You'll understand everything about Atkinson, Miller and Otto cycle engines after watching this video

  Рет қаралды 1,438,526

driving 4 answers

driving 4 answers

Күн бұрын

A typical four stroke engine or an Otto cycle engine does intake, compression, combustion and exhaust. The Atkinson cycle and the Miller cycle engines also do intake, compression, combustion and exhaust, however they differ in a small but very important detail which allows them to be significantly more efficient than the Otto combustion cycle. And in this video we will dive back into the history of engines in order to see and learn about the evolution of the combustion engine and the difference between four stroke Otto, Atkinson and Miller cycle engines .
The Otto engine as we know it today was invented in 1876 by German Nicolaus August Otto.
Although it doesn't seem that way the 1876 engine has many of the elements we see on engines today and is Otto's first true four stroke engine. There's a crankshaft, a connecting rod and even a camshaft. Inside we have a piston and the engine does intake, compression, combustion and exhaust just like any modern engine.
Of course Otto's first engine was an instant commercial success and of course Otto patented the design. Now this, the patent, is what brings us to Mr . James Atkinson, who like many of his contemporaries, after seeing the commercial success of the Otto engine, started developing his own engine. Now the catch is that in order to be commercially viable such an engine had to be different enough from Otto's design in order to not infringe on the patent rights.
Now Atkinson decided that the compression stroke of the Otto engine was actually something that could be improved upon, and that was to be done by reducing the length of the compression stroke in relation to the length of the combustion stroke, or the expansion stroke as some call it. In other words the engine would spend more time making power than wasting power on compressing the air fuel mixture.
In 1957 US engineer Ralph Miller patented the Miller Cycle engine. Now the Miller Cycle engine relies on the same concept as the Atkinson engine and that is to reduce the power sapping effects of the compression stroke. The big deal is that Ralph Miller chose a much simpler and much more elegant solution compared to the extremely complicated set of rods and linkages from Atkinson's original design.
And the solution is this: keep the intake valve open longer. That's it. The construction of the engine stays absolutely the same as that of a conventional Otto engine, the only thing that differs is the valve timing. A conventional Otto engine closes the intake valve before the compression stroke begins. This is done in order to ensure that the entire length of the cylinder is used to store and compress the air fuel mixture leading to optimal power output. The Miller engine doesn't close the intake valve when the compression stroke begins. The intake valve is kept open during the first 20-30% of the compression stroke. An open intake valve of course means that the upward motion of the piston simply pushes some of the air fuel mixture back into the intake manifold. The piston can't compress anything until the intake valve closes.
In fact in the late 90s Mazda put this exact concept into practice with their KJ-ZEM engine which they installed into the Mazda Millenia / Xedos 9 /Eunos 800. The KJ-ZEM was a supercharger 2.3 V6 running the Miller Cycle.
Right after the Mazda Millenia was discontinued Toyota revived the concept behind the Atkinson/Miller cycle. Toyota's foray into this field started in 1997 with the very first generation of the Toyota Prius and it's 1NZ-FXE engine. But this time instead of a supercharger we have an electric motor which is used to make up for the lack of torque and responsiveness. As we know electric motors produce instant torque and they don't sap the power of the engine like superchargers do which means that hybrid drivetrains and the Atkinson cycle are a match made in heaven which was put into practice in all of Toyota's hybrid vehicles. Now another advantage that modern technology has brought is variable valve timing or VVT. This makes it possible to run the engine in the Atkinson cycle only when this is desirable, which reduced load conditions such as highway cruising.
Now Toyota's usage of the Atkinson cycle is perhaps the most popular to date, but Mazda definitely hasn't given up and they employed the Miller cycle yet again in a fashion similar to what we have seen in the Mazda Millenia. This time it bears the name Skyactiv-X and in addition to a small roots supercharger and the Miller cycle the Skyactiv X is also the first ever commercial engine to have Spark Controlled Compression Ignition or SCCI.
A special thank you to my patrons:
Brian Alvarez
Peter Della Flora
Dave Westwood
Joe C
Zwoa Meda Beda
Toma Marini
Cole Philips
00:00 The road to compression
08:15 Atkinson
14:05 Miller
18:04 Mazda and Toyota
#d4a #atkinson #enginebootcamp

Пікірлер: 1 346
driving 4 answers
driving 4 answers 4 ай бұрын
100 cars that changed the world: Stem engine model: 1-2-3 count with Car parts: Patreon:
Jububoo Baroo
Jububoo Baroo 4 ай бұрын
Thank you for explaining how single attribution neglects credit to what is often a long collaborative effort. Michelson, Lorentz and Poincare should always be mentioned when Einstein is for example. He gave them no credit and stole their works as his own.
NickShl 4 ай бұрын
You look on Atkinson engine only from one point of view. Thinking that it reduces intake stoke is wrong. Have you touched exhaust pipe? Hot, right? That is because there some energy left. What if we will be able to catch this energy somehow... may be we can make power stroke longer, give exhaust gases more space to expand? But wait! That exactly what Atkinson engine does!
Dangermouse 4 ай бұрын
Thanks for another great video 👌 19:15 I was lucky enough to be working for a Mazda dealer in Australia where we were Eunos agents. We had several Eunos 800Ms that we serviced and they were amazing cars to drive, and also for the owners. They were beautifully made, nothing went wrong, ever... We just serviced them as per the service schedule and sent them back out on the road. Mazda claimed of them back in the day, more power and torque than the 3.0 JE V6, better fuel economy than the KF 2.0lt. Our owners certainly reported they were good on fuel. I actually loved the Eunos range, the little 30X hatch with the 1.8 V6 was great fun, and the 500 hardtop was a nice looking contemporary car for the time, very unique. Maybe you could do a video on the Japanese luxury era with the RISE of Lexus, Eunos, Acura and Infinity... 🤔
Dangermouse 4 ай бұрын
@NickShl He mentioned that, however the fact remains that part of the compression stroke is lost and power is reduced.
Tetraden 4 ай бұрын
Wait a second... Why do you look almost like Nicolaus Otto? O_O
Sean Lovi
Sean Lovi 4 ай бұрын
I can't believe am getting this education for free, it's almost illegal.
Makan Tahi
Makan Tahi 4 ай бұрын
then donate some money to be legal
jcork 4 ай бұрын
Please, don’t give the government any ideas.
Jj Fatts
Jj Fatts 4 ай бұрын
@jcork lol big bad "the government" better watch out! They'll get ya!
Litu the king
Litu the king 4 ай бұрын
Picki Panfil
Picki Panfil 4 ай бұрын
Selling education should be illegal...
Chief Denis
Chief Denis 4 ай бұрын
I dont think I've ever seen a bad video from this guy, been here almost/roughly 3 years, and this guy is the GOAT of mechanical KZhome school, no one explains things quite like him, and I've seen everything.
salleh sallehnewton
salleh sallehnewton 2 ай бұрын
The naked engine is a bad video
Chief Denis
Chief Denis 2 ай бұрын
@salleh sallehnewton eh, i beg to differ
Ishtiaque Hussain
Ishtiaque Hussain Ай бұрын
Thanks a lot, man! You are unbelievably good at explaining complex engineering topics. Please know that we really really appreciate your channel, your videos and everything that you do for us. Wish you all the best for the future!
Jim Osborn
Jim Osborn 4 ай бұрын
Excellent explanation. When I was learning I was taught efficiency is related to compression ratio. Later I discovered it is really a matter of expansion ratio. Atkinson/Miller cycles let you have an expansion ratio much larger than an Otto cycle.
Makan Tahi
Makan Tahi 4 ай бұрын
it can be monitored on 2 ways: 1. burning efficiency-higher pressure, higher efficiency, and 2. expansion efficiency: as nearer to atmospheric pressure/temperature as more efficient, so max eff will be if both are high: high pressure on the end of compression(start of combustion) and longest/expansion to the lowest temp/press on the end of expansion stroke
Mark O
Mark O 4 ай бұрын
Thank you! I finished the video, and for the life of me, 8 couldn't figure out why a supercharger wouldn't just cancel out the increased efficiency of a Miller cycle engine. Your comment finally cleared it up for me. 👍
Keith Yinger
Keith Yinger 4 ай бұрын
@Mark O that's what I couldn't wrap my head around either. Sure the Atkinson cycle is sucking in air and then expelling some of it, but if you add in a supercharger and crammed even more air in there, then wouldn't that higher pressure charge of air be harder to compress than the usual charge of air? I would think that extra force it takes to compress the tire pressure charge of air would cancel out the benefits of having a shorter compression stroke.
Mark O
Mark O 4 ай бұрын
@Keith Yinger I think the key is what Jim already said: it's not reduced compression that matters, it's increased expansion. The supercharger can raise the compression and the engine will still acheive improved efficiency, IF it has a longer expansion stroke.
Ferrum Ignis
Ferrum Ignis 4 ай бұрын
Both things are true, thermal efficiency is linked directly to compression ratio, but having an expansion ratio greater than the compression ratio also benefits efficiency.
Jasper Rodrigues
Jasper Rodrigues 4 ай бұрын
Goodness GRAVY! You are unbelievably good at explaining and illustrating things. I can only imagine how much time and work you put into honing your skills and knowledge. Thank you so much for posting your videos and sharing your knowledge with the rest of us. - Jasper
solconoclastic 4 ай бұрын
This probably won't mean much to anyone else but I remember finding a Japanese guys personal university webpage back in the mid 1990's. I'm not sure if he was a professor or a student but it was like an encyclopedia for Japanese car technology of the time. He had excellent technical explanations and diagrams for all kinds of things. You could tell the guy loved the topic and loved sharing how it worked. That was part of my introduction to the Internet and even though the site is long gone I still have fond memories. And this channel reminds me of that. It's the same kind of intelligent and passionate effort. The same kind of enthusiasm. And it's cool to see how the delivery format has evolved from basic text to full on edited videos with 3d animations. I really enjoy this channel and appreciate the work that goes into it.
driving 4 answers
driving 4 answers 4 ай бұрын
Believe me, it means a lot to me. Btw I have very fond memories of the early days of the internet too
Demef 3 ай бұрын
AND, he can pronounce all of the funny foreign names that none of us can!
Robert Gift
Robert Gift 3 ай бұрын
Why is the site gone?
Thinkle 3 ай бұрын
@Demef He is indeed doing it very well! It's not the ususal "wet" and "sloppy" American/english interpreatiation of letters, but pretty much to the point normal german or french, only "Yougene Langen" was a bit off, it should have been Oigen Langen, Like in oil and a G like in graphics.
vidaoTime 2 ай бұрын
have you tried finding it on the way back machine???
monti 4 ай бұрын
i needed this video so much, nobody explains engines better than you on youtube, many thanks :D
Duane Degn
Duane Degn 4 ай бұрын
I'm not a "motor head" myself but I love the videos on this channel.
Arthur Hakhverdian
Arthur Hakhverdian 3 ай бұрын
@Duane Degn I'm gonna close my eyes and picture the words coming out of Christoff Walz's mouth.
Ralph Warom
Ralph Warom 3 ай бұрын
This video reminds me to not take forbgranted what we have now. Its crazy how gold stuff I today compared to the early days of the ice
tarstarkusz 3 ай бұрын
What is in this video is wrong and right, but more wrong. You absolutely need compression to get high thermal efficiency. Compression is why diesel engines are so much more efficient than gasoline engines. Large expensive diesel engines powering things like container ships or desiel locomotives can reach 50% thermal efficiency Compression does not merely improve power, it improves efficiency.
Duane Degn
Duane Degn 3 ай бұрын
@tarstarkusz "You absolutely need compression to get high thermal efficiency." I thought the need for compression was stated in the video? The question is how this compression is achieved. The compression can be achieved using a supercharger rather than using the entire compression stroke. I don't know why compressing using a supercharger has advantages but I doubt Mazda would add this complication without having a good reason.
C.A.R.S. (Cars And Relevant Specs)
C.A.R.S. (Cars And Relevant Specs) 4 ай бұрын
Another fantastic video! I especially appreciate how you differentiate between the Atkinson and Miller cycles and how you explain that in modern engines they are essentially the same in concept and practice. Thanks again! 😃
Laurent BRUNEEL 3 ай бұрын
Man, as always you do an excellent job at explaining mechanical concepts in an accessible way. Thanks so much ! I always wondered what was the key differences between Atkinson and Miller cycle. By the way, the Eiffel Tower still did not exist at the time Otto patented his 4 stroke engine 😅
Loveitdownunder 47
Loveitdownunder 47 4 ай бұрын
Have done 50 years in the motor trade and now retired, as always this is the best description and graphics by far. Thanks.
Nagy Sandor
Nagy Sandor 4 ай бұрын
ozzie ozzie ozzie
Loveitdownunder 47
Loveitdownunder 47 3 ай бұрын
@Nagy Sandor 👍🙃
Nagy Sandor
Nagy Sandor 3 ай бұрын
@Loveitdownunder 47 :))))
pontifier 3 ай бұрын
In high school I independently came up with the miller valve timing idea for increasing efficiency of four stroke engines. My reasoning was not to reduce the energy of the compression cycle, but realizing that a combusted fuel takes up much more space than it did before, the power stroke should be longer to allow the piston to reach atmospheric pressure before the exhaust stroke starts.
That1GuyOnPoint 4 ай бұрын
Another great video. As a mechanical engineering student you've taught me way more than any class ever could!
d k
d k 3 ай бұрын
You really need to pay attention in thermodynamics as this guy got it all wrong.
Eli 3 ай бұрын
@d k What did he get wrong? In my thermodynamics class we analyzed the Otto and Diesel cycles within a control volume and neglected energy loss, energy in and out, and mass in and mass out . We solely focused on the changes in temperature and pressure within the control volumes to keep things simple. The video doesn’t go into depth about the chemistry and thermodynamics but his approach is realistic and applicable. I didn’t notice anything wrong about the information in this video but I could have missed something. 🤷🏽‍♂️
d k
d k 3 ай бұрын
@Eli In my thermodynamics classes, we learned how to analyze the Carnot, Otto, Diesel, Stirling, Ericsson, Atkinson, Miller, Brayton, Rankin, 2 cycle internal combustion engines, along with the effects of turbo and super charging (with and without intercooling), economizers, super heat, reheating, and much more. He got the linkages correct. But the linkages aren't why an engine makes power. They make power by extracting heat from a gas due to the expansion of those gasses. As we know efficiency of an otto cycle is proportional to the compression ratio of the engine, the compression stroke doesn't rob power from the engine. In the case of the Atkinson and Miller cycles the efficiency closer to the expansion ratio of the engine. The reason these cycles were developed was to allow greater expansion ratios while still using externally mixed low octane fuels to control knocking and preignition which is limited by the compression ratio. The 'super charger' in the Miller cycle wasn't replaced by an electric motor. There were naturally aspirated Miller engines in constant speed use before Toyota and Mazda. Which is basically how they are used in hybrids with generators and CV transmissions. The reason for the electric motor is to allow for a lower power, lighter, smaller displacement, high efficacy engine that runs at a constant speed and constant power most of the time. An auto only needs full power for very short periods of the drive cycle such as starting from a stop, climbing steep hills. I could go on.
Magnus Gustavsson
Magnus Gustavsson 2 ай бұрын
@d k I agree with you point on thermodynamics, It is the longer expansion cycle that gives a more complete combustion. About Toyotas hybrids, I think he meant that the supercharging is replaced by the electric drive at low rpms of the engine.Basically, the engine i an hybrid can work on a single rpm so there is no need for a responsive and low torque engine there.
d k
d k 2 ай бұрын
It has nothing to do with how complete the combustion is. In our regular gas engines we aren't allowing unburned fuel to be exhausted. We just aren't expanding the gas after heating it as much.
Jethro Stuff
Jethro Stuff 4 ай бұрын
I’ve always thought of this more as increasing the power stroke length to extract more usable energy, rather than decreasing the compression stroke. It’s really the same thing, but I believe it better expresses the intent of increasing efficiency. Thanks for the video! Good stuff.
Crézy Chameau
Crézy Chameau 4 ай бұрын
I also like this way of explaining the concept better :) It is litteraly the concept behind 5 strokes engines
kilura1 4 ай бұрын
Yeah, this is quite important. See, If you have less mass of air + fuel mixture in the end of compression stroke, the pressure and temperature of gasses will be smaller in the end of combustion stroke (compared to OTTO cycle). This can be also achieved by throttling air intake during suction stroke (basically, this is what happens when you release gas pedal, gasses outlet temperature drops down). But this will strongly increase intake manifold resistance => efficiency will be less. Also Mazda's Skyactiv engines are designed to have very big Compression ratio. This allows you to maintain Pc (compression pressure) same as in OTTO engine. (In general, increasing Compression and Combustion pressure leads to increasing of efficiency). Marine Diesel Engines now have gigantic stroke of up to 3.5 meters(!). In order to expand gasses as much as possible thus utilizing as much of energy as possible.
Allan Allansson
Allan Allansson 4 ай бұрын
Agree! This increase power extraction even overcomes some of the thermodynamically unavoidable losses due to lower compression. Part of the efficiency of diesel engines is their high compression ratio and ethanol mix in in gasoline makes for higher efficiency due to higher octane value which allows higher compression ratio without knock.
Chris Smith
Chris Smith 4 ай бұрын
Pumping losses are the problem with petrol engines, diesel does not suffer from them.
Ferrum Ignis
Ferrum Ignis 4 ай бұрын
@Chris Smith Even diesel engines suffer pumping losses,they are just lower because they are not usually throttled (though some diesel engines are). The additional pumping losses on a petrol engine occur when the engine is throttled upstream of the intake valves, so the piston is expending energy working against the partial vacuum in the intake manifold/plenum. This can be eliminated by not throttling in this way, instead using adjustable valve duration like the BMW Valvetronic system or Fiats Multiair.
Brent Lanyon
Brent Lanyon 3 ай бұрын
Well done. I've googled Atkinson cycle a couple times because I know that is used in the Prius. This very clearly states the difference from Otto cycle (less compression stroke), the resulting efficiency gains, and the performance trade offs.
Kim Keam
Kim Keam 2 ай бұрын
I was not fully aware of the differences between the type of cycle but really appreciate the information you have provided for us. Thanks!
Jeff Haluska
Jeff Haluska 4 ай бұрын
I have been enjoying the history and engineering lessons you provide on engines. It really helps me understand and appreciate them more.
Ben Hallam
Ben Hallam 4 ай бұрын
Great video as always. I love the way you present such dry subjects in ways that make them genuinely interesting and entertaining. Keep it up.
M C 4 ай бұрын
Good video, I enjoy when you look at the different types of one thing and explain the similarities, differences, and history! I thought the Miller Cycle Mazda Millenia S was so cool back in the day (as a comfy sedan goes). A video like this on the history and variety of variable valve timing systems would be neat. Or even maybe before that, just valvetrains in general?? I feel like I know most of this stuff but you always manage to slip in a few new bits of info.!!
B B 4 ай бұрын
Fun fact: Some of Cat's ACERT diesel engines (BXS and MXS for example) also used a miller cycle. Boost close to 60psi was provided by series turbos. I think there was a variant of Cummins' big cam engines using the miller cycle too.
C W 3 ай бұрын
ACERT is Miller cycle. Helped meet EPA07 by reducing NOx production in cylinder. Pretty cool stuff. Basically reverse Jake brakes
Brad Ferguson
Brad Ferguson 3 ай бұрын
You're right. And it's switchable. There's a brake-like device on the intake rocker called an IVA that can hold it open longer. It can be turned on as needed.
GuidoK 28 күн бұрын
​@Brad Ferguson If it didn't have that it probably would be impossible to start.
Lior M
Lior M 2 ай бұрын
Guys totally love watching your reviews. Bought a car (unrevoewed) a few months back, still watching with joy, but this was so super brilliant and I am so happy to see it. Loved it all, but Jim's bit had me in stitches!
steve witzke
steve witzke 2 ай бұрын
Wow. I’m seriously considering buying a hybrid minivan. My uncle was a member of the Ram Chargers racing team in the 60’s. He introduced me to the Atkinson engine/electric motor combo but this explains it best and I love the history lesson too! Now because I understand the concept differences, I’m going to buy a hybrid… like his new hybrid Pacifica which he loves.
Dmitry G
Dmitry G 4 ай бұрын
Would be good to hear more about the sky active technology from this channel, your explanations are unmatched
Raj55 4 ай бұрын
Wow, once again thanks. You are raising our knowledge and understanding of IC engines almost vertically. We want more!
Paul Thomas
Paul Thomas 4 ай бұрын
Thank you for the BEST comparative explanation of these 3 piston engine cycle types! Very clear & precise!
olavl 4 ай бұрын
Great video as always. Personally I'm not much of a car person and I drive just a cheap old boring car, which serves my needs. But I love learning about technology and engineering in general and this explanation was just fantastic.
velvetsmack 3 ай бұрын
Great explanation and video. Learned quite a lot. I actually owned a Mazda Millenia with the miller. I truly miss it. What's interesting about this tech is that we're now looking at the new age of electric, which ultimately means (or will mean) times almost up on this piece of engineering. Hydrogen may save it for a while, but I see a driven world with less engineering complexity - which would maybe lead to its ultimate demise.
Matthew Beaver
Matthew Beaver 3 ай бұрын
I really appreciate your videos. I've always had a general understanding as to how ICE works. Gotta have air spark and fuel. These videos go so indepth of the how and why. I feel like I'm getting the automotive education I missed out on by not spending my high school elective classes at MOvTI
Erik Kraemer
Erik Kraemer 4 ай бұрын
Amazing video. The way you go through history is super entertaining, at least for an mechanical engineer. About the names of the cycles, what I understood is that Atkinson is the name of the thermodynamic cycle, and there're several practical applications such as the Miller engine.
EvilJ069 3 ай бұрын
Also of note: The KL series of engines had different variants, the 170HP (164) you list is the KLDE ASPEC version whereas the JESPEC KLZE put out 199HP N/A
kevin pulver
kevin pulver 4 ай бұрын
You taught me something! I have castings for a model Atkinson Cycle engine. But I didn't realize that the compression and power stroke lengths differed. I know some guys in Nebraska who have working examples of Otto's "Schumm" engine referenced in your video. For those who want to read more about the history of engines, "Internal Fire" by Clessie Cummins has a lot to say.
Francois Tombe
Francois Tombe 3 ай бұрын
Clessie was the founder of Cummins ( and has his own autobiography ( pun unintentional)). His son wrote Internal Fire. He used the name Lyle Cummins, but as C Lyle Cummins so I guess he is Clessie junior.
Jake Martin
Jake Martin 4 ай бұрын
This is amazing ive always believed that knowing how something has evolved over time helps you understand the current technologies and even helps is repairs of those technologies as well love this channel 👏👏👍
Nukey Nunu
Nukey Nunu 4 ай бұрын
You can also supercharge Toyota's Atkinsion engines. It was totally interesting, when I saw a supercharged CT200h on a car show. This thing made just above 300hp, and was a menace on the track.
Eloise Harbeson
Eloise Harbeson 3 ай бұрын
There was a privateer that developed a KTM single 4-stroke top end on a dual crank bottom bottom end. One of the features of this engine was faster compression stroke (for less losses) and a slower power stroke (for increased torque). I was surprised that the concept was not carried further.
BrianDMS 4 ай бұрын
Awesome stuff, never knew there's more than a single type of modern gas engine cycles, great history lesson too!
Robert Poudrette
Robert Poudrette 3 ай бұрын
Beautifully explained! I knew Mazda had a special engine in their Millenia with the Miller cycle and this video clearly explains why Mazda experimented it years ago. Very cool! Thanks!
Zaid Kidwai
Zaid Kidwai 4 ай бұрын
Fantastic work my man. Love your videos, explained clearly and concisely.
Logan P E
Logan P E 4 ай бұрын
Very, very interesting video! I was retiring as a mechanic at the time Mazda announced it's SkyActive engine, I heard about it but didn't pursue any research, I had no idea it was based on the Miller cycle! Thank you, great information as always!
Jay Braaten
Jay Braaten 3 ай бұрын
I really appreciate your channel. You have helped me in so many aspects in life. Not only in engines and physics but in the willing to learn and aspire to gain every bit of knowledge I can. Thank you🙏🏼
driving 4 answers
driving 4 answers 3 ай бұрын
I'm overjoyed to hear that. Thank you.
KO 3 ай бұрын
I have known of these engines for a long time but now I actually understand the difference between them! Thanks.
hoganfan924 19 күн бұрын
Good video. Ralph Miller’s original idea was to close the intake valve well before BDC to increase efficiency. He wrote about this (as I recall) in a 1948 ASME paper. I read his paper 25 years ago while working on VVL/VVT concepts for Chrysler. This works very well for low load efficiency (up to about 8% improvement), due to virtual elimination of the pumping loop by running unthrottled, and is what BMW Valvetronic and Fiat does Multi-air to run “unthrottled.” A guy at GM named Don Stivender did research on extremely low lift cams in the 60’s, and another GM guy named Tuttle made very short duration cams (with more normal lifts) in the early ‘80’s, testing Miller’s original concept. Tuttle also ran very long duration cams to control load (testing the later miller approach) Stivender claimed a 5% improvement in efficiency, and Tuttle around 8%. Stivender called his very low lift the STIVE cycle (Sonic Throttling Intake Valve Engine). Very clever! I built some very short duration cams with moderately low lifts to verify the blended “Stivender & Tuttle/Miller” with the very early intake valve closing concept in our 1.6l “Tritec” engine in 1999/2000 and verified the concept could deliver about 6-8% lower BSFC unthrottled. Most folks (even engine guys) didn’t understand how this works, but the evidence is right in the P-V diagram, and the virtual elimination of the pumping loop. Here’s are links to Tuttle’s 1980 & ‘82 SAE papers(I couldn’t find Miller’s): Here’s Stivender’s paper:
Peter Clark
Peter Clark 3 ай бұрын
I would expect the Atkinson cycle (with linkages) to be very clean burning, approaching complete combustion, and as a bonus higher torque or more torque for a given energy source. Ideal for a Hybrid generator if not connected to the drive train. Very interesting video, cheers.
Rice Burner
Rice Burner 4 ай бұрын
Brings back memories in my HS auto shop class 50yrs ago. We called 4 cycles, intake, compression, POWER, exhaust. Great video! I own a gen 4 Prius, & for my love of cars, I can never learn too much, ESPECIALLY Atkinson engines. Thank u! 👍🇺🇸
Alexandre Negrão
Alexandre Negrão 4 ай бұрын
I'm always learning something new watching your videos...thank you! Would you please make a video about Toyota's M20A engines? Here in Brazil Toyota sells the FKB version, wich is called"flex" because it can run on petrol or ethanol (from sugar cane).
The Man from FUNCLE
The Man from FUNCLE 23 күн бұрын
I can't believe how mesmerizing these technical videos are. D4A, you are a master storyteller, even though you refer to the strokes as ICIE instead of SSBB
Erwin Zeeland
Erwin Zeeland 3 ай бұрын
Very, very well explained! But what about the effect when the crankshaft is positioned slightly out of the centre of the cilinders? Because that also has effect on the percentage of rotation needed for up- and downstroke.
Pietro 4 ай бұрын
I study mechanical engineering in Italy, just learned that in 8 cycle the intake valve closes a bit after bdc (you said before) in order to have a good volumetric efficiency (the inertia of air is the reason , with a perfect fluid the best closing would be at bdc). Obviously still much before than miller cycle.
Fábio Pereira
Fábio Pereira 3 ай бұрын
The goal is not to reduce the amount of energy wasted during compression, but to increase the expansion stroke. Just look at a PV diagram.
Jozsef Izsak
Jozsef Izsak 4 ай бұрын
Thank you so much! This was interesting and informative but also uplifting, due to how wonderfully well you explain things.
George s
George s 4 ай бұрын
Very well presented. I especially enjoyed the historical aspects of engine designs. Would you please, explain how these engines are lubricated? What is happening to the oil in the engine?
Abba Rasheed
Abba Rasheed 4 ай бұрын
Also to add to your plea, how the engines are cooled too with liquid cooling
SAMRODIAN 4 ай бұрын
Fascinating video. Thank you that was so informative and I had no idea about Mr Millers engine design, and the VVT was the reason behind its introduction in so many manufacturers engines. I myself had a Toyota 1300 cc VVT engine in my Yaris from 2001.
Daniel Wainscott
Daniel Wainscott 3 ай бұрын
I love your videos, truly fantastic explanation, visuals, script, topics, up-to date subjects!! Quick question about this, has anyone ever made a Miller engine with Turbocharger? It surely would not solve the low RPM lack of power/torque issue, but I'm very curious how numbers would change compared to a Supercharger. If I could ask for a subject for a video, it would be a retrofit system on a currently available naturally aspirated or turbocharged engine with an additional compressed air system for additional power and low end torque - I'm curious what you think of the theory behind it, and if anyone made it to the mass market already. I am aware from the Polytechnics University of Budapest that 'someone' was introducing a similar idea for turbocharged diesel buses and trucks for better takeoff capabilities. Anyways, vielen Dank!
tommywallbanger 4 ай бұрын
Love your videos they are incredibly informative but explained in a way that is easy to understand.
T Schreiner
T Schreiner 3 ай бұрын
This is one of the best series on You Tube. Wonderfully presented and understandable. Thank you.
Kerry Lewis
Kerry Lewis 3 ай бұрын
I may still be seated, but I'm giving your explanation a standing ovation. Fantastic video
Gugle Gugle
Gugle Gugle 3 ай бұрын
Bardzo dziękuję👋 W zaledwie 20 minut pozyskałem sporo wiedzy świetnie zobrazowanej i bardzo logicznie przedstawionej 👌👍
David Short
David Short 3 ай бұрын
Thank you for such an informative article. Your explanation ot the Miller Cycle was far superior and easier to understand than that of a Mazda Dealership Service Manager gave to me in the 90s. Cheers.
Tom Schmidt
Tom Schmidt 4 ай бұрын
Great explanation. I had heard of the Atkinson cycle used by Toyota in their hybrid cars but I have never heard of the Miller cycle. Thanks for the education.
Eric Salmazo
Eric Salmazo 4 ай бұрын
Unbelievably good content. Thank you for your work.
xXVintersorgXx 3 ай бұрын
My dad had one of those millennium's. It was a great car until the super charger self destructed. The major problem with it was actually that it required high octane gasoline
Magnus Gustavsson
Magnus Gustavsson 2 ай бұрын
Would be perfect then on E85!
xXVintersorgXx 2 ай бұрын
@Magnus Gustavsson I think it needed 91 octane according to the manual
Thomas Gires
Thomas Gires 4 ай бұрын
I guess Toyota didn't want people to think "It's Miller time!" about their engines :D Seriosuly though, thanks again, I knew the basic conceptual differences between these engine types, but you have brought me a new level of understanding :)
Greg Roles
Greg Roles 3 ай бұрын
Considering buying a Skyactiv CX-5 turbo for the missus, and had my head around Miller cycle a bit, but wow, this has to be the best and most visually perfect description I've yet seen. Kudos!!
Patryk C
Patryk C 3 ай бұрын
Great video, explaining all the difference between different cycles in modern engines. Have Toyota hybrid car and absolutely love it. People think that hybrid is slow and underpowered, but have proved few drivers that is not the case when leaving them behind when light goes green at the junction.
datathunderstorm 3 ай бұрын
Hahaha!! I do that everyday during my commute, with my 14 year old Prius Tspirit Hybrid. 145k miles on the clock and this car just GOES when you need it to. All glory to the Atkinson Cycle engine incorporated into the equally legendary Hybrid Synergy Drive. Managed 69.4 mpg out of a 45 litre tank of fuel last summer, also travelling 653 miles out of the same tank of fuel - amazing performance from a vintage 2nd generation Prius - I wasn’t babying it either - this happened during the unprecedented heatwave in London last summer. 😊
poopy pants
poopy pants 3 ай бұрын
It's cause the engine doesn't drive the wheels directly, so engine power doesn't have a direct affect on power. Your battery health and capabilities will affect the speed much more. Hence why the newer ones are much quicker than the older ones.
Esdras Castillo
Esdras Castillo 4 ай бұрын
Thank you for this video. I'm studying for the ASE exam and my book goes over this topic briefly. Not only you go over the history but you also show examples
fuzzycuffs 3 ай бұрын
This was so amazingly informative. I linked so many previously known concepts and practices about motors together after this video.
Formbi 4 ай бұрын
the Atkinson&Miller cycle also extracts more energy from the combustion (that additional energy is what is sometimes used for turbochargers after all)
Pirat 3 ай бұрын
I needed this explanation really badly ever since I was at a Lexus showroom and they boasted having 'Atkinson cycle' engines, but none of the salespeople could explain how it works. It was driving me nuts. Google only had general explanations that always felt incomplete.
GuidoK 28 күн бұрын
Salespersons usually aren't techies. A good salesperson would get a mechanic from the shop to explain that for him.
Pirat 28 күн бұрын
@GuidoK I don't care. If someones selling me something they don't understand - I'm not buying it. If they can't even explain things that are on the sticker then how am I supposed to believe anything they say?
Merlin Glennon
Merlin Glennon 2 ай бұрын
Obviously very knowledgeable person, thanks for your time. Was wondering if you could do a video on 60/40 type transfer cases with center differential. Changing torque and not speed though gears, is a hard concept. Thanks
Karl Plasser
Karl Plasser 4 ай бұрын
Thank you very much! I finally understand how my Ford Galaxy Hybrid can have an Attkinson motor without having funny rods. Your lesson was extremly revealing.
David Lobaugh
David Lobaugh 4 ай бұрын
Solid work, good job. Another caveat of the Otto cycle being better for non-stationary engines is that better power density means less weight which is obviously more efficient. So the small "inefficient" engine is ...more efficient. And packaging, cost, complexity, etc as the man said.
Appletank8 3 ай бұрын
Well, efficient for packaging, not necessarily efficient thermally. Power plants can be very efficient because they don't need to fit inside an engine bay, for example.
rkc62 3 ай бұрын
This is amazing - thanks for posting! The explanation graphics are excellent as always, but the Otto history graphics are exceptionally entertaining.
Mark Edwards
Mark Edwards Ай бұрын
That’s the best and simplest explanation of the differences between engine types that I’ve ever seen. Well done. What is really amazing though is that all of these are going to be made useless with the even more rapid developments in battery and electric tech. I loved my V8s and manual transmissions but am addicted to the responsiveness and power of my EV. No more fuel burning.
Rene Neron
Rene Neron 4 ай бұрын
Great video. Not all Toyota hybrids use the Atkinson cycle engine in their hybrids; the 3MZ hybrid engine does not. Further, Toyota will often increase the base compression ratio on an engine used in the Atkinson cycle model so that the effective compression ratio is similar to the Otto cycle version (an example being the hybrid 2AR-FXE versus the standard 2AR-FE). The camshaft profiles and valve timing are different as well. With proper engine management, the 2AR-FXE can be operated as an Otto cycle engine to gain power with a loss of efficiency with higher octane fuel. There is still a loss of power with the Atkinson cycle compensated for by the electric motor, but improved efficiency. Detonation (and octane) limits the practical compression ratio of any gasoline ICE engine.
tripplefives 4 ай бұрын
Toyota uses miller but calls it Atkinson.
poopy pants
poopy pants 3 ай бұрын
It should also be noted that these engines are not actually driving the wheels in the hybrids.
Miwna 4 ай бұрын
Brilliant video as always! You're really good at explaining these things. Where would Infiniti's variable compression engine fit into all this? They they released it a couple of years ago. It had some black magic trick with the crankshaft to tilt it, thus altering stroke and compression. I guess that's more of an Atkinson-style.
Videum Fantasticum
Videum Fantasticum 3 ай бұрын
great clip, you presented a lot of concepts I wasn't aware of. Biggest surprise is that hidden behind marketing mumbojumbo these basic concepts (Atkinson/Miller) have been taken into production. Thank you for compiling all this into a well produced video.
Michael Pelletier
Michael Pelletier 4 ай бұрын
Man, you have a way to put things clearly and interestingly at the same time! I did know some of this already, but know I've learned what I didn't. And what I was lacking turned out to be the bigger, more interesting part And I love the way you speak. Thank you very much for your work.
The East Man
The East Man 25 күн бұрын
Great video, excellent explanations, funny illustrations and clear thinking; a very efficient information engine. Thank you. 🙏🏼
Sandor D
Sandor D 3 ай бұрын
It couldn't have been more clearly explained! Thanks!! 👍
Arieh Davidoff
Arieh Davidoff 4 ай бұрын
This was excellent! Very clear chronology and explanation.
Fell’s Point
Fell’s Point 4 ай бұрын
Wow, very well done. You covered a lot of technical ground in a clear and concise manner.
Jylpah 3 ай бұрын
It was great to learn this before gasoline cars are history. Great video. The marvels of engineering are always amazing 😊
driving 4 answers
driving 4 answers 3 ай бұрын
The marvels of fake news are even more amazing
brianorca 3 ай бұрын
Another way to look at the efficiency gain in Atkinson/Miller engines is, yes the reduced compression stroke takes less energy, but also the relatively extended power stroke doesn't lose energy to the exhaust. Even though the cylinder has the same volume at the end of the Otto power stroke, the ignition has substantially increased the pressure. So by extending the power stroke, you can extract energy that would otherwise be lost when the exhaust valve opened.
Paul Victor
Paul Victor 3 ай бұрын
Great info as always thanks. I love your videos. What is the difference between a car engine and marine outboard engine?
Душан Стефановић
Душан Стефановић 4 ай бұрын
Svaka čast, mačak. Pratim te već neko vreme i uvek je zadovoljstvo. Samo nastavi! 👌
TunebyAOT Philippines
TunebyAOT Philippines 4 ай бұрын
Learning at its best! 👌🏻
Priidik Möls
Priidik Möls 3 ай бұрын
Great history lesson and concise explanation. Thanks!
Akshay Muley
Akshay Muley 2 ай бұрын
well 3 years back, my masters thesis was based on toyota prius powertrain and I enjoyed watching your video some memories refreshed 😃 Toyota actually made some electronic adjustments using VVT in traditional otto cycle engine which gave them good success in reviving Atkinson cycle…very smart people behind it. ever wondered how a turbocharged prius will perform? 😉
Asker 3 ай бұрын
Хорошая лекция! Схемы очень хорошо нарисованы!
KK89 3 ай бұрын
Yet again an amazing video! I have a Toyota Auris hybrid. Very interesting to see the history of the motor! Thank you!
Marjan 4 ай бұрын
Excellent explanation as always. I'm looking forward for another video that will explain how VVT fully works. In this video is that just touched a bit. Thank you.
Nick Rider
Nick Rider 4 ай бұрын
Very well described sir ! and extremely fascinating 👍
Mike Drop
Mike Drop 3 ай бұрын
Thanks for this, I've worked on cars my whole life and always wondered about these oddities. Edit: so basically Freevalve allows Otto style engines to become Atkinson/Miller style engines on the highway to reduce fuel consumption. Edit again: Oh you covered that too. Lol
Ali Alshekarchee
Ali Alshekarchee 3 ай бұрын
This is exactly why KZhome should exist, a great content as usual, your videos never disappoint to gain my full respect! Cheers
Bernie Schattka
Bernie Schattka 4 ай бұрын
Another very education video, thanks! FYI, I believe the Skyactiv X engine was preceded by the DiesOtto engine introduced by Mercedes-Benz. GM also researched HCCI engines, but the name of their engine/technology escapes me.
ZIGgassedUP 4 ай бұрын
I once wanted to put a Miller mazda supercharger on a 2.5 Mazda NA engine 'cos the Miller pumps upto 20psi of boost...Real hard to find them now days...Love the show mate.👍
Jack Richards
Jack Richards 3 ай бұрын
This is the most revealing story of engine types I never heard before. Thanks Mr.
Swerving Lemon
Swerving Lemon 4 ай бұрын
You're awesome. I was wondering about this last week. Your animations make the concepts very clear.
Mike Who
Mike Who 3 ай бұрын
Excellent - a clear and concise explanation of the differences - thanks
Tim Winters
Tim Winters 4 ай бұрын
Yet another example of excellent research and presentation from our favorite engine tech guy explains fully this oft misunderstood subject.
Tom Lahaye
Tom Lahaye 4 ай бұрын
Excellent explanation! Essentially the development of the ICE followed the same route as that of the steam engine. First steam engines as developed by Thomas Newcomen in 1712 were atmospheric, the engine would suck steam at atmospheric pressure into the cylinder at the downward stroke of the piston, the valve would close and the steam allowed to condense as the cylinder wall was cooled by water. The condensation of the steam would create an under pressure wich sucked the piston back upwards. These engines also had poor efficiency and low power output, 5hp for an engine that filled a building, they were used to drive pumps at coal pits. Then someone got the idea of using steam created in a boiler under higher than atmospheric pressure, and using the expansion of the steam trying to equalize it's pressure to atmospheric pressure, and not to condense. Power output and efficiency raised dramatically, steam engine became small enough to power vehicles on rails and road. So a very similar story thus, and I think the development was a continuation of the development made in steam technology, and the idea after the ICE at that time was to drop the steam generating boiler with its thermal losses and space requirements.
Хорватская тачка ▶️ Тесла #shorts
This is Хорошо
Рет қаралды 3,3 МЛН
PLANETARY GEARS why they are pretty cool
Logic Lab
Рет қаралды 45 М.
DIY wheel cribs (wood jack stands)
Рет қаралды 30 М.
Learn about every Engine Layout in just one video | V-W-X-U-H Engines
The Engineers Post
Рет қаралды 385 М.
How a engine works
Рет қаралды 10 М.
AUDI TT 8S impossible parking - Beam NG DRIVE
Рет қаралды 47 МЛН
Миша и Женя снова вместе! Как живут и на чем ездят звёзды?
Автосалон Синдиката
Рет қаралды 1,4 МЛН
Сколько стоит Турботаз. #жигули #ваз2107 #турботаз
Авто Док, Шатура
Рет қаралды 413 М.
Eksperimen!! Modifikasi Sepeda Roda 4 Bertingkat
aseli bmx
Рет қаралды 1,8 МЛН
Рет қаралды 1,5 МЛН
Хитрая поломка редкого Saab 9-5 Aero. Такого Вы еще не встречали )