Twin Rod Avadi Engine - Perfect Balance in a Single Cylinder - Genius or Just Another Pipedream?

[@d4a]

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[@aceman9030]

the crankshaft counterweights are rotating thus they have some angular momentum, but in the avadi they keep revolving means the direction of angular momentum is constantly changing. do you think this could cause extra strain on the connecting rod?

[@MrLince-hr4of]

the solution is a turbo with high boost pressure💥

[@darkwater72]

Regarding the torque spec of this engine, it's not really fair to say it's "cheating" by specifying measuring torque at output shaft instead of the crankshaft. ALL engines measure torque at the output shaft. However, for most engines, the output shaft just happens to be crankshaft. But, that's only a coincidental relationship, it doesn't have to be that way. Didn't various racing bodies change how displacement per revolution was factored when comparing Wankle rotary engines to two-stroke and four-stroke engines? What's the difference?

[@EbonyPope]

If the piston is always rotating so do the pistonrings don't they? Doesn't that mean they will never seal really effectively like in conventional engines since they cannot be broken in? I mean they never run along the same path therefore the grooves it creates will be all over the place instead of fixed position.

[@blarvinius]

Hi, can you please do videos on the MYT engine design, and the Turbocombustion design? kzbin.info/www/bejne/oHK5faCNh52NnK8si=ipxYqG9YrXGWt8Kr

[@michaelbuckers]

It's revolutionary because it revolves.

[@SuperDriver379]

This pun is underrated.

[@okoproroka1561]

So we can call it Revolver

[@BaldurGunnarsson]

@@okoproroka1561 - Or Fidel

[@kevinburke6743]

It gets around pretty well as well!

[@fredk.2001]

It is revolutionarily terrible as well.

[@JavierCR25]

The ICE is truly an amazing feat of engineering. Well over 100 years already and no one’s been able to truly “re invent the wheel” and make a better basic design.

[@andrewahern3730]

Otto cycle* there's tons of other practical ICE designs, most notably turbine engines.

[@JavierCR25]

@@andrewahern3730 they still remain practically unchanged after 70 years

[@super9mega]

​@@andrewahern3730I drive a Prius in one of the coolest things I know about them is they actually use the Atkins cycle, meaning the Prius is one of the only engines on the entire market that wouldn't actually benefit from a turbo. They also don't even have a real transmission either, but that's just a little bit of fun 😊

[@exothermal.sprocket]

I think opposed piston designs that require a supercharger offer a lot of potential.

[@michelarseneau9756]

Wow Thank you very much from the inventor.

[@themortz]

When A Rotary engine and a "normal" Engine love each other alot, the do a special dance and the make this:

[@driftepel]

😂

[@matsv201]

Is this why the engine oil turn white?

[@michaelmceachin1511]

@@matsv201I have never seen engine oil turn white.

[@DumbOrangeFrog]

@@michaelmceachin1511its a joke

[@patricklopes-vtec]

This is more like: when you try to make a direct drive engine inside a differential housing hehehe

[@codymoncrief8478]

I work with a lot of machinery, and one important design flaw is the axial offset between the connecting rods on the wrist pin. When you offset, axially, two opposing forces, you get an inherent twisting action on the arms and a bending force on the pin unless there is a balancing force present. This increases stress concentrations at the corners of the bearing surfaces, increasing the probability of uneven wear. This is only worsened by speed and load. Even on components that sees fewer than ten movement cycles per day, this concentrated load quickly forces lubricants out of the critical areas and results in wiping of bushings, or localized deformation of bearing races. These things would tear themselves apart just from that alone.

[@jbee1086]

I don't see any axially offset opposing forces on the wrist pin. The two connecting rods are bearing on the middle of the wrist pin side by side with equal force and the piston bears on the ends of the pin, just as with a single connecting rod. That said, what I do see as an issue is the piston rotating relative to the cylinder walls and the rings. The sealing rings do not have enough bearing surface or lubrication in the lands to allow them to rotate relative to the piston without excessive wear.

[@innocuouspseudonym509]

@@jbee1086 10:20 seems to show that the cylinder wall turns with the piston. I thought the same thing that you stated until I saw that. I can understand the issue of the forces on the wrist pin but the solution to that is simple: Beef up the wrist pin to ensure it can carry the load.

[@echschmidt]

Correct!

[@monad_tcp]

​@@jbee1086 sealing is usually what kill those designs

[@tolga1cool]

There are so many other issues with this design beyond the unnecessary complexity of course. Another big one I see is the uneven loading of the gears because of the oscillation of the cylinder. Put simply, gears really don't like that. Furthermore a 2:1 ratio is also not great for wear. If at all possible you tend to pick meshing pairs without a common denominator so that the teeth wear evenly across all other teeth and don't have a fixed partner

[@chainq68k]

"All you have to do is position your holes accordingly, and get them to match at the correct time for the correct stroke." ... Engineering is beautiful. Context is king.

[@geemy9675]

two holes in one stroke 😮

[@elios7623]

LMFAO

[@HarbisonelII]

That type of valve doesn't seem great at sealing the combustion and compression though...

[@grifon1981]

That sounds kinda... ghey

[@C.I...]

@@HarbisonelII The exhaust valves are designed for maximum scavenging.

[@CesarOrtiz-zl7eo]

The way you enter and explain the topic of your videos is phenomenal. You introduce it as advertised, make it seem like he best thing in the world, then proceed to explain how it is false and the reason why it is as advertised. then you explain the pros and cons. Absolutely amazing. Keep up the work my man.👍

[@mullayho1759]

Low rpm and high torque is what you need for driving a propeller, and the cilindrical shape with axial output sounds very easy to package in a drone

[@stevie-ray2020]

Plus, the gyroscopic effect mentioned earlier really benefits drone-use by stabilising the aircraft in flight!

[@tartarsauce447]

Yeah it probably can drive a prop directly without any reduction or a set of planet gears at most. And it's shape seems very aerodynamic with very small frontal area. I immediately thought of aviation use when I saw this design.

[@geemy9675]

​​@@tartarsauce447except single cylinder, 15hp...so yeah drones but not aircraft with passengers. what's the advantage compared to jet engines ? I guess noise could be a factor, you can silence the exhaust, but the propeller is always going to be noisy anyway

[@pinospin9588]

maybe good for cropduster or cheap airplane for leisure flying (replace radial engine)

[@Will-sc3hw]

@@geemy9675 cost

[@davebancroft]

In WW2 some engines were made with a service life of just a few hours. Landing craft, for example. Line bored bored crankcases, with no main bearings. My dad's company, Ruston Hornsby, started receiving letters, often in pingin English, from around the world requesting new parts to rebuild them. They developed a kit that could be retrofitted; a new crank with smaller journals and a matching set of main bearings :-) some

[@thepope2412]

This is seriously one of the most educational channels on youtube

[@tuberroot1112]

If he understood the subject , it may help. If you think that, it is because you don't know enough to realise he does NOT know what he is talking about. If it gets you interested , that's great. Just be warned to check what you think you just learnt.

[@clipperwing]

I'm really curious. Could you please point out what is wrong with this video. It seems to make sense to me .

[@arne8158]

@@tuberroot1112 Why don't you give an example of what you disagree with, instead of being so vague?

[@clipperwing]

Sounds like an adhomin attack!

[@colinofay7237]

​@@tuberroot1112 could you point out what's wrong? I don't know thats why I'm asking

[@lsstuff735]

Good idea for a range extender, for it's quietness, smoothness and ability to be packaged with a generator. I could definitely see quietness and smoothness as a pro in a refined, quiet EV.

[@patturk7408]

Finally a tourbillon engine. Complicated enough for a watch but made for an engine....or maybe not.

[@wargamingrefugee9065]

I demand a constant force, silicon escapement watch engine! Tourbillons are too pedestrian for matters of National Security!

[@piccalillipit9211]

THATS WHAT I THOUGHT....!!! We need it on display through a window in the hood/bonnet of the car

[@berkeliumk]

And a skeletonized housing

[@Javierm0n0]

that would actually be so sick. I'd also probably be unable to afford it's inevitable 150k price xD

[@horaciokanashiro-hv2zn]

👍 see my post in the short version 😅

[@d3faulted2]

As a small engine mechanic. I do want to point out that most of the small commercial grade engines are very conservatively tuned. It doesn't take a lot of effort to get them to make significantly more power.

[@kayakMike1000]

What about efficiency? I am always curious if I can beat the power company. With a Stirling engine, coal might beat electricity company

[@wormhole331]

The whole time I was thinking "I wish I had these for my rc planes" didn't think that's what it's pretty much for.

[@koitk]

You can have it in your little RC plane, you just have to join military.

[@NeoIsrafil]

Oh yah, this would be GREAT in one of my rc aircraft... 😂

[@CreeperOnYourHouse]

It would also be great for ultralight.

[@JamesStripling]

A ring gear subjected to all that perpendicular stress doesn't make very good engineering sense to me. Those gear teeth are literally going to take a beating. A bearing surface they are not. For a short lived, compact unit driving a propeller, maybe. That's a lot of machining for a single use engine, though.

[@CreeperOnYourHouse]

@@JamesStripling 1. Yes they were designed for single use 2. Have you ever heard of a Differential?

[@michaelfox1432]

Who measures power at the crankshaft? In vehicles we measure it at the wheels because that's what touches the ground. It really doesn't matter what configuration the engine is or what tricky stuff you did in the transmission, it only matters how much power, torque, fuel economy we get on the ground. For a machine engine we should be testing at the connection point to the tool for the same reasons.

[@ДаниилШибанов-с3ч]

I admire how you explain engine balance every time again and again

[@dahlia_dazol]

In the past he has claimed that it has been explained 16 times, yet I see the count growing even more lol

[@recoilrob324]

He's a classic example of 'Tell a lie enough times and it becomes the truth'. His explanation of secondary imbalance is pure BS.

[@vapenation7061]

@@recoilrob324please elaborate?

[@AZREDFERN]

This would be great for entry level motorcycles. Most are already single cylinder. But all that rotating mass would be pretty stable.

[@nanab256]

21:54 but: -you can make this hole oval or triangle to make surface bigger, you can even extend it to the side wall of the cylinder - there is no obstructions(open valve) in the way - you are not limited by valve lift and potential collision valve and piston, it can be open longer.

[@nilnailscrew4784]

This. He literally made a rotary valve video already. Half the cylinder in a rotary valve is still more space to push air through than a full cylinder of poppet valves since the valve gets in the way.

[@igornoga5362]

While you can extend the valve in radial direction, you can't really make them much bigger in rotation direction because of valve overlap. Popet valve can also be fully open through most of the stroke, while the geometry of this valve design makes it on average half open through the stroke.

[@boam2943]

I thought the same with the addition that I would use only one hole with an external Y to select between intake and exhaust. This way you could have a full quarter hole.

[@nilnailscrew4784]

@@boam2943 I guess the downside of this is that it would induce valve float at high rpm

[@yuuji_]

Just turbo the damn thing to push more air in the cylinder ¯\_(ツ)_/¯

[@anthrobug]

You make it feel like Christmas morning every time you make a new video or I find a video of yours that I haven't watched. And I really appreciate your generous use of representational graphics & animations, it truly helps to understand the physical motions and reactions involved.

[@brooklynwoodard8526]

I would love to see a video about 2-stroke Detroit Diesel engines. I think they could fit well in this series, even though the concept is old. Also, keep up the great work with these videos. Your content is realistic, unlike others that are more like fairy tales.

[@trollmcclure1884]

yeah

[@user-oz5yk9bm5c]

i remember him mentioning the detroit diesel long ago in an old video

[@brooklynwoodard8526]

Do you remember which one?

[@matufujiwara7493]

i think he covered the 2 stroke diesel already in some video.

[@user-oz5yk9bm5c]

@@brooklynwoodard8526 I dont remember, sorry:/

[@Lord.Kiltridge]

I have an interest in ultra high efficiency range extenders. I think there will be a significant market for them.

[@rfwillett2424]

The Motors inherent balance would be an advantage for ultra lights and para gliders. The propeller speed reduction unit being an integral part of the motor would also be advantageous and reduces weight. It also might have the potential of improved fuel efficiency, while being more reliable than two strokes. Those last two points would be debatable, have to wait and see.

[@mandrakejake]

Doubling the number of conrods, adding 3 gears and the complexity of a driven housing seems unlikely to me to benefit power to weight ratio. Rotary valve heads have never worked for long either. If this was a forced induction 2-stroke it may make more sense.

[@geemy9675]

​@@mandrakejakeyeah if rotary valves worked we would use them everywhere in 2 and 4 strokes. pressure in the cylinder ~150 at the end of compression, then ~1000psi at peak pressure. if your valve is about 1si that's like 1000lbs hammering on your rotary valve 7000times per min while it's rotating, always in the same spot + heat. poppet valves in a 4 stroke have a huge advantage. they are fixed during the whole compression and expansion phases, where the cylinder experience the highest oressure phases and pressure only improves the seal that they are making against the valve seat. rotary valves that can seal properly while not adding a ton of friction and wear....

[@mandrakejake]

@@geemy9675 I think they missed a trick not making this a piston port since the piston rotates

[@geemy9675]

@@mandrakejake not sure how a piston port could open / close the volume above the piston. in two stroke they only control transfers under the piston

[@mandrakejake]

@@geemy9675 if you're interested Google 'sleeve valve engine' - on them the barrel reciprocate but the piston doesn't. In this engine it would be reversed

[@tathamsvids2095]

Nice that you could find this lost footage. It is always a bonus when you can see how far you have come and what you learned along the way. Growing up on a small lake, I always wanted a sailboat. I did have a small inflatable one, but usually had row boats I took German in High School 89-92 and graduated in 1993. My teacher Frau Ferris was so happy when the Berlin Wall came down in '89. She taught 6 classes of French, but really spoiled her German classes.

[@allenpaley]

@21:45 As a crude abstraction, consider that if the cylinder head could be decoupled from the cylinder itself and allow face-on-face rotation (while maintaining seal), and that if the cylinder head could be rotated with a further 2-to-1 ratio, the intake/exhaust ports could each exploit half a circle, rather than a quadrant. On second thought, that might not work because of overlap. On second second thought, overlap could be an advantage for scavenging! Perhaps it would be necessary to have two port plates in a sandwich arrangement. At the very least the ports could benefit from a surface area geometry other than circular. A 90-degree pie slice comes to mind. I love how your deep technical dives stimulate one's imagination. Keep up the great work! Additional though: Since the cylinder rotates, perhaps wall ports like a 2 stroke could be assimilated into the design. With this novel style of engine where so many rules of convention are thrown away, I think that bizarre and unorthodox concepts must be entertained.

[@hrishikeshaggrawal]

Ah yes, sacrifice the sealing in compression and combustion strokes entirely for better scavenging. No matter how many times the cylinder and piston assembly spin per every combustion rpm, because the air flow is restricted to the same face the sealing for compression and combustion stroke needs, half of the cylinder face's surface area will always be a physically present solid and only the remaining half can be made intangible for the intake and exhaust strokes. Meaning there is no point in having 4-1 gear ratios on the crank and 2 holes in the spinning cylinder head and 4 holes in the cylinder face or instead a 6-1 ratio with 3 and 6 holes respectively, because those holes will need to be smaller than the original 2-1 ratio, 1 hole, 2 hole configurations'.

[@matthewridgeway9250]

My thoughts also.

[@lqr824]

0:02 "This engine is revolutionary!" he exclaims, as the engine completes a revolution.

[@yu6387t3d]

nice one lol

[@evanarnold580]

Well done! This is a fantastic explanation of the MA-250. I had the opportunity to consult for Avadi and built the first run stand stateside for it. Running the engine is so fascinating.

[@BudgeChem]

This is an excellent video. Your closing remarks really sum up why this channel is so good imo.

[@hazardsharp3125]

He really took the right amount of time for this. Most people would have hit one point, wrote the script, and published. But here, we have the whole story, so far ...

[@kingjoecatmcdlxiv2050]

Technically the design is scalable but only to two cylinders, because you could have the two connected at the base, so piston heads facing opposite directions, and sharing the crankshaft between them

[@PanduPoluan]

Correct. But pairs of cylinders can all drive a common output axle via offset bevel gears. That layout _might_ be practical for boats.

[@allenpaley]

@22:25 I think we might be overlooking the possibility of an opposed design. Consider the output shafts facing each-other axially with a differential gear set between them, and in typical differential style, a crown and pinion gear set outputting the product of the two cylinders' work.

[@zorktxandnand3774]

Well then you have the output shaft where you also need to put your in port and exhaust port + spark plug, so you have a space issue.

[@1man1guitarletsgo]

@@zorktxandnand3774 No, the spark plugs and ports would be at the other end. The output shaft is underneath the big fixed gear when the cylinder's vertical, so an opposed design would work. It would be interesting to see a BMW motorbike with this engine.

[@hrishikeshaggrawal]

Oh god

[@MikeJones-wp2mw]

Dude they could totally make a boxer engine out of this. Even just the dual rod opposed crank weights idea could be used without the rotating cylinder to get some insane performance. I bet that in a bike engine could easily hit some insane rpms.

[@AndrewBrenner1]

I can see that any number of boxers could be opposed in a radial configuration. Presuming that they can fit into pi. However, increasing the number of calendars would require a larger and larger diameter for the final drive. I suppose it also changes the slender single cylinder into a fat circle of ladies dancing.

[@EdBowl]

The crankshaft counterweights being offset when viewed from the top of the cylinder is not big deal, not just because the distance is small, but because it causes a torque that is inline with the torque of the engine, which is already not smooth. This could also be balanced out with an opposing cylinder like in a boxer engine.

[@michaelrockwell9691]

Two things to mention. One is a concern of crankshaft oiling due to centrifugal issues. The oil is definitely not going to want to hang out near the center where all the action is located. The other thing is I imagine a turbo setup should take care of the lack of power, since valve duration issues can be overcome with boost.

[@Jo-rz6bs]

If you can force oil through the crankshafts shouldn't be a bother there?

[@michelarseneau9756]

I have work very hard to fix that issue.

[@pvsolutions9292]

Exhaust valve does not need much area, it is supersonic expansion (when pressure ratio > 2)

[@calypsobikes1]

So attach a planetary gear directly to the output shaft and then it can be a hybrid transmission/engine. If you control the planetary gear set like in an automatic transmission you can have different gears on the direct engine output shaft. Giving a complex set of gears with a range of gears. Depending on planetary gearing you could refine this engine to give better output potential like giving the Avadi the racehorse a riding saddle. Not to mention a potential massive fuel efficiency bonus. It seems like the engine weight alone would be beneficial to its output potential, keep it very light and help the fuel efficiency out tremendously. The planetary will have a desired effect on the main output shaft depending on how you hold the planetary gears like in an automatic transmission. In the size of that you could probably get away with a go cart sized drive clutch. So pretty cheap and pretty light to make that engine more powerful and efficient. It looks like a planetary gear could be attached to the output shaft. Call me crazy right now

[@F3udF1st]

First impression; Very neat, I think the form factor is the biggest potential.

[@matsv201]

Longitudinally mounted cyliders was very popular in model aircraft before electric become commonm the main benefit was that you could build a realy nice model wirh not a ugly engine stickning out

[@T3hJimmer]

@@matsv201 Thats where my mind went with this. High power to weight, small form factor, low vibration. This would be perfect for a drone with a long loiter time.

[@geemy9675]

​@@T3hJimmerhave you seen the power to weight is only good when compared to a generator..

[@itsdokko2990]

@@geemy9675 for a very light aircraft that output is hella reasonable, you don't need to have a 1:1 P/W ratio to move a drone thru the air

[@geemy9675]

@@itsdokko2990 yeah I'm just wondering the actual real life benefit vs proven engine. tech that already provide a wide range of power density if you bring down reliability/lifespan requirement to the level of rotary valves you can also make a lot of power in a small package with traditional engines

[@biscuitsalive]

With the intake and exhaust, you could have the holes be almost a full 1/4 though, they don’t need to be circular, they could be “pizza wedge” shaped. That would up the area a bit at least. They don’t need to be circular as there is no valves pumping in and out. If they could up the breathing just a bit it does seem like a good option for single cylinder motorbikes. Small sized, low weight, low vibration... especially for non race off road bikes, eg. Dual sports or off road work horse bikes.

[@jacobcoughlin2408]

A reporter asked Thomas Edison if he was ever discouraged during the thousands of revisions that occurred during the creation of the light bulb. He answered "no not once, those failures were necessary. I don't think of them as failures. Instead I learned a thousand different ways to not make a light bulb" Remember that humans learn NOTHING from success. We only advance our knowledge when we fail and either physically or emotionally get hurt. Don't be afraid to fail. Be afraid to succeed without ever failing.

[@bojik2616]

If they make it a "boxer" style with pistons rotating "opposite" in unison on a combined output shaft, i can see them making a 2 cylinder, but no more, reasonably. If they boost it, they might offset the breathing limitations.

[@morgan5630]

Dude, this is the single best video of yours I have watched, your ability to explain complex mechanical principles is FAR better than ANY of my college professors. Also, the Avanti actually, genuinely looks like a good design.

[@RedstoneNG]

thats what in saying

[@rabiatorthegreat6163]

With emphasis on the principles, not so much the math part. But that is OK, once you found something interesting you can go and do further research

[@ametti000]

Learned more about traditional balance shafts than this dream motor with a crankshaft that is only supported on one side, that will never see production

[@0N3T1tan]

You are a great teacher! I don't think I ever would understand this stuff without you.

[@GordonWrigley]

I really appreciate that you both explain well the workings of the engine and then give what seems like a very fair and balanced view on it's usefulness.

[@williammurray4584]

Your ability to explain engineering principles is superlative. You should have a series of all your favorite videos put on “The Great Courses” library. You are like the Neil Degrasse Tyson of engineering and gearheads! Please always make these videos!! They are amazing!

[@JohnShelemey]

I think more development is needed. I think the ring and Pinon gear angles should be reversed to handle rotational force better with thrust washer on outside of pinion gears.Olso two of those engine could be mounted ring gear to ring gear.Out of phase by 180 degrees.With traditional ring and pinion gearing between the two engines making the output shaft.I think it should run pretty smooth. Valves are still a problem. Intake and exhaust could be machined as aposing velocity stacks or on angle helpful with rotation direction of the piston.Smaller displacement pistons on each side would decrease rotational mass increase max rpm and help Intake and exhaust due to smaller area within bore and stroke.This has potential at be the smoothest running utility engine. Congratulations to design team. As you already know don't listen to people that tell you what is wrong with your design concentrate on what make it better. Innovation is deficult. Remember 97% of people that want to see you fail live in their mom's basement. They deserve to feel safe.good luck.

[@IGMWN]

Many of your videos are pretty accurate, but this is another one that I have some issues with. The biggest issues I have is at around 19:30 when you are explaining that the output at the crankshaft is not the output at the crankshaft because the engine uses gears for timing instead of gears and a chain for timing. This engine will have a power stroke every revolution on the crankshaft vs a conventional single piston engine having a power stroke every two rotations of the crankshaft, however, the power stroke for this engine will only be effective for about 90° of rotation vs a conventional single piston engine at about 180 degrees of rotation. This engine will fire twice in 720° of rotation on the crankshaft for about 180 degrees of power output every 720° of rotation making the comparison between the two engines very similar.

[@WSlopeAggie]

Not to mention that the horsepower calculation seems to be off, I got 19.4hp at 7k RPM. So, clearly, 15.8hp at 7.4k is either wrong or I'm wrong, but I assume the former. Fairly minor in the grand scheme of things though.

[@timothyearp631]

It might be a good candidate for other applications that require compression, like air compressors or air conditioner pumps. The valve idea is novel but has the same issue that rotary engines do

[@Drunken_Hamster]

I still think it's advantageous and has plenty of potential. If they let David Vizard manage their cylinder head, combustion chamber, port, and timing design, it could make substantially more power and torque than it currently does while retaining the other benefits. I'd love to see a boxer twin or cross-plane boxer 4 version of this (with DV's help) in the 800-1200cc range on a motorcycle or small airplane. *EDIT:* Okay, so technically speaking "all of the bore area for breathing" is a misnomer. Even with 4 and 5-valve heads, only 60% of the actual area is taken up with poppet valves. This is an inherent flaw with poppet valves, but the Avadi engine doesn't use them, it has ports, instead, which can be sized larger than they currently are. Hence why I said to let David Vizard take over the head design. There's definitely enough space to get the same valve area as conventional 2-valve heads, which, given the velocity improvements at low RPM and the magic that David Vizard works on a regular basis, is more than adequate for even a 10,000 RPM engine, let alone the mere 7000 this uses. *EDIT2:* And another thing, isn't the "practical single cylinder displacement limit" all due to balance and vibration? If this solves all of that, wouldn't the practical limit go up to 1200-1500cc, which is reflective of big block V8s?

[@hrishikeshaggrawal]

The practical limit of a single cylinder's displacement has a different bottle neck, which is the piston seals. The volume increases by a factor of cubes but the lining of the seals increases linearly with cylinder size, some extra gains could be claimed with an oversquare design but you get the idea. The problem isn't balance, you usually wouldn't see cylinders above 800cc in even any multi-cylinder engine either, unless you consider the engines for industrial ships and subs but those use much thicker and multiple seals, or such is what I'm guessing.

[@ABaumstumpf]

"Even with 4 and 5-valve heads, only 60% of the actual area is taken up with poppet valves." More would be possible but using circular valves is just the best option overall. "which can be sized larger than they currently are" Not really. Changing their geometry directly affects timings. Making a port larger means that it is open earlier or closes later. And it also has another even bigger problem: they are ports. They simply can not open or close, so instead of a valve opening to fully open and then staying open you have a port that slowly opens and closes gradually (slowly only in comparison). To get an inlet that is open just for say the intake-stroke the port can only cover 1/8th the area. "There's definitely enough space to get the same valve area as conventional 2-valve heads" So no, it can not come even close to that. But it gets worse: As it gradually opens and closes it would on average only be 1/16th the area of the cylinderhead.

[@dmitrykravtsov]

The only reaction possible to this video - What an elegant design!

[@BillHimmel]

What a clever and beautiful design! Don't know if it is practical, but thank everybody involved for trying!

[@lucuspreston7292]

the twisting action between the rods looks like it helps the cylinder rotate. this is extremely efficient!

[@MotoRideswJohn]

The irony of my learning about these fascinating internal combustion engines, during a time in which electric drivetrains are the hot topic, is not lost on me.

[@adrianschmidt5564]

electric drivetrains are so much more simpler. I know that ICE fuels have more energy density than batteries, which is important for aviation, but for anything ground based electric is the only answer in the near future.

[@Galfrid]

Electric has it's own set of issues. Hardly the "only" answer for the future

[@The_Racr1]

@@adrianschmidt5564electric drivetrain with onboard generator and a roof mounted solar panels as back-up

[@drewdemien481]

And of the drive gears aren't forged in a very tight set of tolerances and the gears as well, your failure moment would be in uneven gear wear from said conditions. That's the flaw I saw, but that would have to occur from possibly output drive shaft being unbalanced too or under too much load. Wink. 💚

[@johnrburr]

So the reason for having the piston and shaft rotating, and not the large gear, is simplification of the valve system. Ingenious! Just needs to be adapted for hydrogen now,

[@ЛюбомирДинков]

They already have the rotating sleeve cyllinder. Now they have to learn about Knight, Bristol and Napier engines and they can hone in on the formula. Multiples are possible as a single cyllinder dual piston a.k.a. Jumo layout, just with inline outputs.

[@GodmanchesterGoblin]

Napier Deltic? 36 pistons in 18 cylinders with 3 crank shafts, job done!

[@stephenwestlake7164]

@@GodmanchesterGoblin Napier Sabre. 37litre 24 cyl H sleeve valve

[@GodmanchesterGoblin]

@@stephenwestlake7164 That'll do nicely!

[@TheLowstef]

A compact, lightweight, low-vibration engine for a generator that I can literally pick up and carry with myself sounds like a good idea. Especially if it's as fuel-efficient as "normal" engines. A 5kW generator that I can carry in one hand (and a jerrycan of fuel in the other) can be quite useful in many situations.

[@Endelin]

I was also thinking it would be great for a portable generator. The real question is if it would be quieter than the surprisingly quiet little Honda 2200 watt generators.

[@Bapate-rh9be]

16:00 Not sure: The rocking couple acts on the gears which acts on the large spur gear, and the rocking motion will always interact with the same teeth on both gears. Pretty sure you can tell the additional wear after a while.

[@stevie-ray2020]

True, but negligible for drone-use!

[@Bapate-rh9be]

@@stevie-ray2020 Yes, that is true.

[@geemy9675]

​@@stevie-ray2020this revolutionary engine is only good for army because it costs 100x the price and lasts 1/1000 the lifespan.

[@erkinalp]

Yeah, the differential geartrain is the main wear item there.

[@hrishikeshaggrawal]

@@geemy9675 Its also smaller and thus lighter, meaning more of the entire engine volume is dedicated to the combustion volume.

[@davow8]

Love your clear explanations, great schematics and application of fundamental engineering principles and everyday logistics. Thankyou.

[@popodori]

as always, an excellent review. simply amazing that we get this every time

[@DelticEngine]

One of these would make an incredible 250cc motorcycle!...in terms of smoothness at least.

[@robertescalante9858]

I see huge potential for this engine as a 1.0 to have some form of forced induction. That would hugely help the airflow through the intake. I'm not sure of any system off the top of my head (aside turbos and superchargers) that would help bring the air into the cylinder, maybe something like a 2 stroke setup is coming? awesome video man

[@yorosel3206]

Exactly what I was thinking!

[@annelarrybrunelle3570]

A few things: 1. Essentially you have a single port, meaning single duration, in the head for both intake and exhaust. The differing temperatures may impose a sealing probkem. 2. Duration can be addressed, as several noted, by non-circular shapes for the ports. You're always limited by the area of the port in the rotating head, but the respective ports in the (non-rotating) block can be adjusted in shape, area, and placement. All the induction and exhaust scavenging tricks presently used by other ICEs can be explored. 3. A 250 cc bike engine would still be 2-cycle, yes? Or are those regulated out of existence? Anyway, a 2-stroke, firing every revolution, compares more directly to a 4-stroke of twice its displacement - with a certain amount of apples-and-oranges fudging. 4. NO 4-stroke ICE has even close to half its cylinder area given over to either intake or exhaust valves. And, anyway, we are really concerned with flow through the ports, however achieved. 5. If you are concerned with the RPM of the cylinder itself, I must ask why. It's true there will be some centrifugal strain on tge rings (do they maybe seal BETTER?), and, perhaps more to the point, the pinion gears and their bearings. But metallurgy may be up to the task, possibly for another 1,000 RPM or so at the output shaft. 6. Consider the Napier Deltic, with multiple cranks geared together. That can be a multi-cylinder scaling strategy for this engine (sorta-kinda also evoking the radial strategy of adding cylinders to a single crank throw). Cluster several, say 6, around a central output shaft and connect them to it by spur gears of any ratio you please. Oh, yeah, you can also sandwich an intake/exhaust manifold, with the appropriate ports, between the heads of two cylinders (again somewhat evoking the Deltic) - assuming you started with 1 cluster of 6, you could now have 2, for 12 cylinders, all driving that central output shaft. 7. The potential of scaling using geared multiple units sounds attractive for aircraft redundancy also. If each geared element was connected through an overrunning clutch, several elements could drive a single propeller or rotor (centerline thrust is SO nice) and still provide power if one of them failed, without the yaw attendant a bad engine. FWIW.

[@senatorchinchilla5389]

As usual with these weird concepts, I need it. My engineering brain is tickled. Edit: I just noticed the crank pins are in single shear, whoooo boy.

[@PapaWheelie1]

Good catch- another reason they are suited for one way drones

[@Jo-rz6bs]

Some compressors do it, but Owp.

[@WolfmanDude]

Older single cylinder 2 stroke engines did this all the time. Its not a discrete pin you can take out, the "pin" is one part with the crankshaft. It worked really well in the 1950s, this will be trivial with modern materials and design.

[@SouseMouse]

Now consider the loads on the wrist pin- the cranks are opposed, but off-axis, so they're imparting a rotational force on the piston. What constrains that? The wrist pin. Those conrod holes will go to hell in a hurry.

[@xtnuser5338]

I think there is some internal thing not shown in the animated 3D views. That must be the case. Otherwise those ends of the crank pins aren't even positively located. I mean, the way it's shown in the video, they aren't constrained by anything at all, and when the piston goes up and down they would just flop all over the place. Also notice that the main output shaft isn't connected to anything. The two crank pins must be attached to each other in the middle. Not by just being a continuous shaft though, because of course they need to rotate in opposite directions. Put thrust bearings at the output shaft penetration of the case, let the output shaft continue upwards a bit past those two crank pins, seat the end of each crank pin in a small bore on the side of that output shaft with an appropriate bearing. Or SOME arrangement that is functionally similar to that. Like maybe the output shaft stops short of those pins, and all three are connected with some sort of cast "T" item that's keyed or splined to the output shaft. Whatever, anything that functions that way. Bingo, the crank pins are in double shear, AND they drive the output shaft.

[@MrShwaggins]

You just earned my sub by explaining gear ratios in a way I understood instantly. I honestly could never wrap my head around gearing outside of what it looks like/type but you opened up another line of thoughtfulness with showing it as a lever. I don't know why I never made that connection before. Thank you.

[@Texmotodad]

Did I miss it? I did not see how the "crank" is connected to an output shaft. A BIG thank you for continuing to show us these alternate engines.

[@RadioReprised]

The rotating cylinder is tied to the output shaft.

[@coreobroomstick2739]

@@RadioReprised Exactly.... how? Does the piston turn the cylinder? In the animations, it looks like the output shaft is just magically connected down by the crank somehow. It doesn't really make sense.

[@coreobroomstick2739]

It looks like the crank bevel gears are mounted inside a yoke, sort of like a car differential. The whole yoke/cylinder hybrid assembly rotates on a shaft, which is the output shaft of the engine. At 0:38 you can see some little stub shafts sticking out of the bevel gears. I think these shafts connect them to the yoke. At 1:06 you can see this, it's just hard to determine what is cutaway for demonstration vs. what actually needs to be there for functionality.

[@manualspellcorrect9073]

The yoke (w/ side gears and cyliner) that connects inwardly in relation to the crownwheel, onto the output shaft, is really only shown at 10:04 in the cut-away model. Very frustrating listening to this guy rattle on about this box of gears without explaining how this actually IS connected. The animation just omits it.

[@deslomator]

The last four minutes of this video deserve a longer followup, it was really interesting to see the engineering in its context.

[@scose]

"military funding" is the answer to so many "why" questions in engineering and science

[@appye7994]

At 21:40, I can imagine rectangular shaped slots instead of circles to increase the size of the intake and exhaust areas. The rotating plate could have a shape that corresponds to this. Also, in terms of scalability, I can imagine 2 cylinders facing each other, with two sets of planetary gears going around a double sided ring ... I came up with these ideas from my couch while eating a bowl of cereal.

[@pmcKANE]

Revolutionary engine... pretty sure that most of them revolutionary in at least one regard :3

[@PeteOfDarkness]

New ways of making working design more complicated.

[@boriscat1999]

Very cool. I designed and built a small oscillating cylinder steam engine. The cylinder wiggles back and forth over a hole instead of having a real valve. Very simple design. Old rotary aircraft engines were also very simple. No poppet valves, a whole block with all the cylinders spun with the propeller, and there were holes on the back that lead to the intake and exhaust manifolds. Incredibly simple compared to modern push rods or OHC in a modern engine. Actually getting oil around the engine when centrifugal force flings everything to the cylinder head becomes complicated though.

[@18paulo12]

I was thinking about this engine concept yesterday. What a coincidence! 😅

[@hfyaer]

Happens to me all the time lol

[@CandC68]

A few comments: 1 The piston rotation would seem to increase the friction between the piston ring and cylinder wall. Possibly leading to increased wear. 2- The rotating intake and exhaust port are only at maximum flow when the port full open, align momentarily. As the ports interface starts at a minimal overlap, increasing to full alignment. Then dropping off to the end of the alignment. It would seem the port size and shape would be critical for efficient flow. 3- The alignment of all the parts seem to have no way to be adjusted. With things like valve timing adjustments in normal engines. TDC, dwell, etc would seem to be issues, especially for tuning, and maintenance. 4- This set up seems to have a lot of weight rotating. I love the ingenuity of this design. But feel it would function at optimum performance, only when set up perfectly. And may suffer from components wearing out. ie seals and bearings.

[@luigifranceschi2350]

I disagree on the part that because of higher RPM is more expensive to do it. The engine has no traditional valves, with camshaft and springs. So it can easily run higher RPM because the role of the valves is done but the rotating head, which is much simpler and rotates exactly at the speed of the piston without any possibility of delay or damaging the valves due to overspeeding the camshaft.

[@sicat2345]

nah, it cant do high rpm cuz of the relatively smol portholes. Cant breathe in and out fast enough.

[@luigifranceschi2350]

@@sicat2345 but the same you have on wankel. And they still rev up pretty high. Don’t forget that you can still use in theory up to 1/4 of the surface for intake or exhaust. Which is quite a lot.

[@larsjrgensen5975]

@@luigifranceschi2350 You have a max RPM because the entire engine is also spinning creating a massive rotating mass that wants to rip itself apart. The common tube for intake and exhaust has air in it that needs to stop flowing one way and start flowing the other way 7000 times a minute, so at relatively low RPM the engine is going to stop getting fresh air into the combustion chamber, because it needs to change direction all the time. In a wankel or normal piston engine the air only needs to go from stop to full speed, not full speed to stop to full speed reverse. There is also going to be a port full of exhaust air left in the tube, that needs to be sucked back into the cylinder before fresh air can be sucked into the cylinder, on top of the small portholes problem Sicat2345 also mentions.

[@elsullo2]

@@larsjrgensen5975 "the entire engine is also spinning" Huh?............................elsullo

[@larsjrgensen5975]

@@elsullo2 The crank, piston, cylinder, cylinder head and cooling fins on the cylinder is all spinning around. A outer casing is put around all the spinning things to make it possible to mount the engine to something.

[@delanezdelanez5253]

Just turn the cylinder into the cam. Have the cylinder push a valve the size of the cylinder for exhaust and then another valve for the intake.

[@lake258]

Well it does revolute alright.

[@arturbaginski795]

I designed something like that when I was a kid - the problem with it are twisting forces on the wrist pin and my solution already had the problem fixed, but I'm working on totally innovative engine not using any pistons that will wipe off cylinder engines. It's actually crazy that he did not found out a lot better solution for intake/exhaust - my design had it from the beginning and that was the main goal of my double conrod design...

[@jfdd43]

Seems like a more complicated version of the ‘one stroke’ engine that you covered a few months ago. All these new engines are exciting. I wish we’d start seeing them in vehicles

[@davidheylen2452]

This was an amazing video. Interesting topic? Check. Thorough and intelligent analysis? Check. Clear, easy to understand explanations and illustrations? Check. Fun to watch? Check. Nutritious AND delicious! Keep up the first class work.

[@omegasys8863]

"Sorry man, the gear for your gear for your gear for your piston broke, It'll cost $5000 to fix the $25 part and you have to wait 3 years for us to find one"

[@hashbrown777]

I think this engine would be awesome for gocarts (probably too expensive for chainsaws and lawnmowers) or nitro engines for RC cars and planes

[@vintagespeedshop]

Just one thought. You point out that the Avadi is restricted compared to a conventional engine because you can only use half the cylinder head for ports. Surly the fact the Avadi engine has no valves restricting the port flow and the ports can be made straight, wouldent the Avadi have better flow through 2 ports than a conventional engine with 4 valves?

[@paulqueripel3493]

Do the ports have to be round? Can't they be more wedge shaped, narrower by the plug, wider on the outside?

[@hrishikeshaggrawal]

No matter how you try to change the shape of the holes or their number or the crown-crank gear ratio, having MORE than half the cylinder head's surface area dedicated to intake and exhaust GAURANTEES you sacrifice compression ratio or the sealing in the combustion stroke, which are FAR more important than intake scavenging gains.

[@michelarseneau9756]

When I start designing this engine with friends (we were all working with a F1 engine manufacturer) I can't name it but we had the same visions and yes because the opening have no valve obstructing the ways it become obvious with calculations that even with the opening of a smaller holes it gets enough breading to this engine to perform well at those speed.

[@GetMoGaming]

This is the type of innovative engine design I love. It's beautiful! (@10:07) I wonder what it would be like on two wheels, once the valves are improved.

[@avyfa1946]

Honestly, Liquid Piston engine still seems like the best choice for drones, especially export-oriented and suicide ones. Low amount of moving parts, powerful enough, looks a lot more rebuildable than Avadi and Spanish one, can run on practically anything and have low noise and vibration.

[@michelarseneau9756]

Liquide Piston is in bankruptcy even with multi million financing!

[@mholdner]

A consideration on the valves area is that normal poppet valves are flow obstructions, the intake or exhaust gases have to get around the poppet to get in or out of the cylinder. This rotating plate valve has point in the angle of rotation that has a completely open hole in the top of the combustion chamber with no obstruction for gasses to get in or out. It would be interesting to see some flow numbers on this, versus a four poppet valve head.

[@ludwigreiser4053]

Thanks a lot for the very interesting an critical analysis of this engine design! And thanks a lot for the motivation to create own engine designs - I will immediately start! 😁👍🍀

[@WilliamDye-willdye]

Best wishes on the new engine design

[@ludwigreiser4053]

@@WilliamDye-willdye Thanks! 😅 I will inform you about any progress! 😂

[@paulbriggs3072]

Absolutely IDEAL for an outboard motor with a vertical shaft. Lightweight also. Smooth.

[@peceed]

People don't realise how hard is to beat competent two stroke engine.

[@Madnessnunky]

A rotary valve would work if they geared it differently. Instead of sealing with 50% of the rotation, all you need to do is reduce the rotation speed by 50% and double the holes. It'd be a, "cross" pattern, or two overlapping X shapes. 50% open, 50% closed. Same geometry with doubled space. They could even use elliptical openings, though sealing non-round shapes isn't ideal. There's probably more to it I'm not considering, but it seems plausible. I often wonder why we don't use the same valves for both intake and exhaust. An additional door could handle diverting air flow and that would allow for a single valve almost the same size as the entire cylinder. There were single valve engines historically so it's not a new concept.

[@imweirdimnotsocial]

Thank you for the analysis! It was a very pleasant video!

[@peterduxbury927]

Thanks for introducing us all to this engine concept, and (at the very least), it makes those people who are interested in engines "think outside the square". I could foresee perhaps another failing of the Avadi engine. On the Power Stroke, the two (smaller) bevel gears - will always hit the same spot on the (larger) Bevel Gear. It would be impossible to design a system of gears where the Power Stroke does not hit the same spot! Engine must always have an even number of teeth on those bevel gears. This will lead to rapid wear of (not only the large bevel gear) but also the two (smaller) bevel gears. A future Museum Piece will be the end-result. Also, I would like to think that some (Military) Super Drones of the future would have Solar Panels - all over their surfaces, and extremely lightweight batteries to carry-out their functions more efficiently, during daylight hours. Greetings from Australia.

[@mrwhips3623]

These quirky engines literally never go anywhere

[@martintaper7997]

They do, you just haven't noticed.

[@brizlor]

The simplicity of the valve train opens up the possibility of apposed pistons rather than inline 4 as you suggest

[@shriramvenu]

you could scale the Avadi to a 2 cylinder engine if you put them in a boxer alignment

[@ARKTech49]

One crank will rotate clockwise and other will rotate in counter clockwise if it's in a boxer orientation. Dont know if it will work out.

[@stephenwestlake7164]

But then you would need more gears to get to the output shaft.

[@The_Racr1]

Honestly the scalability is probably this engine’s best selling point. Probably the only engine we’ll ever see that is close to an engine from video-games in terms of scalability. Need more power? Build a mount and slap a second one of these on

[@RichardAbramson-e6e]

Wow. I loved some other of the presenters' videos which are like a whole semester each beautiful clear working graphic models of his engines he's describing and the principles that are involved in creating the engines he's breaking down the small and large technical and scientific issues both of the engine he is explaining about and why they succeed or don't both in part or in whole. Terrific work!!

[@ryanlindley6476]

THERE SEEMS TO BE A MASSIVE MISUNDERSTANDING OF PHYSICS HERE

[@michaellatsky]

?

[@cephyr13]

Great video. I think I have a way to use the Avadi for cars. If Avadi scales to 800cc, and puts one motor at each wheel, the car would have 240 combined hp at ~7500 RPM. Either fix the engine to each wheel so it turns with the wheel (probably not the best idea) or put a CV axle between each motor and wheel bearing. What's nice about that design is that when 1,2, or 3 motors break, you can keep driving. Motor removal for repair would also be cheap and easy. Weight distribution would be excellent with a very low center of gravity. It's like lowering a contemporary engine and spreading its weight to each corner. If you were to combine it with the comprex exhaust to electric supercharger system, you could dramatically increase hp & tq outputs, especially at low RPM, and it would be virtually instant power and super-efficient. That would make for a lightweight, efficient, balanced sports car.

[@Badge1122]

Stupid idea, too much weight and expensive gears. Has anyone though about the piston is being twisted, rods coming from different angle. Piston pin in the rods won't last lone. Do not want one no matter WHAT.

[@theevilcottonball]

As far as I can see, the balance of the Avadi would be possible with a traditional valvetrain. Just have the dual conrods and cranks and connect them using a pair of gears at the front and back of the engine with a side output shaft that runs in parallel to the camshafts and the two crankshafts (this achieves the avadi balance without needing to rotate the cylinder).

[@theevilcottonball]

I should not have commented before the watching the video to the end. You mentioned that they are considering a different valvetrain. Ok what other weird engines do you want to debunk, Scuderi split-cycle, Hüttlin-Kugelmotor , 5-stroke engine (I think the Millikan cycle is better), Willimczik, ..., Dynacam,

[@ChristiaanNdoro]

A well done video - I thought I would be fast forwarding a lot because the video is so long, but its actually very information dense and I actually had to rewind at some points

[@samb657]

man, it started so well... thanks a lot for a very educational video, really enjoying your channel!

[@griffonatrix]

The CEO of Avadi is explicitly saying this is for the drone/UAV industry

[@maksimfedoryak]

Then it must be secured at all costs from china/iran

[@henryisnotafraid]

I really appreciate your well thought out and even handed delivery of the information about engines like this and novel designs. Good on

[@technopong]

I love your engine design deep dives, novel or otherwise. Keep up the good work!