How GM's Variable Compression Engine Works - Patent Review
Motor
GM’s Patented Variable Compression Engine - How It Works
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Internal combustion engines have a flaw. When the piston reaches the bottom of the power stroke in a traditional four-stroke engine, there is still a high pressure contained within the cylinder. This pressure is released when the exhaust valve opens, ultimately wasting energy. One potential solution is an Atkinson cycle engine, which increases the expansion ratio, relative to the compression ratio, resulting in greater efficiency.
The problem with the Atkinson cycle is that because it reduces the intake stroke length, less air and fuel are drawn into the cylinder, and overall less power is created. In this video, we’ll explore GM’s solution to this problem, which is to create a variable compression ratio Atkinson cycle engine. Check out the video to learn all about GM’s patent!
Patent Source:
patents.google.com/patent/US20170284291A1/en
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Kommentarer
Hope everyone's having an excellent day! What do you all think about this style engine versus Nissan's VC Turbo? Thanks for watching and thank to Skillshare for sponsoring! First 500 to sign up get 2 free months! skl.sh/engineeringexplained2
787brx8
År siden
@Marc Asposito I have helped out Japan A little more than the American automakers for quite A while now. I did the initial design work for many vehicles since the seventies. (child prodigy) Over time people have begun to think Japanese designs are superior but the reality is, they are American designs made in Japan. A few of my similarly named works... VTEC, Vortec, Voltec, Duratec, Ecotec and Ecoboost Of course there were many more designs that I have created. Some were for the military. On my page I have various videos with A few examples of different projects people can check out if they want to. One is for an anti-knock device that should make compression ignition gasoline engines fairly easy to do. On A regular engine it allows me to advance the ignition timing to the maximum factory setting. Which is something you cannot do, even with race fuel! Pause on the distributor part, if you wish?
Joel Leehy
År siden
Nissan VC-Turbo is a whole world better
Marc Asposito
År siden
Working as an Engineer I have developed over 100 1st Gen small block Chevrolet engines, and in technical inside sales at a U.S. engine remanufacturer taking calls from all over the country hearing from automotive enthusiasts, mechanics and the general car consumer gave me real insite of what engines are failing on large numbers call after call after call some people even crying in disbelief at the financial crisis a failed engine put them in. Mechanics telling me they see three of these a day, every day. Several engines with less than 100k miles. So what do I think....deveopment of anything and the long term reliability, that we who own and work on 1990-2010 pre-direct injected Japanese developed automobile engines, depends on several factors and most importantly the background of the Engineers the engine builders hire. GM can build some of the best pushrod engines, but they need the best seasoned Engineers from Japan if they are going to make long term reliable engines the likes of Honda, Nissan and Toyota, who are also not without their own errors in the last 20 years. Personally as an automotive enthusiast and not a car consumer, I would wait years to verify reliable technology. The shift I am seeing is not long term reliability, but rather a disposable mentality just past the warranty period. My advice stay away until it's proven, and stick with what is proven reliable. It's your money not the ignorant person who tells you what you should buy.
Oblithian
År siden
Nissan's is better.
eli oliver
År siden
I've heard the skyactive x feels pretty powerful for the amount of fuel it uses
Nissan VC turbo ?
You continue to blow my mind all the time!
So the blue linkage is free moving at both ends and the red “linkage” crankshaft is of course only free moving on one right? But then GM went and made the position of the STILL free moving linkage change? Which is like taking a normal variable compression engine and adding an extra degree of free movement? Also what about having the blue part be a second crank type shaft with a gear ratio to the red one, or just different “lift” than it, would either of those options work and do anything or would the ratio thing just make it change once per cycle?
I see a lot of points of failure... I can see this in a low power, relatively unstressed, all about economy engine. But in a high power application? Bits & pieces everywhere.
So is this a 4 cycle engine or 2 cycle or something else
Saab developed this in beginning of millenium. That time Saab was owned by GM and was testbed for new ideas.
Hey Jason, have you done any videos on the koenigsegg free valve system Wouldn’t you be able to get rid of all this complicated mechanical issues by simply running the free valve systems. ? Or am I missing some advantage here?
Imagine thinking you blew it up so you do a compression test lol
Let's assume the crankshaft is rotating at steady RPM. The piston movement is almost 2 times during exhaust stroke than any other stroke in this design thus it may have some issues related to excessive wear due to piston being thrown around at various intensities.
It would be really helpful to see a physical example of the Traditional Atkinson Cycle. Also maybe you should clarify that you a talking about an Otto cycle so people don't think you're saying auto (like automotive) cycle.
similar to the nissan design in a way.
Well done time, but sometimes,...an animation is needed, this is one of those times.
Nissan VC-Turbo is way better
Insane emission limits leading to insane mechanical engineering. The end of the story is always the same: the ordinary person will spend A LOT on maintenance or even loosing all the value by junking the car after a couple of years. There was a time that a car was somthing popular and accessible by everyone. From now on, it seams to be the reverse.
In operation, would there be an audible difference (with the difference in C.R.) like in old school VTEC's application?
GM and Nissan, names not really associated with reliability making a funky system with more moving parts and more complexity... what a time to be alive...
Not sure with whom I’m more impressed with , the GM engineers or you for explaining this so we can understand 👍 lol
10:40 area....wouldn't adding forced induction increase the compression in that cylinder though? i dont understand why high compression would cause knock either.
The kinematics of this system looks awfull complicated compared to a normal piston rod and crankshaft.
✌
Waiting to see video of one of these grande on dyno...
Yay, more moving parts! For reliability of course...
I couldn’t even draw that, much less explain it.
America such an awesome country and highest tech of everything. But, why can't American cars have better tech than other makers?
Wankel engineer: there are too many parts in 4 stroke... GM: Hold my beer
Comparision with Nissan infiniti VGT
Nice, but you don't need this. For normal passenger car you use as high compression ratio as possible, and for sporty car you lower it to get more boost, sporty car doesn't need to be eco-friendly and they're low volume products anyway.
Variable compression Can work in v engines?
2:34 feeling when you say " Engineers are very clever"🤣
Great simplified description. I think I learned something. Keep up the great videos.
Vtec for camshafts
This is the first time I watched one of your videos from beginning to end. I usually don't because i don't like watching you just write stuff on a white board. I actually enjoyed this video and I'm going to watch a few more now 🙂
recall central
since the intake valve is going to stay open as the Pistons coming up I'm assuming that they're going to implement some type of supercharger to turbo turbocharger similar to of a Mazda Miller cycle engine that way that the air will be forced in as the Pistons coming up.
If you got longest stroke journey for each all 4 strokes, why don't GM retard the valve timing?
This is great!
how well would this work for a range extender? what kind of engine would be best for a serial phev? or whatver you call a volt style optionally serial phev?
If this was a toyota people will clap "fantastic job toyota" but when gm makes that "it will bReAK ". WHAT ABOUT VTEC DO THEY BREAK NOOOOO. SO ADDING LITTLE ELECTRIC MOTOR TO MOVE CRANKSHAFT IS NOT A PROBLEM.
For the right application it has a place. GM’s Northstar seems to come to mind on GM’s specialty Engine Evolutions.
Cool concept but I can't get my head around the fact that the drag from all the extra moving parts would offset some of the efficiency gains? Those complaining about reliability should really read up on cam in block and flathead engines. There were naysayers every time a major innovation like this came about. Reality is we now have overhead cam, direct fuel injection, hydraulic automatic transmissions, etc that last hundreds of thousands of miles without need for major overhaul
Haven't you wondered why crankshafts have a certain size? Haven't you wondered why they don't make the bearing surfaces of crankshafts thinner? Have you looked at the reliability of engines where they did do that? Do you think this many links is gonna last? And now take into consideration that the conrod is not making a smooth motion but its getting thrown left and right. Every link in this mechanism has it's own inertia, and every link gets pushed back and forth by the other links, the slop adds up, the banging of the conrods changing direction adds up.
Like the concept Don’t like GM
Thanks, great video, but I'm confused. It makes sense that you want ER > CR to increase efficiency. But then you say the exact opposite for the GM patent. Did you get your efficiency and power positions switched? It's difficult to visualize the difference throughout the cycle.
So baisically gm is pulling a nissan and a toyota out of their hat. More parts = less releable || harder to repair || more expensive to repair || harder to spot bad parts.
Holy mother of bearings
hello sir i'm big fan of your channel which helps to me lot of things to learn about to automotive .so thank you for sharing knowledge hmm , sir can you make a video on engine downsizing and what does it actually and why now a days an automobile companies prefer it first.....i humble request to you sir than you ......
I dont like or trust Gm products.they are known for small vehicles that are over priced and far from fuel efficient.even if this engine of theirs would save me 90% fuel,i would not buy it.
Over complicated and relatively unreliable way of getting around the use of solenoid valves which could give any ratio between compression and power strokes and would not introduce any more moving parts (Actually eliminates a lot of moving parts) and would make a much more reliable and more easily maintained machine. Exactly the same as every other piece of garbage that GM has produced since its inception. Obama should have just let these clowns go bankrupt.
More efficient at converting fuel to power, but less efficient at what you really need,,, moving the vehicle the maximum number of miles over the life of the engine. More repairs= inefficiency .. More maintenance=inefficiency.. Short engine life span= inefficiency
And since GM is doing this engine it probably won’t last very long. If Toyota on the other hand was Perfecting this technology it would be bulletproof
I want a plug-in hybrid twin-charged dual-injected variable compression Skyactiv-X CVT manual side-wheel drive Toyota Civic
Worrying about valves opening and closing with independent control wasn't bad enough...now, where exactly is our crankshaft's position...hmmm. I can't wait to throw a pressure transducer into something like this! So much to be learned. Amazing explanation man. Bring on the new tech! ~Mike
GM still rearranging the deck chairs on the titanic, I see.
I have GM car before never again I will trust their quality.
For years I've been wondering why independent valve control like "FreeValve" and the Variable ratio systems (GM/Inifiniti) are not developed in parallel? They arguably go hand in hand while also being the likely final evolution of ICEs :(
I can't even afford a new car already. Now this extra complexity, never going to work money wise and reliability wise. Interesting idea though.
Your diagrams are so very clear!
Isn’t that the same as Ford’s flat crank V8?
I wonder what Nissan has to say about how GM gave this system an unoriginal name
J Yearr
År siden
That's what I'm saying. Nissan had VC Turbo Altima prototypes 2 years ago
Sounds impressive enough EE but I wonder how you rate this when compared with Mazda's new HCCI/SPCCI engine in the Skyactive X cars?
And here i thought the mazda design was madness.
If there is no circular motion of the main crankshaft anymore, there must be unbelievably huge stress on the connecting rods every time the piston changes direction, because you always kill the momentum multiple times a second. That could work as a prototype, but is definitely not suited for 300k km +. No matter which brand builds it... change my mind.
thank you MAN
Why doesn't American car makers seem to focus on reliability anymore, bad business as can't sell more trash quick enough?
only time will tell if this new engine will be reliable and last years. for those who forget to do oil changes regularly will destroy their engines 🤔
You sure are a great teacher! And take it from an Engineer that just learnt something today because of you.
8:28 dont know why im automatically moving my body and dancing .
Oh, it's an exlink engine like Nissan. It achieves the same goal with different details.
That is already a FAIL.
four new parts, three new pins; seven new points of failure, and seven reasons to switch to electric.
I dont really understand the geometry behind it, but it looks like with this design a parallel "v" engine could be possible. What I'm looking at specifically is how the crankshaft is offset (vertically) from the cylinder. So it might be possible to mirror it over the crankshaft to make 2 banks. Then it would be possible to make it have a single head like VWs VR engines (but not as funky with angled pistons on the head)
hi jayson. may i ask the pros and cons of deleting an egr system in diesel engine, theres plenty of vids out there but your explanations is the only one i trust. thank you
Tom Raptile
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Con: you hurt the environment and your health by releasing more nox
4:36
IDK, seems kinda fragile. This "simplified version" seems to put a lot of stress in that electric moving part. What you guys think?
Funny how companies try to get the last drop out of a combustion engine. The money is better used for electric car development.
Another reason to just go electric. Interesting all the same.
Next video: Top 25 reasons why GM's variable compression engine failed miserably (part 1 of 4)
Most other car companies: hey let's use known techniques that are reliable to increase power and efficiency GM: let's develop something so overly complicated its doomed to fail and still not use multiple values or belt driven cams
Pretty clever but is this tested on any engine yet? Will the pistons and linkages handle 5000+ RPM in just a back-and-forth motion without causing too much wear? How will they balance this engine?
In 12 months, the video on how it didn’t work
Interesting engineering. I wonder how well the components would last long term?
I still think the Saab solution is beter, because less moving parts
Hallo Professor, can you make a viedo about the EVAP System?
This motor is way too complicated a good turbo engine will make more power than this motor because it has forced induction and will cost less than Parts when the thing breaks guaranteed prove me wrong
This motors way too complicated and is not meant for hundreds and hundreds of thousands of miles I don't know why GM is fighting it but they should make a V8 turbocharged it can make tremendous amounts of power and then driving around on 02 no boost be very efficient
Fantastic explanation.
Wow!
SAAB tech...
not only more failure points, but also more rotation mass, worse response and higher center of gravity. despite all that, I still think it is a fascinating idea
This will make a great vehicle to lease and get out before it turns 4 years old. Excellent concept though.
Hey Jason @engineeringexplained, I was wondering if you could help me out with a question about DCTs? (Irrelevant to this video I know but I cant figure it out!) In a common manual/automatic transmission when up-shifting, after disengaging the clutch the human/computer must wait for the engine RPM to drop to the appropriate value for the next gear before re-engaging the clutch. How does a DCT function in relation? In other words how does engine RPM drop at a faster rate compared to a manual transmission to allow a faster up-shift? Many Thanks
Maas Morin
År siden
I dont have an answer for you but couldnt you have a computer actuate an engine brake that momentarily is applied to the flywheel to rapidly drop rpms while the clutch has the engine disengaged?
Repair + mpg = empty pocket. But the tech is great.
is that weird connecting rod movement eliminates secondary vibrations or enhances it?
I had a very similar idea in about 2003... Thinking of forced-induction engines... A couple of engineering buddies laughed at me 😐
GM junk
- i just dont trust the little motor at the bottom. something tells me thatll break every 40k miles and require the body to be removed to get to it... - i imagine this is wholly incapable of handling boost? - why would you need to adjust position at a worm gears pace on each individual cylinder? arent they all supposed to be running the same exact specs as each other all the time? - is it even worth salvaging if the thing ever gets hydrolocked? - the more complicated an engine gets in the name of efficiency, the more stuff oil has to touch, thus the more things have a chance of failure if you have anything happen to your oil at all. if you run small engines without oil and seize them hard, you can take them apart and slap some new rings on the pistons if even needed, hit them with some WD-40 and theyll run again. THIS will cause a black hole if any little thing goes wrong. 2000 subaru forester s, 2.5L N/A 5M... i dont like the complicated thingamajiggers because i cant fix them on my own, or the parts are too expensive
Jason, I love your channel - thank you for your work! I have a video suggestion - the theoretical ultimate efficiency if all patented engine designs were applied to one design (sharing of intellectual property between manufacturers). If only Christian Von Koenigsegg combined freevalve technology with variable compression AND direct injection AND port injection (with a bit of Mazda's spark controlled compression ignition) AND the Koenigsegg compressed air system for turbo spooling AND pre-heated catalytic converters AND hybrid energy recovery... the IC engine would maybe get close to an electric motor efficiency but with all of that complexity. If on a level playing field 2 engineers presented the electric motor from a modern BEV and the best possible IC engine. Nobody would think IC was better. I love IC engines and we'll want to use them for a while longer, but looking objectively I think the industry is moving too slow to compete with BEVs. We need to treat IC as a nice hobby in classic now. If solid state batteries happen, IC needs to die - regardless of whether grid electricity is all renewable or not.
John Gialampoukas
År siden
Or you can look the theoretical cycles and see how much would be a theoretical maximum efficiency.
And after all that work they will use OHV heads.
If it’s anything like every other GM product I’ve owned, it doesn’t work.