Taurozzi Pendulum Engine and Why You'll Never See it in a Mass Produced Car or Motorcycle
663,228
Published 2024-01-21
I’ll say it right off the bat. This is a very creative and out of the box design. However being creative, does not necessarily mean that it is capable of penetrating the vehicular market or revolutionizing anything. The first patent related to this engine is from 1974 and the inventor Eduardo Taurozzi worked on the engine and promoted it throughout the 70’s, 80s and 90s and since then it has never been mass produced in a vehicular application, not even a small or limited production. 1974 was 50 years ago. That is half a century. If development started 10 or even 20 years ago there would still be hope, because getting new designs to the market usually takes a lot of time and research and development and fighting to prove their merit and so on and so forth. But 1974 is telling us with great certainty that we will not be seeing this in a mass produced car or motorcycle, probably ever.
But it’s very important to understand the following. The friction between the piston, essentially the piston skirt and the cylinder is very very small in a conventional engine. Remember we’re not speaking about the piston rings here. This engine still has piston rings to contain the air fuel mixture and the combustion in the combustion chamber and these rings are still a source of friction, a much greater amount of friction than the friction between the piston skirt and the cylinder walls. There is no contact between the piston skirt and the cylinder walls. Contact between the two is prevented because a layer of oil is constantly splashed and/or sprayed onto the cylinder wall and the piston skirt then rides on this film of oil.
the piston skirt does still subject the cylinder wall to significant loads. When combustion occurs the major thrust side of the piston places a significant load on the cylinder wall. Load is placed here because of the position of the rod and the crankshaft in relation to the piston. The load of combustion acts normally on the piston and it’s pushing it down. But the rod is angled, the wrist pin is right under the center of this load whereas the rest of the rod is offset from the center of the load. The result is that the rod is trying to flip over. As it’s trying to flip over it pushes the major thrust side of the piston into the wall, However oil is great at resisting loads and if the engine is working as it should this load can never disperse or break apart the film of oil and the piston skirt and the cylinder wall never make contact.
However, this load still creates friction and it’s the reason why cylinders wear oval over the life of the engine. But remember, the life of the average engine in a car is around 300.000 kilometers. Uneven cylinder wear is a problem that has been solved long ago. It does not shorten the life of the engine.
So let’s address the claim, 30% reduced fuel consumption. The friction that stems from the entire piston assembly accounts for around 45% of the entire frictional losses of the engine. Frictional losses account for only 10-15% of the overall losses of the engine. If we completely eliminate the piston related friction than we have eliminated only 45% of this 15%. That means that we have reduced overall efficiency only by 6.75%. But of course it’s not 6.75 because we have been massively over-optimistic here. Our hinge does not eliminate the piston rings and it does not eliminate the wrist pin. So it does not eliminate the 45% friction. Of this 45% piston skirt friction accounts for 12.5% percent, rings are around 22.5% percent and the wrist pin is the remaining 10%. We eliminate the piston skirt friction, let’s assume that we reduce ring friction by half since we get rid of the oil control ring pack and we eliminate piston rocking. We don’t really do anything about the wrist pin. So the hinge more realistically eliminates something like 21.25% of the total friction, not 45%. And this gives us a total potential efficiency increase and fuel consumption reduction of 3.2%.
A special thank you to my patrons:
Daniel
Pepe
Brian Alvarez
Peter Della Flora
Dave Westwood
Joe C
Zwoa Meda Beda
Toma Marini
Cole Philips
00:00 2 solutions, 3 problems
02:41 Skirt friction
08:29 30% more efficient?
11:09 Sealed bearings
16:16 Balance and manufacturing
20:57 Ring torture
All Comments (21)
-
Support the channel by shopping through this link: amzn.to/3RIqU0u Patreon: www.patreon.com/d4a Become a member: youtube.com/channel/UCwosUnVH6AINmxtqkNJ3Fbg/join Further reading: After publishing the video I found some scientific testing of the engine: link.springer.com/article/10.1007/s12206-017-0643-… 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.
-
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.
-
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.
-
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.
-
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 YouTube. You Sir are great! -Cheers from Texas!
-
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.
-
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!
-
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.
-
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.
-
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!
-
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.
-
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.
-
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.
-
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.
-
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.
-
this presenters enthusiasm and clear voice is priceless.. well done yet again .. been following your videos for years
-
Oh shit, I need to change my oil.
-
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...
-
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!
-
Your powers of explanation and argument are never less than intimidating. Thanks for your work. It's always enlightening.
