Taurozzi Pendulum Engine and Why You'll Never See it in a Mass Produced Car or Motorcycle

[@d4a]

Support the channel by shopping through this link: amzn.to/3RIqU0u Patreon: www.patreon.com/d4a Become a member: kzbin.info/door/wosUnVH6AINmxtqkNJ3Fbgjoin Further reading: After publishing the video I found some scientific testing of the engine: link.springer.com/article/10.1007/s12206-017-0643-x This was done by the Petronas University in Malasyia and they found that the engine was around 4.69% more efficient than a conventional engine. So about 1.5% more efficient than my generalized assumptions (I said 2.1-3.2%, inventor claimed 30%). The main reason behind this is that in the video I forgot to mention that getting rid of the oil also means we get rid of the oil pump and the oil pump accounts for another 10ish % of friction which is approximately another 1-1.5% efficiency improvement which leads to very efficiency increase numbers. Although, I'm not sure about the actual engine the Petronas test ran and whether it had an oil pump or not. Another possible reason behind the increased efficiency in the Petronas test is that small test engines are pretty primitive and basic by modern standards and usually have very high overall friction, hence a greater reduction with the pendulum design . The test doesn't specify what kind of an engine has been used, but university benchmark engines are most often like this. The other reason behind the greater efficiency is likely due to the fact that the tests have only been done at wide open throttle and at 1800, 2000, 2200, 2400, 2600 and 2800 rpm. This does not mimic real world driving conditions and actual vehicle engines are not optimized at 2.5k rpm WOT. But overall, we can see that the efficiency improvement is nowhere near 30%. But something else the test mentions which is very interesting and something I didn't cover at all is a power increase of 6.28 % which occurs because the piston gets increased dwell time on the shorter half of the cylinder which is definitely an interesting bonus. The test didn't observe engine longevity or wear in any way unfortunately. But overall these improvements are still far from sufficient to justify all the drawbacks covered in the video.

[@ehb403]

The diagram at about 9:50 gives ICE efficiency as 30% (with a note that up to 40% is possible). This is at best efficiency, but at best fuel economy most engines get only half of that! The real key to increasing fuel economy is to reduce this difference so that at best fuel economy the engine also operates at best efficiency. Yes, I have that solution, but as you said it's difficult, costly, and time consuming to prove it. -i call my engines Mutable Motors and 450 Hp engines able to get 45 mpg without spiking NOx emissions are possible..

[@Panin2001oca]

Have you considered the potential of the torque being increased because of the better compression stroke angle? (Might be worse, it’s complicated but take some time to think about it). As well as the shortened time for the compression stroke, I don’t know the effect of that but it reminds me of an Atkinson cycle engine or maybe a little like the taste of an offset crank engine. There are unexplored benefits that I will one day figure out.

[@seanandrew2823]

Why on earth would you choose ball bearings over needle bearings for this application

[@jackn.2395]

0

[@MrLince-hr4of]

pls can you made one video wit ALL the combustion engines they exist, because there are so many i dont know all 👍👍 thx

[@Scoots1994]

I used to look at all the various "revolutionary" engine ideas, but every time I looked closer they fell down on complexity, scale, materials, efficiency, lubrication, or cooling. It's still true.

[@Tuppoo94]

Typically these alternative engines try to achieve better efficiency. Sometimes they achieve that, but it's usually only at wide-open throttle, meaning they're only good for stationary power generation. And if you're going to be running an engine at WOT all day long, you're better off with a gas turbine, which can also be used to generate district heating with cogeneration.

[@fitito500]

I have a taurossi in my house, here in Argentina it is very common. It has Teflon rings and is used for Air compressors in medicine because, those Air compressors don't use oil...taorussi tested that motor in a fiat one in the 80's in the panamericana...

[@stephenkeen6044]

The most promising I've seen so far is the Liquid Piston, which should be good in generator or range extender applications. Also possibly military applications such as drones, etc. Maybe even microlight / paramotor use after it's been in production a while so costs come down. It's the only one that I can see actually making it to production in any scale.

[@Scoots1994]

@@stephenkeen6044 No new ICE technology is going to succeed until the media/government acknowledges that we are actually going to need combustion engines in the future. California has banned the sale of generators which is pretty a fundamental job for engines in modern times.

[@5naxalotl]

i love all these nerd ideas ... but the difficulties of solving the problems with ICE ultimately leaves me looking forward to electric motors taking over, and basically having one neat problem of batteries to focus our minds on. imo the ICE industry has been so efficient for so long, that society has mentally suppressed the daunting complexity and disappointing efficiency.

[@juststeve5542]

Couple of things you missed out: - All that 3% of friction you're removed with the skirt... You've probably just put that all back in with the sealed ball bearings! - With the geometry being so essential, what happens as the engine warms up and parts expand at different rates? There's not even any oil flowing to help even it out across the block.

[@jtocher685]

Bingo!

[@tomhejda6450]

The thermal inconsistencies is a good point. Oil is besides a lubricant also a coolant (in the sense of transferring the heat around the engine). Any anyway, one you make the engine, you'll turbo it and return to the need of oil and oil cooling :)

[@nunyabusiness7630]

Not to mention a skirt helps the actual strength of the piston along with heat dissipation which both offer longevity.

[@kennethraisor981]

yes and air compressors have less thermal inconsistencies so another reason to see it there

[@chris993361]

I came here to make the exact same point. I imagine as the engine heats up that curved arm expands out and shoves the piston into the side of the wall.

[@ourback]

The oil not only is critical to the longevity of the bores/rings, but it also is responsible for a significant amount of heat transfer away from the cylinder bores and pistons.

[@Davido50]

Truth. Pennzoil Platinum only in my beloved twin turbo '22 F150 truck. Tribology is a hobby of mine. -NY

[@johncolvin2754]

That weird engine is going to melt🤣 this is so much crap...

[@ralphwarom2514]

Totally. I was thinking this exact thing. We need oil in our engines for the nice heat distribution it gives.

[@alexanderpetrov7027]

I was thinking this. Those roller bearings are not just lubricated but cooled by the transmission fluid

[@diablobrian1]

Oil is considered the primary coolant in Internal combustion engines. Unlike antifreeze it cools the under side of the piston itself. Your coolant only gets as close as the water jacket in the block and heads.

[@Robert-le2zp]

Oh shit, I need to change my oil.

[@Jannis-hj4vm]

be grateful that in your engine, it's only the oil you need to change, not piston rings and ball bearings😂

[@mickelballah]

Oh shit me too 😢

[@KevinDC5]

I graduated with a degree in automotive and diesel mechanics, and have been working in the field for 20+ years now....... and this video perfectly highlights why I subscribe to this channel and why I do not engage in the comments of KZbin. You Sir are great! -Cheers from Texas!

[@dmitri546]

Says the man that engaged in the comments of this video lol Just giving you a bit of a hard time

[@SuperDrobny]

I'm not a motorhead by any stretch of imagination, so why the hell am I subscribed to this channel??? Ah, wait, it's the no nonsense aproach, no sensationalism, and a goddamn good narrator that through his means of enthusiastic naration inspires curiosity in an average guy like me. Thank you and keep it up!

[@d4a]

Thank you so much for that comment

[@verttikoo2052]

Exactly 🥳💯

[@PeterR0035]

Agree !

[@ddegn]

I'm also not a motorhead and I like this channel a lot.

[@thomasgunn5229]

I am a motorhead n all I think of is all of the things id put these weird concept engines into

[@Poult100]

May I just say, I love the way you say, "no". I don't know if it's intentional or just the way your accent carries over but, it has just the right expression to deliver the sense of what you are refuting. Great videos! Keep posting please!

[@internationaldynoauthority693]

"intentional"

[@joshuagibson2520]

No.

[@ericquinn8578]

He does have a great accent

[@Poult100]

@@internationaldynoauthority693 yes, thanks. Just spotted that

[@ChadDidNothingWrong]

He talks like those lizard brothers on Rockos Modern Life lol. (They were my favorite characters)

[@MikefromMOMichaelTurner227]

I am a retired automotive machinist.. I wish I would have had you around back when I was running my shop 😊 I spent many hours explaining things to my customers. Well done 👍 mt.

[@jasonwood7340]

How'd you like to try an overbore on this engine 😂😂

[@MikefromMOMichaelTurner227]

@@jasonwood7340 lololol uh nope 😆

[@larsnordstrom364]

Fellow machinist here, I've never heard of a "curved boring machine" before, have you?

[@MikefromMOMichaelTurner227]

Using 5 axis movement yes. But I never want to see it again 😂

[@Azzatur]

You're clearly for big oil. I stand firm that this engine's design is composed of magic and pixie farts.

[@d4a]

You know too much!

[@GodlikeIridium]

Hmm... Why am I thinking about that scene from fast and furious, where some poor guy gets tortured with oil... 😅😮

[@That_dawg420]

​@@d4a i will deal with him

[@kroanosm617]

How convenient that you choose to leave out the unicorn blood. You obviously don't care about nature if you support this engine.

[@KidarWolf]

This was fascinating. I'd never heard of the Taurozzi pendulum engine, and it truly is magnificently clever in its attempt to tackle the problem of using large quantities of oil. I am very glad that the engine did find a commercial application in air compressors, where it does seem rather uniquely suited. Your explanations of bearings, and oil, actually were incredibly helpful, and you've greatly expanded my understanding of how any engine works with this video - thank you. This is something I have never had explained to me, despite having shelves upon shelves of books about motorsports engineering, curated by a former F1 and F5000 engineer (my own father gave me his collection when I showed an interest and curiosity in the subject). My hobby of slot car racing actually means this understanding of bearings is incredibly helpful to me, as I've recently had an axle bearing seize up completely - my suspicion is that the ball race bearing was insufficiently lubricated by the manufacturer. The cost is that my electric motor experienced such increased load that it ceased to work effectively as well - where most motors in slot cars will last several years, mine failed within two years. I'm now inclined to investigate whether I would find performance gains in terms of longevity in changing some bearings from ball race to roller bearings - the increased weight is less of an issue, since I ideally want weight down low in the car to help with handling and traction, and the change would be negligible due to the tiny size of the bearings involved. Micrograms ultimately wouldn't matter, considering most of my cars have several grams of lead ballast attached to the chassis.

[@Tuppoo94]

Out of all alternative engine types, the Wankel rotary engine is pretty much the only one that has made it into road-going production cars, and even then only in relatively small numbers. The fact is that conventional 4-stroke piston engines are quite well balanced when it comes to power, flexibility, complexity, reliability, and fuel efficiency. These alternative designs may improve one aspect, but they usually suffer in some other area, often multiple areas, such that the end result is worse than using a conventional engine.

[@basketballjones6782]

okay, boomer.

[@InvidiousIgnoramus]

@@basketballjones6782 Literally nothing he said is incorrect.

[@itoibo4208]

@@InvidiousIgnoramus I agree, and they never said it could not be done, just that it has not been done. iirc, even the wankel has pistons that wear quickly compared to a standard piston. In designing things, it is often the case that, with several people all starting out with different ideas, they may all end up with the same design, because that design is the logical end to a set of problems. That being said, I would love to try designing an alternative gas engine. It looks like a lot of fun.

[@Maddoktor2]

@@basketballjones6782 Go back to school, dropout.

[@Demopans5990]

You also have some very niche gas turbine stuff that existed for a very short while. It's mainly the military that uses them for land vehicles these days where the upside of being easy to maintain and generally being able to run on anything that burns outweighs the decided lack of fuel efficiency compared to conventional engines

[@curator23]

The cylinders are machined by rotating the engine about the pivot axis while keeping the boring head stationary. If the bore of the pivot is used to fixture the block, this would guarantee alignment between the pivot and the bore. No CNC required.

[@TigerRacingProducts]

Close. Definitely close. Plus, you are correct, no cnc is required.

[@nathanchildress5596]

But a fixed axis machine would limit the curve and length of the cylinder, which would limit the stroke, the crankshaft, and the torque of the engine unless you went with huge pistons and then the vibrations would be worse.

[@TigerRacingProducts]

@nathanchildress5596 True, except this is nowhere near how it would be done. This is one time when one thinks inside the box 😉

[@firefly8464]

Great video as always! Keep them coming 😁

[@kevbu4]

In case anyone else missed it, the pivot axis the block rotates on would have to be the same axis the pistons will pivot on. This is the comment was coming down here to make. 👍

[@edda4436]

I have been waiting for this analysis of the taurozzi-engine. Now you made it. As allways a fantastc job. Pure fun to watch. Thank you very much. You are a great teacher!

[@anonymous7386]

I'm not a gearhead by any stretch of the imagination, but thank you for how you've explained all this. I've never even heard of this style of engine before, but you've broken it down in a way that lets me see the physics without losing me in jargon. I'll have to check out some more videos; you may have just gotten another subscriber.

[@AnthonyRBlacker]

Thank you for at least giving the man his credit, he did invent an amazing technology. It's wonderful to see that it has been picked up in oil-less compressor applications, medically used. This is wonderful to see his work not to have gone to waste, but hopefully this puts it to rest about car engines.

[@mrkosmos9421]

It's genuinely amazing that this engine managed to find its way into a medical compressor of all things! It might not be what the inventor intended, but he must be proud of such a use But now I'm curious about what you think of the Ducatti Elenore...

[@lithobreak3812]

Yeah, for medical air compressors, removing oil is a big deal even if it doesn't increase or straight up reduces efficiency, because the oil can contaminate the air.

[@killerhurtalot]

It wasn't even used as a "engine" in that application. The compressor was powered by a electric motor. The "engine" was used for the air pump mechanism...

[@d.thorpe2046]

@@killerhurtalot afaik an engine produces power, a motor consumes power.

[@killerhurtalot]

@d.thorpe2046 that's my entire point. It's not even good enough for a "engine".

[@phuturephunk]

@@killerhurtalot It's likethe swashplate pump that's used on excavators. It was originally designed to be a standalone engine, but it didn't find real acceptance until someone figured out that it's much better as a hydraulic pump than an engine.

[@DezMak]

This is the first time that I've actually heard the advantages of planar bearings explained so effectively.👍🏼👍🏼👍🏼

[@-NGC-6302-]

18:30 or so, about manufacturing the bores - the big thing on the left looks like a rotary indexer, which does indeed slowly rotate the engine block. The tool in the mill is stationary. It's actually a fairly simple setup (a 5-axis is far from necessary for this), though it is obviously not as ideal as making a cylindrical bore.

[@advorak8529]

If you replace the piston at the end of the arm with the drill head, you will get the correctly distanced and rotated cylinder basically automatically. Not a difficult setup at all.

[@TimeSurfer206]

Nice explanation on the bearings. And I am rather impressed with the amount of engineering that goers into the piston rings. In praise of Sr. Taurozzi, I too believe his invention, used as an air compressor to deliver guaranteed oil free air to patients, should alone grant him many accolades and much praise. Bought a "new" car one day, 150,000 plus miles, and promptly repacked the wheel bearings. Wife was like, "Why do you always do that to every car we buy?" "Because it's supposed to be done every 50,000 miles, but no one ever does." "Oh. Yeah, I kind of like front wheels."

[@dcy665]

Well done. I had seen a few links from YT about the "pendulum" engine. Today I saw the oil less engine. Then, thankfully, yours. Exactly the correct amount of reality.

[@yellowbiker7286]

Dude, you rock! You don't just copy-paste stuff, you actually explain things in a way that makes sense. Seriously, kudos to your awesome explanations. Keep up the great work! ❤❤❤

[@timothybayliss6680]

Engineering explained needs to take notes

[@kariossyr6018]

​@@timothybayliss6680 That channel is so great too.

[@bob-the-Millwright]

Love the video and I agree with you 99.8%. the sealed ball bearings don't ride on a single point of contact. your cut away illustration of the wheel bearing provides clarity to the geometry of the bearings. sealed bearings in general are great around 1000-1500 rpms running with grease for lubrication (every application has its own requirements). for over that you start need precision bearings with ABEC ratings 3,5,7 etc these get really expensive then there are the ceramic bearings. all these high RPM bearings run with oil lubrication, Oil bath, High pressure oil, oil mist. something has to remove the heat from the bearing and protect the surfaces from wearing. The world of bearings their engineering, geometry is huge, they may appear fairly simple in design! My hat is off to the engineers who have done the calculations for radial, axial and shock loading for bearings. people today have little understanding of how equipment / machinery works, and you do an excellent job of explaining this. Thank you for your videos!

[@Zippsterman]

Yeah, 'infinitely small' is a bit disingenuous for the point of contact, since there will be deformations.

[@semproniodensso3353]

Just something of a year ago I knew split ballbearing existed!!!!!, Some 30 years ago I was wandering about split ballbearings, but these are in existence since 1884!!!!!!

[@rn4039]

Great video, oil also suspends the byproducts that get by the rings so they are removed when the oil is changed. This engine would probably get carbon buildup in the entire crankcase over time. The oil also brings the heat away from the bearing etc. I cannot even imagine how the cam lobes, rockers, tappets, etc get "lubricated" with no oil. Any friction saved with that arm is probably added right back in as new friction in the arm not to mention the added losses swinging that extra thing up and down.

[@Apophis1010]

Nevermind the Taurozzi engine, this video is a great explanation of how oil works in an engine.

[@richardwallinger1683]

this presenters enthusiasm and clear voice is priceless.. well done yet again .. been following your videos for years

[@VinnyMartello]

I can see why this would fail. Me and my buddy did a hillbilly rebuild on his 50 year old in-line six. We reused the original pistons and the cylinder bores were visibly worn. No need for machine tools to figure that one out. We slapped in new piston rings and fresh bearings after running a hone through the bores and wouldn’t you know it runs amazing. Good oil pressure, doesn’t overheat. Idles fine. No way you could do that on this engine.

[@datengineer2174]

I love that this didn't just shut it down but went in depth and explained why it wouldn't work and rather than being vague, you went into detail on its shortcomings

[@zorbakaput8537]

He always does that - that is what makes his channel better than most - he uses engineering and not opinions like so many YT experts.

[@vanomaden]

The world needs more people like you. Passionate, but not opnionated. Facts are presented in an entertaining way. Kudos. Your channel and @FortNine are at the top of my list. Thanks again.

[@cellevangiel5973]

As an engineer, I am impressed by how clear, complete and correct you handle this fairly complicated mater.Top quality and a rare find. Thanks a lot.

[@YodaWhat]

The actual problems with sealed bearings for this application were not mentioned: 1) The large accelerations of the pistons would tend to distort the rubber, pulling it away from the metal and starting to defeat the sealing effect. Grease would start to escape. 2) The rubber seals would overheat, at least on the wrist pins. Then the grease would REALLY escape. As for the pendulum "solving the piston load/friction problem", another way is to offset the crankshaft centerline from the cylinder bore centerline, such the the side load on the piston skirts during the power stroke is greatly reduced. But of course, that introduces other complications, which brings us back to standard designs. There are excellent reasons why the standard designs *_are standard._*

[@volvo09]

Well said. The bearings only work in a "demo" setting, not long term. This wouldn't even outlast a rotary with the worst possible care given to it.

[@reneneron2971]

Great job. A classic example of fixing one problem that really isn’t a problem, yet the solution creates far more problems than it solves. Another issue…the flame front during combustion is also disproportionate across the piston face. I suspect this engine would be very prone to detonating.

[@TMmodify]

I mean I assume you'd devise a stronger engine head and made the engine block walls thicker near the top, because that this design needed was OBVIOUSLY more weight and less balance lmao

[@t60-flying95]

also doesnt help that when he tried to sell the engine to the great car manufacturers they didnt believe it could even work because "latin americans know jack shit about engines (he is argentinian)" but at least it's used on air compressors in applications where the air must be as clean as possible (lack of oil means no oil in air)

[@Channelscruf]

It’s never just one thing. It’s always many things. Well done.

[@paudeluca9888]

A thankful newcomer here. I discovered your chanel as surfing the internet should be -by chance, by accident, when looking for something else I neither should be doing. I am greatly satisfied, most of all, by your engine concept reviews. I've learned a lot and I seldom find the inherent complexity of vehicle mechanics so easily, naturally and clearly exposed. Thank you. I believe that we -humans, or what is being left of them- need an urgent technological revolution. Literally: an up-and-down set of things that changes everything (and it's certainly not AI). One as significative, massive, yet discrete, easy-going and invisible as the bicycle was at the end of the 1800's. It's not much talked about, but boy, what the humble bicycle did for humanity and had for ramifications! It might be out of your chanel's scope, which on the other hand, I don't see too niched nor constrained (truly, a relief), but what happened to the other vehicle systems that not long ago were being conceptualised, funded, marketed and fussed about? How are things going with let's say suspensions, chassies, steerings, gearboxes... tyres!!... and the concept of vehicle itself beyond making donkeys fly and putting AI systems in charge? There was a big fuss about some compressed air motor, as well as about tilting narrow vehicles, steering geometries allowing the wheels to camber freely while tilting... even gearboxes without no gears. What has happened to all that wonderful concept sallad -madly wrong some of them, awfully inventive many others- that could be found everywhere?

[@zizimugen4470]

5:39 so this is why oil is needed. Thank you for explaining so well the things I cannot see and have not seen.

[@henkbarnard1553]

Ass a machinist, your comments on machining are spot on.

[@vincedibona4687]

Ass a commentator, I approve this spelling.

[@Anomic-mo9ji]

Ass a Ass Man, I'm all in this comment.

[@kennethhumphries2930]

Absolutely Excellent! Logical, in depth analysis. No BS. Just the facts - and ALL the facts! Delightful. It fascinates me that the conventional piston/cylinder/crankshaft engine is where it began and remains the best geometry. All these parts moving in all these directions seem to beg for a better way. Yet, as you said, the solutions always seem to create bigger problems. A circular expansion space is uniform, no sealing discontinuities. The crank arm delivers torque. Add a computer, injection, complex mathematical modelling, it's hard to beat. Thanks D4A. - Oh I can see where no oil is good for medical compressed air.

[@KidarWolf]

Absolutely! To really look into the history of piston/cylinder/crankshaft, you have to go back to some of the earliest machines humanity invented - how truly amazing our species is!

[@Doogleraia]

A thing people often forget when they say it doesn't need oil, is the rotational friction requiring it. And for the "linear" friction, it would require some hybrid teflon-ceramic rings for it to be viable, and that would still require a rebuild at a certain amount of km or rather strokes. But how long would that even last? Once every 10km effectively replacing oil change with an engine rebuild instead?

[@nathangamble125]

10km? Do you mean 10,000km, or do you think this engine would actually be so unreliable that it can only go 6 miles before breaking?

[@Doogleraia]

​@@nathangamble125I was being facetious, using a jokingly low number

[@picardcook7569]

​@Doogleraia you were strawmanning

[@russelljohnson6243]

I've said it before, you are a fantastic teacher! Thank you for all you do and thank you for making a lunkhead like me understand these issues! You're awesome!

[@MichaelKobler-yu6fy]

Oil does not only lubricate plain bearings, roughly 90% of the oil flow of your main- and conrod bearings accounts for heat transfer, simply lubricating and separating the journal from the bearing can be achieved by much less oil flow and/or supply pressure, respectively. This is where closed, lifetime-lubricated roller bearings are deemed to failure, they simply overheat. In case you are interested in the inner workings of tribological contacts, have a look at what is called elasto-hydrodynamics (EHD). Modern numerical methods go a long way in predicting loading behaviour, pressures, flow rates, running-in processes and even wear.

[@timduncan8450]

Excellent comments, sounds like an engine engineer talking!

[@MichaelKobler-yu6fy]

@@timduncan8450 Not terribly far off, I do make a living as a numerics guy with said EHD calculations, which is why I always like to spread awareness on the subject (:

[@ordovicicosilurico6799]

The way this guys explains everything , makes me see the video every second , makes the topic very interesting , remind me one of my university professor that all the students were enjoying the calss so much , that the hour passes so fast, Thanks for explaining everything so nice !!

[@erikgranqvist3680]

About skirt friction: engines for things like lorries/big riggs are regurarly driven up towards 1000 000 km - and more - without any problems of worn cylinders/pistons.

[@azlktune]

They have very low RPM. Fast engines have much higher wear. E.g. Subaru engines have wear of piston skirts after about 100 000km.

[@erikgranqvist3680]

@@azlktune it is kind of correct. The wear seems to be fairly different between different manufacturers. Some engines can last a very, very long time while others grind themselves to dust.

[@azlktune]

@@erikgranqvist3680 As I remember the wear in engine is proportional to the square of RPM. So the big slow engines run longer, independent from manufacturer.

[@janeblogs324]

@@azlktune aluminium pistons, laying on their sides

[@johnnydjiurkopff]

​@@azlktunethat's more of a rough average used for standardizing industry practice and insurance policies. true wear depends on a lot of factors specific to the mechanical arrangement and construction material.

[@johnathankrausrig9237]

i love how you put this up "why we dont have it why, why" xD you did not hide your annoyance with that which is something good! Excellent work, as always!

[@kennethhumphries2930]

Here's an idea for a video topic, should you choose to accept it: The Magic Bullet Engine. What qualities must an alternate geometry ICE (or alternative personal propulsion system of any kind) offer in order to supersede and supplant the conventional piston/crankshaft four stroke model that has dominated since the steam engine? Many alternate designs have been and continue to be proposed and developed. Some have even gained traction, so to speak: Two Stroke, Wankel, Rotary(fixed crank/spinning cylinder), Radial, Axial, Opposed Piston, Sleeve Valve, Turbine. More recently: Liquid Piston, INNengine, Six stroke, and the present topic - Taurozzi Pendulum, among others. Many of these engine concepts have had profitable production runs in niche roles. Others not so much. You've covered many of these individually in detail. None of them begin to rival the success of the classic four stroke gasoline (or diesel) design that is ubiquitous. Yet that design has so many frustrating characteristics. It is so complex, containing a blizzard of parts trying to compensate for its intrinsic weaknesses. Out of 720 degrees, only 180 or even less than 90 degrees of each piston's cycle deliver any useful torque, the balance of the 720 degrees only consuming precious torque. Balance is a critical pain in the neck. At power stroke BDC, the exhaust valve opens releasing a large pulse of pressure remaining above ambient. Heat, the source of all the work, escapes into the head, cylinder walls, piston, and exhaust, an unused liability that must be discarded. There seem to be so many Achille's heels, yet no serious challengers have appeared. I'd love to hear your usual exhaustive analysis of why this is, or what a challenger must do to vanquish the champion. The Magic Bullet Engine is a very broad topic. Perhaps it could be bounded and crystallized into a KZbin video length discussion. I'd love to see you do it. BTW, I'm beginning to think about engines in your accent. Is that weird? It's great for you, but it seems weird for me.

[@darthkarl99]

Short answer, something thats good under low RPM continuous load. The traditional private vehicle role of ICE's is a dead tech at this point, too many bans on new sales coming in around the globe in the next 10-15 years for it to be profitable to develop further for commercial purposes. And Goods transport, public transport, and Emergency services are likely to move towards turbo electric drivetrains before eventually transitioning away from that as the alternative tech matures. And in that context nothing new has a hope of getting in over a traditional ICE because it would take so long to come to fruition that the tech would allready be a dead end due to be retired before it's ready to be used on mass. The only thing that might make it in is the current F1 secondary combustion chamber stuff that allows them to get high power and still run very lean. But even that will probably only make it over if regulations come in that force manufacturers to optimise power per unit of fuel burned in the remaining applications much harder.

[@kennethhumphries2930]

@@darthkarl99 I take your point. Agreed we seem to be approaching the sundown of ICE for personal vehicles. But energy storage and distribution issues for electrics might end up pushing those bans farther than 10 to 15 years in the future. Storage technology, infrastructure build out, and environmental effects are not settled issues. The time it takes to come to fruition may also be hard to predict. It would depend on the particulars of a replacement tech or techs. In any case today's simulation and modelling capabilities expedite development. I can imagine that as electrics begin to make a real impact on the market, the spotlight could shift back toward hybrids due to energy density and existing infrastructure for fuels. A low to moderate HP ICE that is highly efficient at a single load point could come in a new geometry that would out perform the traditional. Fuel injected lean burn, as F! chamber or other forms, seem certain to be involved. Hey, maybe fusion will usher in utopia and we'll have peace with AI's in our time. We watch and wait.

[@Flies2FLL]

Ask anyone with a Porsche M96 engine about sealed bearings. You'll get an earful.... [Look up IMS bearing issue] Great video! As I said, someone is always trying to reinvent the wheel.

[@jesusfreakpl]

"not for long :)" 8:30 the "leme educate ya" smile is priceless

[@Pablo_Gallenti]

Very good video, I know pendulum compressors, I have seen them working in pharmaceutical labs, and they really shake a little. But I've never seen a combustion engine running. Thank you.

[@TheRealWindlePoons]

Fascinating video. Many thanks. It was great to see the historic footage of manufacturing the engine bores. I started my engineering career as a machinist (in '75) and identified the milling machine, dividing head and dedicated fixture for holding the casting. You can see the dial plate on the dividing head rotating to provide the feed to generate the curved axis of the engine bore. 50 years ago CNC was both less capable and more exotic (read: "expensive") so seeing this imaginative use of conventional machine shop equipment was a joy to behold. 😀

[@adrianzmajla4844]

Yes I agree, and can appreciate the chart reading and number crunching involved, to get the dividing head feed rate correct.

[@larrywhitesell4139]

Took my 390,000 mile Nissan vg30e engine block into the machine shop recently and very experienced old machine shop owner was speechless for a minute when he looked at the bores and the piston skirts. Virtually no wear. Cross hatches still looked like new on all side of the bores. Piston skirts looked like new. There was ridge at the top of the bores of about .001 or less. This engine had been used hard over the years, pulling a 4x4 truck, usually loaded with tools, over mountain passes in Colorado. It overheated severely once when a mechanic installed the timing belt wrong. It still wasn't using oil when I removed it. Probably didn't need a rebuild but I'm restoring the whole truck so..... Oh well, it will be good for another 400k or more.

[@thatguyoverthere9634]

I feel like it needs to be noted that oil is both a lubricant and a coolant. In an ICE, oil cools bearings, cylinder walls, pistons, cams, etc. Its an important function as it takes heat and moves it heat from the top of the engine and dissipates it over the large surface area of the oil pan and into the airstream under the car. Its a small thing to mention but without an internal fluid transfering heat, the internals of the engine are prone to getting extremely hot eventually. Air cooling the inside could be a solution so long as it's filtered like the intake but a liquid would work better. Also this issue would most likely affect the pistons and the connecting rods due to the potential lack of sufficient cooling and extreme temperatures experienced durring combustion. In AC or other pump applications this is likely not an issue because of the small scale and low load of these systems.

[@deltacx1059]

12:52 roller bearings may be better but even then "sealed" doesn't mean "maintenance free", ive opened quite a few of those bearings and changes the grease because it started to dry out. The rollers need a oil port like that plane bearings to keep them happy though.

[@Pyroteknikid]

You had to mention the wet biscuit piston rings, now my life's work is out in the open.

[@charlesmyers9765]

Also, the very small savings in friction is being offset by an increase in reciprocating mass.

[@azlktune]

Not necessarily. The pendulous lever keeps almost no load, so can be very light. Also only half of it weight effectively moves. In same time you avoid piston skirt, that makes it lighter.

[@jaredlancaster4137]

​@@azlktunethe pendulum lever carries exactly the same load that makes your bore wear into an oval, that seems pretty significant to me.

[@azlktune]

@@jaredlancaster4137 This force is much less then vertical force and inertial force from piston to connecting rod. So the lever can be also much lighter then rod.

[@jaredlancaster4137]

@@azlktune yeah the lever doesn't need to be as strong as the rod, but it needs to be longer, and it needs to be curved. And you still need the connecting rod. The reciprocating mass will be considerably higher.

[@azlktune]

@@jaredlancaster4137 hard to say without calculations. I think it is not critical.

[@timpretzsch2609]

A roller bearing ball contacting a flat surface is indeed a "POINT" of contact, but roller ball bearings are not rolling on a flat surface, they are rolling in an inner race shaped conically. As well as the outer race being conical where it contacts surface of the ball, so the pressure is spread out across a much wider cross section, although it is a curved line from the inside to the outside of the bearing. Although I agree that a ball or roller bearing is not the best in functionality for impact, I thought I would shed some deeper thought on the contact area for pressure distribution as compared to what you described and showed in your depiction.

[@AsmodeusMictian]

I have to say...I normally don't even watch vehicle / engine related videos but I watched this one. You got yourself a subscriber, man. No muss, no fuss, just logic and explanation.

[@TradeWorks_Construction]

Very good assessment as usual, you’re a tried and tried pragmatist and I always appreciate you including why the topic is being discussed along with the social media aspects. When someone has actually invested a large amount of time into not just learning but truly understanding the fundamental principles in action at both the macro and micro levels, it makes them qualified (in my opinion) to weigh in on answering these types of questions that lack pre-existing Independent empirical data. Trolls and haters are 99.99% only capable of commenting because there is an element of anonymity. Having the confidence in the answer you have arrived at and being able to defend it logically/rationally as well as post it as a video open to a sea of criticism is what makes you my favorite channel for most anything vehicle or engine related. Thanks for the strong response, more than anything the fact that the inventor himself has gone silent for the past 12+ years speaks volumes assuming no obvious extenuating circumstances occurred.

[@adrianzmajla4844]

One of the best comments here! Agreed.

[@jdmking4776]

The old intro ❤. I miss it, never get rid of it 😭

[@mortimersnerd9991]

Hats off to Mr. Taurozzi. At least someone is still thinking about this stuff. It doesn’t mean its better, but at least someone is thinking about it. In this case, I think the machining is the big problem. If someone could figure out how to drill a curved hole cheaply, maybe a radial version of this would look cool and be balanced.

[@1crazypj]

In my experience of motorcycle engines, needle bearings will break through hardening of either crank-pin or big end (or both) One of the problems is centrifugal loads at high rpm, which, with experience, can tell you if motor was over revved, dirty oil or had ignition problems. (Harley Davidson are very obvious, over advanced ignition causes wear on top of pin and after TDC, over revving causes wear at bottom of pin, dirty oil, wear pretty much all the way around, plus, can wear flats on the rollers as they skid instead of rolling, inside of big end also shows wear patters) Same thing happens on two strokes and other smaller engines but rpm has to be higher to overload bearings.(Honda had 9,500rpm single cyl push-rod motors in 1959 with only a 'dipper' on big end) Did you mention the extra friction from the extra needle bearing on piston arm? The machining isn't actually too difficult if block is mounted between centers in a dividing head or rotary table, I would guess a circular cutter, single point (fly cutter with round cutting edge) Could it be made with dual cranks and opposing pistons as a two-stroke? (as used by Junkers) A low rpm diesel could use the fuel for lubrication?

[@fredsalter1915]

Outstanding breakdown of this engine that I have never heard about. God bless, d4a and people like Taurozzi!!!

[@linuxguy1199]

Even something as simple as a driveshaft needs lubricant (in the two u-joints), an engine that doesn't need it is a pipe dream. That is if it handles any load.

[@Sir_Cactus]

There are a great number of engine concepts on the internet, some more stupid than others, some would not even work. Would be fun to see you make videos about them.

[@nickrider5220]

Great analysis. Sealed bearings also produce more friction than a non sealed bearing !

[@stephengreen3566]

Thank you for making these engines understandable for the average person.

[@Jupiter-rs4zl]

It has its niche use in air pumps that dont require oil removers for the air and it fills it nicely

[@970357ers]

A video (or a series) on different manufacturing techniques/metallurgy would be interesting!

[@emekauzo5358]

Another amazing video from you, D4A! This is just an honest explanation without any preconceived opinion. Well done!

[@bendordoy4815]

I didn't know that the Taurozzi pendulum engine even existed ver informative vedio.

[@ErikAndersen-pf5yh]

Never thought for one second that your thorough representation of this engine designs pros and cons was meant to be anything other than purely informative. Being disrespectful would be surprisingly out of character 🙂

[@geogineer]

Wow, you are my new go to for breakdowns! You give facts and figures, not just conjecture. You leave no stones unturned, and I just wish I could send you a list of things to break down for me! Please keep going, and please know you're appreciated!

[@k1ll3rvc]

Manufacturing of the bores would realistically be done by designing a machine specifically for that operation, that way it should be able to operate at similar speeds to existing boring machines. This would likely only be done once you get above a certain scale of production though, and would be its own very expensive and weird machine. CNC machines make most sense where different operations are needed so you can swap tools or make different parts on the same machine to save time or space on specialist machines, but for mass production a single purpose tool is pretty much always the way to go.

[@qualcunoacaso4865]

Poor machines, why do you call them boring, at least they try to be funny 😔

[@MrLince-hr4of]

i like depressing reality 🤣🤣🤣 pls more of it !!!! lots of fun 👍👍👍

[@alexfreund9460]

*immediately starts looking for the next oddball engine to beg D4A to explain

[@Blurns]

I've aked about the MYT or Swing-Piston engine before and got ignored.

[@sigataros]

I think there's still potential for this engine, it's design, even though expensive, can extend the lifespan of the engine, in regular engines, the friction from the pistol to the cylinder block will inevitably wear out the engine to the point that you need to somehow replace the whole side of the cylinder block, but with this engine, if use oil bearing on everything else, you will get more possible lifespan, it's not just limited to 300k kilometers

[@hillonwheels8838]

Something that is forgotten about with the oil in an engine is that it is also used for cooling. The oil that is sprayed onto the bottom of the pistons and cylinder wall help to keep the piston from deforming due to the constant build up of heat from each combustion cycle. Very interesting engine design that shows what happens when people are able to think outside the box even if it is not able to be used.

[@jaybeevee6994]

Fantastic video, And I must stress with great stressness that i truly enjoyed it!

[@vincedibona4687]

“I must stress with great stressness” 🤦🏻‍♂️

[@MrDanthemaniam]

I think it's great that you debunk this and I agree with you on everything except for one point. Maintaining perpendicularity and machining the bore in a curve is not that difficult. All one needs to do is bore the axis of the pendulum arms then rotate the casting about that point under a suitably designed cutter head. Conceivably it could be done into passes.

[@maszkalman3676]

if you do it in passes it will be never without any transition scars... so you need to polish that then if the polish it even with a slightest difference withouit a piston ring would make every piston leak a different amonut of combustion gasses so it won't run or you would need exactly sized psitons for every bore that would be no problem right????

[@MrDanthemaniam]

@@maszkalman3676 I'm talking about a roughing pass and a finishing pass. There would be no transitions. The finishing pass would completely overlap the roughing pass.

[@maszkalman3676]

@@MrDanthemaniam Then make a test one and try it out how long it can run and make perfect fit pistons for that you could mke thousand sif not millions of views on that but i don't believe it could ran too long...

[@MrDanthemaniam]

@@maszkalman3676 are you a machinist?

[@maszkalman3676]

@@MrDanthemaniam Machinist no but i work at a lumber mill and since the machines are old we need all the metal components custom made and have to pay a fckton of extra since the old sizes doesn't work anymore after wear we need bigger parts (very slightly) si it's impossible for this engine to run efficiently after the slightest wear...

[@82726jsjsufhejsjshshdjso]

Exceptional quality channel. Trust you completely. Thank you for teaching me so much about engines.

[@d4a]

Never trust anyone completely 😁

[@adrianzmajla4844]

​@d4a This comment shows us viewers the truth, that you are humble, down to earth and honest. You are the real deal my friend.

[@stevesamuel263]

Love the video. Your enthusiasm while discussing engineering concepts is great and stops the video from being a dry lecture.

[@amarissimus29]

Your powers of explanation and argument are never less than intimidating. Thanks for your work. It's always enlightening.

[@tomhejda6450]

One thing worth mentioning thaz when you remove oil, you remove also the oil pump, which also causes a bit of a mechanical loss. But with the need to still hace all the other accessories (incl. the camshafts and balance shafts that are completely unavoidable), you're not removing the whole chain/belt complexity, so it isn't really significant.

[@-jimmyjames]

Very much so. Quite a bit of freed parasitic loss.

[@Greebstreebling]

In 1974, I attended a seminar in a hangar at my place of work - AERE Harwell in Oxfordshire, England. The seminar presenter was a chemist and had a four stroke engine running in the hangar which was lubricated by a non oil based additive he had designed and mixed with water. The reason I'm posting about this, is that there's another reason why good inventions never get to see the light of day, and that's because of vested interests. Some years after the seminar, I learnt that the Chemist had been bought out. Guess who by? You got it, a big oil corporation.

[@halsnyder296]

Pretty weird design, love your analysis!

[@canepa1]

Soy de Argentina, conocí a Eduardo taurozzi, trabaje reparando y haciendo mantenimiento en hospitales a los compresores de aire taussem, lo único que puedo corregirte al respecto es que los bloques de motor son en base a metal fundido y la rectificación del cilindro es sencilla con solo una máquina de 2 ejes. Me encantan los vídeos, éxitos.

[@Zenvo-uu9tm]

If anything was groundbreaking and check the boxes for added advantage, efficiency, longevity ,manufacturing costs, etc... car manufacturers wouldn't hesitate to mass produce it ... But as mentioned, that doesn't negate the genius of Mr Tarruzi ... thanks for detailed video

[@teekuang]

Won't the heat expansion affect the lengths of the pendulum arm? resulting side wear to the piston?

[@d4a]

I doubt the arm gets much heat as the crown gets most of it. But we don't have oil now to help us transfer it onto the engine so it's possible, but of course we would need actual tests to see exactly what happens, but a good point still, thanks.

[@allangibson8494]

Cold weather would have a similar effect…

[@dividivus]

I understand the low efficiency gain and all the drawbacks of this design, but regarding the maximum theoretical efficiency gain you forgot to subtract the oil pump losses if is not needed anymore.

[@dividivus]

Also alongside with the sealed bearing and no oil to suspend the blow by combustion products, soot would enter and deposit everywhere inside the engine, thus even less lifetime for the engine.

[@svgPhoenix]

He also forgot to mention the increased friction from all the sealed ball bearings

[@oasntet]

I am baffled by youtube commenters who haven't learned to ignore AI-voiced channels. They're already extremely low quality and full of misinformation, and they're only going to get worse. It's basic media literacy; the more automated a channel's videos, the more likely they are just churning out sensationalist crud full of mistakes, misinformation, or outright lies to get more ad revenue.

[@crispyone2564]

Yeah but shouldn’t an expert expose the misinformation and also educate us and get some KZbin revenue in the process as a bonus?

[@teapot2_1]

For someone so "literate" in media it's just funny you're repeating the "media literacy" buzzword. I'm certain in the next 6 months you'll have a new buzzword to repeat from Reddit.

[@oasntet]

@@teapot2_1Media literacy isn't a buzzword I got from Reddit. It's the name of a class I took in college in _1999_.

[@nicholasagnew2792]

I don't understand why people assume the engineers of billion dollar corporations are stupid, the same people that spend tons of money on Wilwood brakes, cuz the stock brakes have to be crap, they're stock after all smh. Great video man, you're really good at this stuff.

[@markhammer9975]

Just another home run of a video. This channel is that helped me to understand so many mechanical concepts.

[@NewtonInDaHouseYo]

And you didn’t even discuss the asymmetric combustion chamber and it’s impact volumetric and thermal efficiency. All in all an interesting concept but not practical.

[@joels7605]

Boooo! You and your logic and reason raining on everyone's parade.

[@d4a]

Boo I say!!

[@MRptwrench]

Dude, you nailed it. I've been wrenching for over 40 years and I enjoyed your explanations and passion. I'd like to add that material science and design improvements to modern pistons have minimized side loads even more. Radical changes are radical. Incorporating them creates probable faults in manufacturing, parts supply chain, and of course the consumer end. I'd like to use Nissan/Infiniti's VC-T, variable compression engine as an example. Hope I'm retired before they come out of warranty.

[@Sergei_WHY]

Wow, this must be the car channel I've been looking for. What a nice concise explanation of a fascinating design. Nice to meet you!

[@derrickcook1824]

I love this guy finally someone who can explain things the way I think of it.

[@antonywood995]

Very funny host and logical reasoning. There are good reasons why engines haven't changed dramatically. I'm sure designers went through so many possible configurations over 100 years ago, before all settling on the same solution.

[@ramptechtruckcurtains6313]

I love your passionate, accurate, descriptive commentary. Your voice is easy and pleasant to listen to... Even quite humours and definitely educational. The big thumbs up from me!

[@eloryosnak4100]

Man from UNCLE was severely underrated, i hope this gets more love!

[@urielnogales5365]

I love this dude’s no nonsense and comedy to explaining things.

[@hardergamer]

Most 2T use ball bearings and some large CC and HP, like 3.5l+ 350HP+ 2T outboards and most 500-700cc single cylinder MX bikes use BB, but their BB are drip-fed 2T oil.