to keep RPM around 2800-3000, and s 3:1 or 4:1 reduction gear canbe used for higher performance use. Where rpm can reach 8000+ for short burst, a limit of 10 k , using a variable prop with a 2.5: 1 reduction in a bush plane would be a rocketship, and a contra rotating prop , with the engine revinb to near 7k rpm producing 40-60 hp per rotor without boost, and total 🎉 with boost.. this would be approaching turbo prop power. A 12 rotor 600 hp 450 tq diesel rotor engine. And possibly a 700 hp 400 tq gas version, a rocket ship with the engine weighing less than 400lbs with all systems included. In a 2000 lb empty plane .. this wiuld be awesome

[@WilhelmKarsten]

Wankel engines cannot support Diesel Cycle mode operation, static compression ratios above 12:1 or high manifold pressure. Apex seals are inherently unreliable and have an extremely low MTBF. No Wankel engine has ever been reliable enough to pass a FAA or EASA airworthiness certification. Above 300hp Wankel engines are completely unable to complete with Gas turbine engines in horsepower-to-weght ratio performance, they are also more fuel efficient and have an Order of magnitude greater reliability and durability.

[@jaronvaughn4520]

Rotary engines are NOT superior to piston engines(reciprocating engines)

[@joseveintegenario-nisu1928]

RCEs not superior to reciprocating piston engines, respect to What?

[@pazsion]

everything that applies to piston applies to rotary... but the rotary has fewer parts in most designs. both fail in similar ways when you try to push them which one can run ethanol methanol and water better? hydrogen? 🤔 he covers a lot of the most common beliefs. and reasons for air planes.

[@joseveintegenario-nisu1928]

@@pazsion Wankel RCE is specially suitable for Ethanol in Gasoline mixes, as E5 and E10, pls read SAE paper on alcohol blends by someone linked to Syvaro/ Savkel. Mazda run long ago an 'adiabatic' Hydrogen burning RE. Methanol is extremely toxic, better forget it, perhaps could be accepted for model airplane engines. In full size vehicles, methanol burns without a flame, very dangerous. Wankel have a better power to weight ratio than Reciprocating Engines, fuel Economy is better than 2-Strokes, Mazda proved the best fuel an RCE may need is 80 RON, AvGas is expensive, everyday harder to find, also, those with experience with avionized Mazdas say failure behavior of Wankel being usually more gently, it would deliver some power for a while, allowing safer landing, most reciprocating engine faults lead to an instant, total power loss. Blessings +

[@DoktorBayerischeMotorenWerke]

@@joseveintegenario-nisu1928 Rotary engines were very successful in aircraft, the video is about Wankel engines, the rotary version never saw production. Wankel engine have no advantages over reciprocating ICEs and they have several major flaws and disadvantages

[@joseveintegenario-nisu1928]

@@DoktorBayerischeMotorenWerke You mean WW I Rotary Engines? Not that good, I'd say, be it just for its 'gyroscope' effect. I never wanted discussing it, all my comments are about the Rouleaux triangle shaped piston W Froede from NSU draw from the idea by Felix Wankel, so unpractical it had the Spark plugs in Rotor recess.

[@phoneticau]

because need to replace or overhaul after 800 hours

[@sandervanderkammen9230]

Wankel engines cannot even pass the PFTR reliability test for FAA or EASA airworthiness certification

[@WilhelmKarsten]

Wankel engines cannot pass a 150 hour FAA or EASA PFTR reliability test required for certification.

[@monokheros5373]

a WANKEL is closer related to a TWO STROKE engine then a fourstroke its why it needs to be disassembled and have the apex seals replaced so often PICK ONE Torque or Horsepower ... you do not get to have BOTH its High Torque Low Horsepower OR low torque high horsepower OR Mediocre torque & kosepower BHP BF# not at the crank the "liquid piston" engine IS a wankel engine one of 13 wankel theorized and at the time liquid piston was impossible to make

[@sandervanderkammen9230]

All Wankel engines operate using the 4-stroke principle. Beware of LiquidPiston, it's not a legitimate company, just another scam

[@peceed]

Just mount 2,3 or 4 mazda r-ev Wankel generators and use electric engine with cheap variable speed propeller. Safety by redundancy should allow to get certificate (there are also independent electric motors on propeller shaft). Liquid Piston is provably worse than Wankel in many aspects: it has much worse power to weight ratio and bigger size, thera are also troubles with stackings more than rotors on the same shaft. The simplest disadvantage is cost - it require triple injectors and spark plugs count compared to Wankel.

[@WilhelmKarsten]

Interesting theory, if you could get a hybrid system to pass airworthiness certification without a certified ICE? (this seems doubtful) why not use an existing flight rated APU gas turbine like a Solar T62 or Rover 2EG... they are lighter, more powerful much more fuel efficient, quieter and less vibration than a Wankel and offer an order of magnitude greater reliability and service life... and they don't need Avgas or Mogas which is often not available at your local AFO. Of course the real question is why lug around heavy, inefficient rechargeable batteries that pose a very real fire risk.. and the fact that available battery technology is not sustainable or environmentally friendly as some might claim. My money is on air-cooled, reciprocating engines being around for a long time and Wankel engines will be in museums and history books.

[@peceed]

@@WilhelmKarsten Because we are commenting nostalgia for Wankel engines. But I do not think these turbines are cheaper than serially produced Mazdas. I doubt that they are more efficient under low load and more durable under heavy. If you have 2 engines and small battery certification should be easy. I think the best alternative will be electric engine made from many engines for drones coupled by reductor and array of range extenders for drones. Maybe based on free piston.

[@WilhelmKarsten]

@@peceed Nostalgia indeed, the brief heyday of the Wankel engine ended decades ago. Yes more expensive but all FAA certified engines are extremely expensive compared to a Mazda automobile engine. No need for low power output efficiency in an aircraft application and high output durability of gas turbine engines is unmatched by any other type of ICEs. Certification is very difficult for Wankel engines, none of the dozens of manufacturers that have attempted this have succeeded, no Wankel engine has ever been reliable enough to pass a FAA or EASA airworthiness certification.

[@WilhelmKarsten]

@@peceed Electric motors are very efficient and reliable, unfortunately rechargeable batteries are not and the most efficient batteries available are not inherently stable and pose a risk of thermal runaway. Range and payload for electric aircraft is extremely poor with little potential for significant improvement in performance. Drone engines are by definition disposable which prevents them from ever being a viable option for passenger aircraft. Even the UAV and Ultralight market has shunned the unreliable, inefficient and noisy Wankel, preferring the horizontally opposed reciprocating engines by a vast majority. The US military has phased out Wankel powered drones, the last one still in service has been set for retirement... perhaps it really is time to retire the Wankel engine completely.

[@peceed]

​@@WilhelmKarsten I was referring to very specific accumulator type - sodium ion using "prussian white" based electrolyte, do research. Wankel from Mazda was one the cheapest engines that could be used for light aircraft. It was used in military drones due to its small size that could be integrated with fans, it lost this advantage in electric/hybrid era.

[@andrew6274]

Check for UAVHE rotary engines. Made in Spain

[@WilhelmKarsten]

Looks like just another vaporware investment scam like Freedom, LiquidPiston and Rotron... No FAA or EASA airworthiness certification either.

[@stevenfaber3896]

And still inferior to axial flux electric motors.

[@daledavies2334]

Rotary engines not having the decelerate and accelerate of the pistons and connecting rods does not have the torsional harmonics that recip engines have. In all its racing evets, the Mazda engine has never broken an e shaft.

[@sandervanderkammen9230]

All Wankel engines reciprocate and orbit simultaneously. The Mazda 13b has 2 triangle shaped pistons and a 30mm stroke

[@daledavies2334]

@@sandervanderkammen9230I am quite familiar with the construction of rotary engines and how they operate. The displacement is determined by 3 values; 1: eccentricity, of the eccentric shaft 2: radius, of the rotor 3: width, of the rotor and rotor housing. When I mentioned that rotaries do not have the stop and accelerate forces a piston engine has, they do not. The rotor continues its rotation and varies rotational speed only according to engine RPM changes. The rotor turns at 1/3 the speed of the e-shaft, which helps reduce any stress forces that could be created. A very robust design and light for the power output. With turbo compound they could be quite fuel efficient.

[@sandervanderkammen9230]

@@daledavies2334 The Mazda 13B series has a 30mm STOKE created by the 15mm offset throw of its eccentric-crankshaft. The triangle piston reciprocating left and right once per crankshaft revolution. Any questions son?

[@sandervanderkammen9230]

@@daledavies2334 The Wankel engine has never been robust or durable, it cannot be used in type-certified passenger aircraft because of its incredibly low MTBF. No Wankel engines have ever been reliable enough to pass a FAA or EASA airworthiness certification test. The Wankel engine is unable to compete with reciprocating engines in general aviation and in military and commercial aviation the Gas Turbine engines offer an Order of Magnitude greater power-to-weight ratio performance and infinity greater reliability and durability. Unfortunately the Wankel is much less thermally efficient and rejects much more heat energy out the exhaust, of course the problem with adding a heat recovery turbine or turbocharger is the much higher EGTs Much richer AFRs are required by the Wankel engine to quench the EGTs and those negates any thermal fuel efficiency gains from a turbine. Any questions? I suggest you go study some more

[@daledavies2334]

@@sandervanderkammen9230The rotor does not reciprocate left and right. The rotor bearing follows a circular motion around the e-shaft. Thre rotor and stationary gears impart a 1/3 revolution of the rotor as the e-shaft makes a full revolution. The apex seals follow the epichotroidal shape of the rotor housing inner surface. No reciprocation involved. Any questions sonny boy?

[@Juan-oy3fo]

Ar1 10r. Ar1 10r

[@philipfreeman72]

anti gravity propulsion is better & has been on Earth since 1954 , per Dr . Steven Greer .

[@kondeamani5106]

Only the liquid piston rotary has the potential to make sense as light aircraft engine

[@sandervanderkammen9230]

BEWARE OF LIQUIDPISTON It's not a legitimate company. LP is a fraudulent vaporware investment scam

[@someotherdude]

They don't have the durability. It's an interesting engine for sure, but I think tough to produce. That hollow crankshaft? I don't like it. But great for certain niche purposes.

[@sandervanderkammen9230]

@@someotherdude You would have to be very gullible and niave to believe that LiquidPiston is legitimate

[@someotherdude]

@@sandervanderkammen9230 You're really a strange guy with a strange take on the world. Because there is no doubt whatsoever that LiquidPiston is a legitimate company, and they are very likely to find some niche applications of their engine.

[@sandervanderkammen9230]

@@someotherdude *PROVE IT!* *I have found zero evidence to support that LP is anything more than a fraudulent vaporware investment scam*

[@josega6338]

GM had a NSU System Car Rotary Engine good for 750'000 km. Mazda RX-8 Renesis was considered a 1300 cc Engine in Europe; although it largely met the CO and HC standards, its CO2 emissions were in the range of a 199 HP, 2600 cc engine, Renesis engine was banned because high CO2 emissions. If you remember that after Mazda won the Le Mans 24 h endurance and economy race with an NSU/ Wankel Engine, rules were changed, and RCEs no longer allowed to run Le Mans, you may have an image of what is happening. Even if anyone making Reciprocating Engines could switch to RCEs, concurrency restriction measures seems existing in the war against Wankel. Torque is important in Street Vehicles, in Aircraft, Top power and Continuous power output is the need. Mazda proved many decades ago that 80 RON gasoline is enough for Wankel; in the days of expensive and hard to find AvGas, this matters. To reduce seal wear, and as safety measure, experienced Wankel users always add 1 % lubricating oil directly to fuel. The Le Mans winner Mazda RCE had MoS2 additive in Oil, LiquiMoly indicates 1 cc of their MoS2 additive per litre of gasoline/ oil mix. Try a Wankel, compare, and if you find something better, get it! Blessings +

[@WilhelmKarsten]

Please stop posting lies and ignorant misinformation about a topic that you are completely unqualified to discuss intelligently!!!

[@josega6338]

@@WilhelmKarsten Sorry, your terror style is known from long time. I'm a SAE member. Hit the road, young guy, and don't you come back no more, no more, no more...

[@joseveintegenario-nisu1928]

R U located in the Netherlands, mr Karsten? Same as the Orange, who made crimes in Spain to protect the bonds of KLM with Air France, who are enslaved to Buckingham and the City, soon you'll be way down below the Ocean, from Ice thawing, global warming, triggered by the insane avidity of your oil Industry and the financial system behind it. You have no future! God save the queer!

[@WilhelmKarsten]

@@josega6338 You sir a A FAKE AND A PROVILER... please stop spreading ridiculous misinformation about a topic that you have absolutely no formal education or professional experience in.

[@WilhelmKarsten]

@@josega6338 YOU ARE A FAKE

[@andrekemp5059]

Great video. Jes my same question. Same as the Toyota Lexus V8 engine for aviation application. I have a feeling the aviation world is controled by a mufia, monopoly. International Civil Aviation Organization. Plan the future of products and Money made finantial Profit made of products in airplane airplanes. Thru Reg

[@sandervanderkammen9230]

The truth is the average automobile engine is simply not designed to handle the conditions found in aviation. Your average production car would struggle to complete the 24 hours of Le Mans at a reasonable speed. The FAA requires a minimum test of 150 hours at full power with no significant loss of power. The cost to redesign a car engine to pass the certification test is spread out over very few engines compared with cars which are sold in the millions. This explains the higher cost for aircraft engines and why so few car engines become aircraft engines.

[@andrekemp5059]

@@sandervanderkammen9230 Jes that I understand. But Toyota dit redesign that spicific V8 to run at 80-90% max power and rpm. 180kw+- I have looked at the research.

[@sandervanderkammen9230]

@@andrekemp5059 Did it receive FAA airworthiness certification like Porsche and Mercedes-Benz did???

[@andrekemp5059]

@@sandervanderkammen9230 Jes TOYOTA LEXUS YAMAHA 1UZ-FE 1UZ-GE FAA US Federal Aviation Administration Production Approved FV2400-2TC twin turbo 360hp For Airplanes. Boat inboard Toyota Epic S2 1998 Epic S22/SX22 1999-2001 Epic X22 2001 Ambulance Lifesaving Toyota HiAce HiMedic Race car engine SARB MC8-R LE MANS 24HOUR

[@sandervanderkammen9230]

@@andrekemp5059 What is the BSFC performance and cost vs. a comparable Lycoming or Continental engine?

[@mattdavis9642]

Several of the issues for rotary engines have been fixed, thanks to the Aussies and aftermarket. What needs to be seen as of now is lots of hours on a run stand in aircraft configuration. Pop-pooing some of these different engine types without answers to the designs. Like DB would design an engine then continue development to make it reliable. Statistically speaking, a more traditional design can have a failure rate in comparison especially after maintenance. Especially in General Aviation, answers through development is needed, not the average armchair quarterback comment of “it don’t work right”.

[@WilhelmKarsten]

If that was true? Why is it that not a single Wankel engine has ever passed the minimum reliability requirements for FAA or EASA airworthiness certification??? Wankel engines are inherently unreliable and there has never been a solution to this fundamental design flaw

[@mattdavis9642]

@@WilhelmKarsten The biggest issue in this conversation is people’s ignorance. There are definitely two rotary engines being offered at this moment by Diamond Aircraft and both engines have been approved. Adding, there have been others in the past but unfortunately, like so many other companies in General Aviation, have fallen to the wayside due to financial difficulties. I wasn’t trying to start an argument or hurt anyone’s feelings, but folks really need to start keeping up with information on technology and design, and stop relying on rumor and conjecture.

[@WilhelmKarsten]

@@mattdavis9642 Indeed, you are very confused and misinformed regarding this subject. There are no FAA or EASA certifed Wankel engines currently available for General Aviation use. No Wankel engine has ever passed the minimum PFTR reliability requirements for airworthiness certification. Apex seals have repeatedly proven to have inherent issues that are revealed by MTBF testing. This was discovered many years ago by the largest Wankel Aviation development program conducted by Curtiss Wright in partnership with the FAA and NASA. Any questions young man?

[@sandervanderkammen9230]

Nothing regarding the Wankel engines' reliability problems has ever been "fixed" It's called a PFTR test... aircraft engines are run in test cells for hundreds of hours at max rated power until they run repeatedly repeatedly without failure or loss of power. Wankel engines cannot pass these tests. Diamond Aircraft no longer makes engines... They use engines made by German company *Thielert* and are based on production Mercedes-Benz automobile Diesel engines.

[@mattdavis9642]

@@WilhelmKarsten Ok, I see what is happening. You are correct, the information you are relying on was “YEARS AGO”. As for FAA approval, we all know how on the ball the FAA has been especially in recent years. I apologize for not including government oversight in a conversation about advancements in technology. I’ll try to be more clear about the original topic of reliability through development. Most of the issues with the rotary engine or “Wankel” rotary engine have been addressed and has been approved by several countries to include Australia, the U.K. (That’s more then one country) and several other countries in Europe. The rotary or “Wankel” rotary engine can be used under the experimental clause in the states to prove this advancement in this technology. How can so many people and countries be wrong, and you and the FAA but right? I will provide the information to assist the elderly with self education. This will help in an official capacity in understanding when private citizens, companies, and even government agencies continue to develop or assist in development through funding said continuing development how things can change and get better. DiamondAircraft.com - Taken directly from Diamond Aircraft’s website: “The AE50R is a single stage rotary engine that generates 41 kW and is the only rotary engine worldwide that is certified according to EASA Part 22 Subpart H on today‘s market. The remarkable power-weight ratio (2 hp : 1 kg) makes it the ideal engine for unmanned vehicles. With more than 1,400 engines produced, the AE50R has proven its reliability in both, manned and unmanned applications.” This is just one of there engine models they provide. As for most people reading this they will realize and understand that from the beginning I was speaking to fixing or fixed issues with the “Wankel” rotary engine. And I freely admit that I did not include government oversight or felt the need to rely on said oversight in a discussion of what has been addressed and continues to be addressed on a conversation about mechanical issues and reliability. I have provided a company that provides said updated engine on the open market, an agency of the government type that has approved it, and only a matter of time based on continued development, reliable operating hours, and other data to be provided that the FAA will approve. Thanks to the individuals and companies around the world continuing this development, the rotary engine has not only gained in popularity around the world in aviation, but has seen a huge resurgence in racing that will only continue refinement. Unfortunately for some it is more important for them to be right, than to follow the scientific data that may prove them wrong. Thank you Pappy, for correcting me on the importance of government regulation and oversight, no matter how short sighted and antiquated it may be.

[@herbkilian]

Do your homework. I have a 55 hp single rotor Wankel. In my Schleicher ASH 31 Mi motorglider. Made by Austro, pretty reliable.

[@WilhelmKarsten]

*If its reliable? Then why does it not have a FAA or EASA airworthiness certification for passenger aircraft???*

[@sandervanderkammen9230]

The fact that they can only be used in gilders completely destroys your argument that they are reliable.

[@devilsoffspring5519]

Wankel rotary engine don't have "numerous advantages," they have ONE advantage. They are very small and lightweight for a given power output compared to piston engines. That's their ONLY advantage. Piston engine use less fuel per HP produced and it is easier to control their toxic emissions. That's why Wankel rotary engines are rare. For a sports car or small high-performance propeller-driven airplane, they are great. For everything else they suck. Notice that high-performance aircraft all have jet engines and Formula One racecars all have piston engines! The piston engine uses less fuel per HP so an F1 racecar doesn't waste time stopping for fuel. That's it, kids!

[@sandervanderkammen9230]

In aviation Wankel engines have no advantages, their power to weight ratio performance is not better than other available options that are also more efficient and much more reliable

[@devilsoffspring5519]

@@sandervanderkammen9230 Sure it is, it's possible for Wankel engines to produce the same power at half the weight compared to piston engines. Maybe not compared to 2-strokes in small sizes though.

[@sandervanderkammen9230]

@devilsoffspring5519 Reliably? *NO* The new 4-stroke Rotax is better and the Wankel engine is a boat anchor compared to GTs... No legitimate company uses a Wankel engine in a passenger aircraft.

[@LordCakeskull]

I may be uniquely qualified to give an opinion here; I'm an auto mechanic and started my career with Mazda at the launch of the Rx8. 8 years later I moved into aircraft maintenance because my father is a pilot, and I worked at the same airfield as Midwest rotary, so I'm intimate with both Wankel engine and aviation. I believe it is a great powerplant for aviation, and the majority of it's issues are all linked to a common cause which was never solved because of a lack of development in a certain aspect of the Wankel engine in the past 40+ years. They all leak compression internally via the spark plug apertures. I wish I could explain in detail, as I have an engine with the issue resolved running and on the road in an Rx8 (because it was cheaper than renting Dyno time). Maybe I should reach out to get a full explanation video made with someone...

[@WilhelmKarsten]

*_"Lack of development"_** ????* *Your comment reveals someone who has no formal education or professional experience regarding this subject.* *It's as if you were born yesterday or live on some tiny, remote island with a backwards culture???* *How can you get it so wrong?*

[@LordCakeskull]

​@@WilhelmKarsten You'll note that I specified "a certain aspect" in my comment. The specific area of rotary design I was referring to was the ignition side of the rotor housing, which has remained largely ignored since Mazda changed theirs to have a smaller aperture for the trailing plug over 40 years ago.

[@WilhelmKarsten]

@@LordCakeskull *We are not discussing a Rotary engine design.* *The Wankel KKM57 engine is not a Rotary design.* *Utter nonsense son, American aircraft engine manufacturer Curtis Wright was not only the very first to become a Wankel KKM57 licensee in 1958 but was also the first to develop multiple spark plug arrangements and surface discharge ignition.* *Max Bentele is considered the leading expert on Wankel engines in aircraft applications.* *You seem to be completely oblivious to the development history of Wankel engines in the aviation industry?*

[@LordCakeskull]

@@WilhelmKarsten Technically we were not discussing anything; I commented on a video and you involved yourself after the fact. Not that I claimed I was the first to do anything at all. Curtis wright indeed were responsible for a great variety of innovations in Wankel engine design, including surface ignition systems and even multiple seals on each rotor apex But you are being rather ignorant and facetious when you state it is not a rotary engine. The KKM in KKM57 stands for Kreiskolbenmotor which literally means rotary engine in German. Please put the keyboard down for a while and go outside.

[@DoktorBayerischeMotorenWerke]

@@LordCakeskull Anfänger! Your German is an embarrassment! Wrong! _Umlaufmotor_ means "Rotary engine" in the German language. _Kreiskolbenmotor_ translates to "Orbit(ing)-Piston-Engine" Only the _Drehkolbenmotor_ (DKM 54) has a Rotary layout. _Drehkolbenmotor_ translates into English as Spin(ning)-Piston-Motor. Hanns Paschke and Walter Froede completely abandoned Felix Wankle's Rotary layout for the KKM 57 engine, the KKM has a conventional spinning crankshaft and a fixed, non-rotating crankcase/housing... not a rotary engine.

[@ivanivonovich9863]

Why no "rotary engines" on planes... Fuel efficiency, The corner seals will leak, the power is not as high even if using a turbo-charger!

[@sandervanderkammen9230]

There are no Wankel engines in passenger aircraft because they cannot pass the minimum reliability standards for airworthiness certification. Wankel engines are inherently unreliable and less durable in high output applications like aircraft..

[@DoktorBayerischeMotorenWerke]

NO FAA or EASA certified Wankel engines exist... you cannot legally use a Wankel engine in a type-rated passenger aircraft. they are simply too unreliable to pass certification.

[@noelwellstead8744]

Where do I start, ok the biggest problem . The life of the engine eg apex seals and loosing compression and oil consumption. Easy disconnect the metering pump that lubricates the apex seal so you stop feeding sump oil into the combustion chamber that ashes up and now the apex seal has to ride up over the non smooth surface and ware and loses compression due to blow back, Fix by adding two stroke oil to fuel. 2-9000rpm , know wonder the seals wear out . No , the centre shaft has a ratio to the rotors of 3:1 so the rotors at max rpm is 3,000 rpm which is comparable to any aviation engine. 3-Exhaust heat, only a problem with tip ported engines like up to and including the RX7 13b. The RX8 13b is side ported off the rotor which has a much cooler exhaust and with standard oil cooling radiators it is well controlled. 4-Why aren’t more people using this engine for aircraft, well last count about 5 years ago my count world wide was over 3,000 and getting great results which leads me to 5-Mistral Aviation in its hay day specked up a rotary engine and certified 3,000 hrs TBO and an STC into a piper Arrow. Where is the Continental or Lycoming with 3,000 hrs TBO. If you really want to bone up on the rotary check out Rob Dahm on you tube

[@DoktorBayerischeMotorenWerke]

No Wankel engine has ever been reliable enough to pass airworthiness certification for passenger aircraft, the Apex seals have a MTBF that is too low. The primary failure mode of all Wankel engines is compression loss due to ablative and high brisance damage to the apex seals, this scenario is not related to lubrication and there is absolutely no evidence that pre-mix fuel w/ 2-stroke oil has any beneficial effects, Mazda used metered oil injection because research has shown that pre-mix fuel and oil reduces reliability. Mistral is defunct, they went bankrupt after repeatedly failing FAA and EASA _PFTR_ tests for airworthiness certification. No aircraft engine manufacturer has ever developed a Wankel engine reliable enough for passenger aircraft. Rob Dahm is not a professional expert on aviation or engineering, he is not a qualified engineer or certified AMT, he is not even a certified automotive mechanic. You lost any shred of credibility when you listed Rob Dahm as a reference source... Dahm, who is neither an engineer or a certified technician has had his KZbin account suspended for posted videos extolling the virtues of the recreational use of Adderall and cocaine. Please do your proper due diligence before posting bad advice to others that could result is serious injury or death.

[@chadthunderstroke]

It's a great engine, but it's terrible.

[@sandervanderkammen9230]

Too unreliable for aircraft, not reliable enough for cars either

[@brianbowcutt249]

Air/thermal management is what kills the wankel when emissions/fuel consumption aren't a consideration. Lack of intake/exhaust control limits operating ranges/environments and necessitates additional complexity like variable intake runners/manifolds, air injection to manage EGT, and additional cooling considerations for the exhaust/adjacent components and rotor housings that unsurprisingly struggle to dissipate roughly 4 pistons/cylinders and an engine block's worth of heat soaked into a handful of dense components without much surface area and fewer provisions for oil/water cooling channels and jackets. They're also notoriously resistant to hot-restarts, not that any engine finds that state agreeable. The weight savings over modern aluminum reciprocating engines isn't really there either, turbo twin rotors fully dressed are comparable to small block V8's. All those considerations aside, the lack of general technical expertise alone makes them a non-starter, we're long passed the days when most competent small engine repair shops had the tools/knowledge to mess with them. The simpler=more reliable argument reminds me of 2-strokes, more power in a smaller package + fewer/simpler parts in practice means less operational flexibility, less desirable failure modes, and frequent overhaul/service intervals that can only be done competently by like one guy three states over with a six month waiting list.

[@WilhelmKarsten]

What killed the Wankel engine was its lack of reliability. After largest engine development program since the invention of jets, not a single one of the Wankel engines developed by more than a dozen aircraft engine manufacturers was reliable enough to pass a standardized airworthiness certification test program. The Wankel is horribly unreliable as a result of its weak seal design and its poor combustion efficiency, The primary failure mode of all Wankel engines is apex seal failure due to high brisance and ablative damage due to erratic flame propagation and detonation/pre-ignition The Wankel also suffers from poor thermal dynamic efficiency (Heat rejection) and poor mechanical efficiency (low conversion rate) that produces low BSFC and BMEP (low hp per pound of fuel and low torque per liter) Both of which are compounded by the poor combustion efficiency. 26 of the biggest and best engine companies licensed and developed the Wankel KKM57 engine and over a hundred universities and research institutions studied and developed the Wankel for decades. All reached a similar conclusion. That the Wankel engine offers no advantages and several series fundamental design flaws and disadvantages. All agreed that the Wankel is inferior overall to reciprocating and gas turbine engines

[@DoktorBayerischeMotorenWerke]

Starting problems with the Wankel engines is a sure sign of low compression due to worn or damaged seals.. High exhaust, coolant and oil temperatures are all signs of an engine with very poor efficiency..

[@hotliner2872]

The majority of planes want torque (hence the large displacement for relatively low peak power.. the goal is plenty of torque at propeller RPMs), where rotaries can provide power esp if blown, but at high RPMs. So include the risk and mechanical losses of a gearbox, and likely forced induction as well. Perhaps not coincidentally I came here to write this and noticed sonnyhayes already had the same comment below (I am not with Mazda :-), but do have a few degrees in Mechanical Engineering). No offense intended, but this does not scream great-fit to me.

[@WilhelmKarsten]

You should inquire about a refund on those degrees... because if you're not lying they're not worth the paper they're written on son...

[@Allan_aka_RocKITEman]

FWIW: I got into the habit of saying _'rotary radial'_ {rotating radiial aircraft engine} to avoid confusion with _'rotary'_ {Wankel engine}.

[@WilhelmKarsten]

"Rotary Radial" is an _Oxymoron_ An engine can only be one or the other, not both.

[@sandervanderkammen9230]

*Which Wankel engine? One is Rotary and the other is not.*

[@DoktorBayerischeMotorenWerke]

Your comment reveals someone completely unfamiliar with aviation or engineering... inventing your own "slang" terminology is ill-advised.

[@benkasper4035]

Most unreliable engine ever design?

[@WilhelmKarsten]

Without any doubt, the weather man is more reliable than a Wanker engine!

[@someotherdude]

Not even close. Porsche had a disaster with diesels, and Cadillac had a mega-disaster with them.

[@sandervanderkammen9230]

​​@@someotherdude*Lol!!!! You're hilarious lad!!!!* *Porsche has won Le Mans 19 times!!!* *And its flat 6 engines are so reliable that they passed FAA airworthiness certification.* *Even Cadillac made aircraft engines in WW1 and WW2.*

[@sandervanderkammen9230]

​@@someotherdude*Mercedes-Benz Diesel engines are so reliable that they meet both FAA or EASA airworthiness certification.* *You can buy a brand new fully certified aircraft with an Mercedes-Benz engine that came right off the automobile engine assembly line for W168 and W414 class cars.* *Mazda wouldn't even warranty an RX engine in most countries.!*