New 2 Stroke with valves from Mazda will blow your mind 🤯
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- Опубликовано: 19 май 2024
- Here we will analyze the new patent from #Mazda presenting its new 2-stroke engine with valves. We review the 2-stroke gas and diesel engine and the 4-stroke engine to fully understand the differences.
#engine #valves #piston #turbo #power #Mazda #horsepower #blower #compressor #speed #cars #diesel #2stroke #4stroke #3danimation 
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Mazdas continued development of creative solutions to small engines is really cool to see. From rotary engines to this.
Only problem as i have understood it, is these engines need a GPF (Gasoline Particulate Filter) because these engines produces as many, if not more very fine particles.
This also means that the idea that Diesel should be phased out because they "pollute" more, is now not correct, compared to petrol engines.
@@JohnDoe-bd5szopf is already in use in europe and probably in the states at some point so its not fonna be just a mazda thing
@@JohnDoe-bd5szPPFs are already a thing, petrol particulate filters. Just another thing to go wrong and repair down the line anyway. Call it environmentally friendly if you want but it’s not good for the consumer’s wallet
@@Robdutton91 I agree, but my point was only that now petrol engines also pollute like diesels so the whole "Diesel must die" mob is quite silly.
Especially because diesel has lower Co2.
@@JohnDoe-bd5sz yes you’re right I went off on a bit of a tangent, I agree with you
It's nice to still have a brand that does amazing things.
The best Mazda. I had was a '94 Ranger, 4 banger 5 speed, stick. I got tired of driving it at 300,000 miles and sold it.
It is not often the manufacturers make that kind of mistake.
They are in the business of selling cars. Do you wonder why the dealer only keeps a 8 year supply of parts?
They will sell the new part at 9 years. IF you buy the new parts wrapped around it.
@@warrenpuckett4203that had the Pinto 2.3L Lima engine. Very robust engine.
It would be even nicer if those amazing things were reliable.
This is not very "amazing". I am surprised they got a patent on it. All of it is obvious and much of it has been done before.
In my opinion, Mazda has some of the best engineers in the world. Quite ingenious.
Good to see that Internal Combustion is yet to say its last word with multiple companies trying new things to improve the efficiency.
And a small bonus that would sure please a lot of the car enthusiasts is the sound of a two stroke!
I agree! And these improved internal combustion engines are ideal for use with the carbon-neutral synthetic fuels which are also in the pipeline!
why would it sound like a 2 stroke?
@kenmoncrieff3044 na it wont no expansion chamber and if they produce it will be a pos under performing mazda and be loaded with mufflers probly wouldn't sound nice anyways
@@BIGSMOKE-bl2lq ?? Even without an expansion chamber, 2 strokes have a special sound
@@Minecrafter-uh6qv yea but it gets real hard to distinguish with multiple cylinders and mufflers etc i also would imagine it will be fairly tame compared to a mx bike it will just sound like shit i would bet money on it
I love how Mazda has always been brave enough to step outside the engineering box that other manufacturers stay in.
Yokinihong. Japan research. Wong long duang
Except the EV box?
The key is direct injection. With the fuel only being injected at the last moment, the rest of it is just an air-pump so having some of the intake lost to the exhaust is not a problem.
Indeed, I believe they are using direct injection on snow mobiles (using the crankcase to charge the cylinder so air/oil enters the engine through the ports)
Ya, I always thought Detroit Diesel engines were perfect minus the lack of a turbo, but the ports were the only problem from it being a hungry oil burner like some modern engines from reputable brands, lastly if seems like octane ratings won't matter any more like a diesel engine, possibly a great contender to the Tesla plaid! :)
@@Eduardo_Espinoza FYI ports aren't really a problem... Achates power's engines (which cummins is making a military tank variant) has ports and doesn't burn significant oil.... the difference is all in tolerances and our capability to machine these things today. We use thinner oils also... its also doing direct injection like most diesels (except pretty old ones that had pre combustion injection chambers.
Is that also a commercial engine that's used in a tank, so that it has emissions to follow? I wonder if tanks have to follow any sort of emissions. Also, thin oils are efficient, so more power. Lastly, if it's expensive to make it's harder to commercialize it for the masses. @@Wingnut353
I will look into though, so tnx for that info! 🙂
It's called scavenging.
I remember Toyota doing six cylinder 2-stroke research engine with valves and a blower already back in the 90s
Try 1988
With valves? Direct injected? Compression ignited???
Sometimes a good idea comes too early for it's time. Leonardo da Vinci tried airplanes for instance.
Not like Mazda does in taking it to the next level as they always do.
Orbital Engineering in Australia did this as well. Sold the design to GM who shelved it…
It should be noted that on the 2-stroke diesels on the locomotives I work with, the supercharger has a centrifugal release clutch on the impeller so that when there is sufficient exhaust gas, the supercharger can act like a turbocharger. When the engine slows down, the clutch re-engages so enough air can be supplied to keep it running. It is actually most efficient at WOT as a result as exhaust gas energy is feeding the engine, not the crankshaft. On a smaller scale, this could make one hell of a powerful engine for a car and perfect for a sports car. Rotary replacement incoming?
I can add that very big 2-stroke diesels in ships don't have engine-driven superchargers. They use turbo chargers for normal load and additional electric motor-driven air blowers for low loads.
@@titibobo2000Mazda is experimenting with electric compressors as well
Yes, and those old units are better to run than any of the new stuff with tons of computer controls.
GM 710 I bet, 😊
EMDs
Detroit Diesel had two stroke engines in 1939 where the breathing combustion air never went into the crankcase. They used a Roots blower to achieve positive air induction pressure. This is just a variation of that design with intake valves, instead of cylinder ports.
I am sure this is being done due to size constraints to operate as an apu range extender on EV cars. Operating at a constant speed would eliminate many issues inherent to this design in a conventional application
As would electronic control of the valve timing combined with direct injection! the inherent flaws would be significantly reduced over a fixed timing arrangement and port injection or carburettor for fueling
Nope it's Mazdas sky active x engine in regular cars no hybrid bull shit.
@@needmoreboost6369Mazda has both those in their new sky active engines this is the newest version of that!
Ya, sadly I believe you're right on that one, since that they mentioned the cams are now 1:1 to the crank, it's spinning 2x the conventional speed so 5krpm is red line 10krpm! Racing cam speeds! So to fix that Mazda's gonna have to put super stiff springs for 14k-21k rpm! Yet, hopefully they can commercialize F1 air valve shocks for that!:)
Ok so can we get this but with a oil style catch can on the exhaust with a pump that re puts it back into the fuel to reduce waste ?
Detroit diesel did it starting in 1938 and are still being used off road. You can have everything from 1 cylinder to v12 with 1 block or combine blocks for v16, v24 and so on. It is the longest running engine in trucks. All the way to the 80's and in the 90's for special equipment like fire trucks.
GM Buses also used the Detroit. I have driven many a truck with one of those engines.
@jamesbosworth4191 oh yes they did. For decades. Engines laying on their side. Lol. I sold a 6v71 bus engine a few years ago.
They also do a good job of running away if they get too high in rpm.
bull chips. bro they are still used to this day.
One of the best sounding engines ever built! But fuel efficiency wasn't a strong point. Acceleration was strong, for a diesel, and the power to weight ratio was commendable.
It surprises me how many of these found their way into stationary applications, but they did.
Ground breaking stuff. Mazda is one of the few manufacturers that pioneer new engines.
One of these days, one of their engine designs are going to change motoring forever. It's not a matter of if, just when.
this isnt new.
nothing new here. EMD has had this technology since the 1930's.
Haha yeah "pioneers"
Ground breaking? You must be joking.... it's a uniflow 2 stroke.... been around for years.
In the 60s and 70s two Villiers engineers built an twingle/twin 500cc 2 stroke engine, that used the fuel and oil cooling of a 4 stroke ,but with no valves and a combustion stroke each time the piston hit TDC like 2 stroke. The engine was clean running and powerful, with around 20% cheaper to build than a 4 stroke engine. NVT built a running prototype in the mid 70s but lacked the money to put the bike into production.
Actually 2 stroke aero engines were made with supercharger scavenging & direct injection about 80 years ago, so 2 stroke petrol engines without crankcase scavenging have always been around in some form other. Also it’s possible to use a turbocharger for base rev scavenging. One just has the turbocharger’s axle connected to the crankcase with varible gearing, so it operates like a supercharger at low revs & provides added power to the crankshaft at higher revs, in aero engine circles, called turbo-compounding.
Rolls Royce Crecy
Napier Nomad
Rolls Royce and Napier did this in the 1940s, but turbines made them obsolete for aircraft, pity 😮
The invention in this case is not the supercharged two stroke concept.
It is the valve CAM control that is different here.
@@EvenStar303 Not that. In the patent description, this engine use dual-mode ignition. It uses compression ignition i.e. the diesel engine way in low load and uses spark plug for ignition in high load situation.
I'm glad to see that development in combustion engines hasn't stopped even with current EV obsession
EVs will need range extenders for a long time until the grid is upgraded. This wpuld be an awesome APU in a tiny paclage on an electric, even as a regular portable generator.
@@noname7271 What range extenders.
I drove 3000 miles on a round trip to Italy this summer, and i had NO problems charging my EV, i was even able to just go past the charger it suggested as there was still another one within range.
@@JohnDoe-bd5szThis wouldn't work as well in a sparse wasteland like Middle America.
@@noname7271 Yes but that will change. Not long ago I would have had to go out of my way to get from OK to ND. Not anymore. Not saying we are there yet but I expect it will not be more than a few years. I am keeping my gas cars till then. Will not hesitate to go EV when it makes sense. Middle America IS sparsely populated but it is anything but a waste land. But happy to have the rest of the country think it is.
Mazda should be investing in the future. The Japanese government has been slow to support the adoption of electric vehicles (EVs). This is due in part to the lobbying efforts of the Japanese automobile industry, which is heavily invested in internal combustion engine (ICE) vehicles. Same old story. Think crushing of the EV1.
@@danharold3087 Eventually yeah but distances are greater in North America compared to a European county.
Back in 1973, in Canada , I got to drive (for a couple miles) a Ford tandem axle gravel truck , while the owner rode with one of his junior drivers . He said it was oil injected 2 stoke gas & it sure had some power. I don’t remember if it was direct injected for the gas.
I've long felt that even though two stroke diesel engines have a narrow power band, they were well suited to hybrid drive trains as the CVT makes up for the limited rpm range and the hybrid harnesses as much of the energy dense diesel fuel.
This seems like a great design idea that could also work for diesel fuel.
problem is diesel is done for in the EU due to regulations on emissions. In the netherland there are almost zero new diesel passenger cars for sale
Trouble is, they only make power at high rpm. The noise would be enough to keep manufacturers from using them.
If you've never run an old Detroit, slam your hand in the door, then you'll be in the proper mindset to drive it.
Mazda said there is still more room to develop combustion engines. once they get the ecu algorithms sorted this should be a sweet engine with double the torque compared to a similar sized 4 stroke.
Most engines are between 30% and 40% efficient. I think most are closer to 35%. So there is a lot of efficiency that can be gained from gas engines. Gasoline is a very dense form of energy. They just need to do what Mazda is doing and improve the engine radically.
@@actionjksn We already have 45+% efficient gas and diesel engines developed.... just nobody is building them except for military applications, china also has 50% efficient diesels in production. Also part of the reason current diesels are inefficient is excessive after treatment instead of just cleaning up the initial burn.... it wastes a lot of power.
@@Wingnut353 That's better but it's still pretty low.
Almost double the power because of double the number of power pulses, but not double the torque ( or maybe even any extra torque ) because torque is a product of crankshaft throw ( engine stroke ).
The AFR of 14.7 : 1 is by "weight" and not by volume as stated.
Mass
this idea has been kicked around for many years ,Smokey Yunic had a high output version back in the 70s and Orbital technologies came out with small helicopter engines in the late 80s, BRP had a semi version of it in seadoos for a while as well.
The hard part seems to be the intake- exhaust transition inside the cylinder, but I guess Mazda will take care of that. Sort of a similar idea (which turned out to be a combination of two-stroke Diesel and GDI gasoline engine) struck me almost 40 years ago, but never made the way from my head to the workbench so far...Thanks for introducing the concept!
This actually works in practice on Marine Diesels, so no reason it won't work scaled down. Common rail diesel injection systems have been around for a 100 years and possibly more and yet are reasonably new in the automotive world and came from Marine engines designed and manufactured by William Doxford of Sunderland in England. They were also Opposed piston with tthe top piston acting as an exhaut valve as well as adding power and balance to the crankshaft.
Though I wouldn't advocate opposed piston diesels for automotive use. Car mechanics are completely confused now.
With electronic common rail and variable valve timing, twin turbos it has opened up new designs plu the sensors and ECU's, so I can ee longevity of the diesel engine with a bit of money going into research and development. Just look how far we have come in the last 25 years.
Very nice super clear video with all technicals double checked. Keep it up. 👍👍
Thank you.
@@repairman22 I think, he ment it ironic...🤔
7:10 "One spark per RPM."
One spark per revolution.
One ignition event per cylinder per revolution.
@@Clyde-2055 one ignition event per cylinder stroke... :)
2 stroke that doesn't burn oil is an idea that has been around for a long time. It is common in diesel engines. They use a blower to move the air into a manifold that goes to the cylinders. On that sort of design there often is a port in the side of the cylinder for in take but vales in the head for exhaust. On the Deltic rail engine both intake and exhaust are ports but they use two pistons per cylinder and time them to get the ports to open at the right times.
A turbocharger can be used on such an engine. At high RPM, it pushes air into the blower increasing the air pressure in the manifold. This is a good idea because with less time to purge the exhaust you need to work a bit harder to get the clean air in.
On a piston port, there is no need for there to be oil leakage. The oil ring never goes above the port and the pressure in the port is higher than the pressure in the crank case.
At light throttle, it is a lot better to make the car a hybrid and simply shut the engine down for a while. This lets you use a smaller engine and also gets the engine to be always running more efficiently.
I think these engines like some others I've seen recently will be utilised as range extenders in hybrid vehicles basically used as a very economical and environmentally responsible generator. What a shame Mazda didn't release this 20 years ago instead of the rotary engine but it shows they are constantly looking at improving engine technology.
Pretty sure the only reasonable range extender design is rotary. Fuel efficiency and reliability is not at a premium for those and you don't want it to be any bigger and heavier than it absolutely has to. Otherwise you're just running a plug-in diesel-electric so you might as well lean into it and use a proper big powerful ICE.
Also this superchaged two-stroke requires a supercharger, it makes it even bigger and superchargers don't exactly have great reliability. So that actually works against it in terms of range extender applications. You get maybe equivalent of atmospheric rotary in much bigger heavier package and with the same level of reliability, and it saves, like, what? Half a gallon of gas? In how long?
No.
shut up! we like rotaries! They are the best!
A small and efficient one or two cylinder REX might have a small niche with HEV trucks for towing
@@michaelbuckerswhy would you use a rotary engine when emissions and efficiency are so poor for them? you ideally want the most efficient possible tech that’s a better balance of weight vs efficiency
Been waiting for someone to put this in to production since direct injection started coming to gasoline engines. yay?
Won't sound like a two stroke...it won't be in the middle of the power stroke when the exhaust port opens, won't get that "pop". I'm going with it sounding closer to a 4-stroke, high-revving motorcycle engine.
KTM makes two stroke bikes with fuel injection and oil injection for that matter and electric start...
@@billmalec so?
@@benperkins2929 so, you never stop learning or shouldn't be unwilling to.
@@billmalec What do KTM making normal 2 stroke engines have to do with this ? (hint NOTHING !!!)....
@@billmalec and how does that apply to the sound? hint it does not
i remember seeing a magazine article in the 80's or 90's about an australian guy that merged a few small dirtbike engines to produce the same idea it had a rotary disc valve modified to compress the fuel air and a 4 stroke head and cylinder with the cam geared to run 1:1 it was essentially a supercharged 2 stroke with no ports in the cylinder that used valves in the head.
Orbital?
@@ricardojuarez3614 nah wasn't ralph sarrich he invented the orbital in the 70's
An Australian patent in 1980s used an AIR injector and a fuel injector, eliminating intake valve, allowing 2, 4 or 6 stroke variable cycle engine
I remember this, the company implementing it (in Ford Fiesta IIRC) was called Orbital.
The key piece of “news” here is they figured out a way to get a new patent on some parts of this engine.
I had an idea similar to this but with a V layout, where one cylinder uses reed valves for the intake, and acts as the air compressor for the next cylinder.
Same here.
That has been done, can't remember what it was called but Mazda and Volvo had the engine on the drawing boards in the 70's or 80's. Each piston pair consisted of a normal 4 stroke cylinder and a larger paired one that was larger. I don't think it went anywhere because the "pump" piston was always cold leading to oil pumping past the rings and you basically doubled friction losses and reciprocating mass. Wasn't worth the complexity.
This is similar to the five stroke engine where the exhaust from 1 cyl is fed to another to scavenge more energy.
@@jw-hy5nq .......... This principle was used by Ricardo? ( the "Dolphin" engine was used (successfully) in the early 20th century, also by some other manufacturers - Trojan delivery vechicles having used it successfully till just after WW2.
I came up with the same design when I was 19 years old, preparing for a physics exam. My class mates at the time laughed me off saying that 4 strokes are more than 2 strokes , therefore 4 strokes are better. 😅
lol. ...and after graduation, you see some of those guys at the same industry workplace....at the same starting pay. It's an insult.
You imagined that scavenging system, is that what your saying?, by scavenging I mean the egr system, that's one advanced efi programme.
an 8 stroke would be really cool then... :)
Very informative! I've always found 2 strokes, in general to be quite confusing!
Two stroke is way less confusing
Interesting. There are actually a lot of improvements to the 'traditional' 2-stroke that are worth mentioning as they improve volumetric ratio (milage) and reduce oil consumption - these were developed in the 60's to '90's. Tuned exhaust pipes re-inject unburned charge from the exhaust back into the cylinder to be burned in the next combustion cycle - they can be tuned for variable engine rpm with 'sliding pipes' seen on some racing boats. Loop charging directs incoming charge to more efficiently displace exhaust on the upstroke, improving scavenging and reducing amount of unburned mixture escaping the exhaust port. Exhaust 'power valves' change the port geometry for better efficiency over a range of rpm's. Evinrude/Bombardier had some additional improvements that reduced oil consumption to a negligible level...they had less emissions than some 4-stroke outboards and were able to pass strict emission standards.
構造上燃料にオイルを添加する必要無いンだけど(呆
Always thought this design would be ideal for a hybrid car!
I've been working on designing 2 direct injected 2 stroke supercharged for 2 years. The problem with overhead valves it traps exhaust at the bottom of the cylinder. This greatly reduces volumetric efficiency. The egr effect is good, but reduces efficiency just like typical egr systems. Then needing bigger motor to produce enough power to travel. The reason 2 strokes work is the placement of the intake & transfer ports being at the bottom when the piston is at bottom center. This can be modified to change rpm power output. Same as the intake windows in the piston. Just a piston change can make more low rpm power or high rpm for this reason. The other issue your using only 1 set of exhaust valves which means it has to spin at 2x the rpm as a normal cam would.
Imo the best design is supercharger connected to bottom of cylinder, 2 exhaust cams alternating, & pistons with 2 sets of oil control rings to reduce oil at the intake window. A pcv system (& air oil separator) that can handle a small amount of boost which allows oil under small pressure into the piston when closed/ covered instead of oil going into the intake port. Some oil will be burned but not much more than typical car using oil (like Subaru).
You explain the engines the best.
I think Mazda will produce 2 cylinder version for the mass market since the power phase is similar to the 4-pot 4 stroke.
It's crazy so many people have no idea about two stroke Diesels that worked just like this "new" engine nearly 100 years ago.
They think everything Japanese is "new"
нет,не безумие,
появвилась масса электроники и система FSI
будет соблюдена экология.
2 stroke diesels is nothing like this as they have ports for the exhaust. Only thing that is similar is the blower for exhaust scavenging.
It's crazy that you watched this video which clearly explained the difference between conventional two stroke diesels and the Mazda design and still posted this comment.
@@a64738 2 strokes diesel, having those ports makes them even better as all 4 valves at the top can be used for intake.
I like it. That was the clearest and simplest explanation of a standard ported two stoke I think I've ever heard. That new one seems kind of crazy, but we'll see.
I kinda wondered what 2-Stroke research was doing these days. I sold motorcycles in the’60’s & ‘70’s and had a few 2-Strokes. I currently have a Mazda Miata RF. Maybe my next one will have a 2-Stroke.
Now that some insurance companies have started refusing to insure electric cars and ferries refusing to allow then on board, the combustion engine has a bright future.
The current battery technology is totally unsuitable for cars.
Still got a crankshaft...puts a fundamental limit on the power that can be gained from each power stroke.
If you think about it, the force vector generated by the power stroke is in the direction of the center of the crankshaft when the cylinder pressure is highest. Only the component of the vector that is tangent to crankshaft circle can do useful work. That only occurs very briefly in each crankshaft revolution.
Have you ever heard of crankshaft offset ?? - done for the very reason you cite here.
Sorry for diverting the conversation a little, but It is interesting to realize that the piston "rotary radial" (different from "normal radial" piston engines) - had pistons, conrods and a crank, but were actually true rotaries, (the crank was stationaryl and was attached to the airframe, - the cylinders rotatated around it - so there were no actual reciprotaing parts (just "relative reciprocation") - there were some oscillating parts, like conrods - Main problem was "precession" caused by this rotating mass, it did tend to affect the aircraft when changing direction!! - perhaos it could be revisited as a potential generator?
I appreciate the knowledge, thank you!
Excellent graphics and presentation. Most interesting. Thanks a lot, Colin UK.
The problem is parasitic loss from the compressor. If they can use an electromagnetic clutch of some kind to switch to a turbo when exhaust gasses are built up, it will be much more efficient.
Like a shrunken system like the one used on EMD big diesel engines.
It drives the turbo mechanically of the crank until enough exhaust gases are generated to spin the turbo faster than the crank can.
@@GIGABACHI yes exactly, like that.
you still need lower exhaust pressure than intake pressure as the intake and exhaust are open at the same time, more than just overlap
Parasitic losses are inherent with any forced induction engine. Not just this one. The losses are more than compensated by the additional power the blower provides. Hence overall efficiency increases.
A turbo would also put additional back pressure on the exhaust stream which is a disaster for a 2-stroke. So no that's a terrible idea.
Although this engine is currently being developed to run on normal fuels, I wouldn't be surprised to see it being adapted to run on hydrogen. The 16:1 compression ratio would be ideal for hydrogen injection since it has a very high "octane" rating and doesn't suffer from knock problems.
Hydrogen is NOT a fuel.
You can not mine elemental Hydrogen.
And to create Hydrogen takes electricity, so you are actually ruining the efficiency of the system with conversion losses.
Hydrogen is an inferior technology, that is why we don't use it.
Plus storing Hydrogen is very dangerous.
It needs to be kept under 5000psi pressure.
And it leaks through every other material, because Hydrogen is the smallest atom.
Hydrogen tanks are typically 4 times bigger then Gasoline tanks for the same amount of power.
Do some research before you are promoting nonsense on line!
Hydrogen is a poor choice for a internal combustion engine. Poor storage capacity, and expensive to store and transport, and, when used in an engine, reacts with the metal parts making them brittle and failure prone. Not to mention your options for creating hydrogen are either fairly dirty (fracturing methane) or inefficient (electrolysis) so the whole idea of "only emitting water" is fairly dead on arrival.
Not to mention the whole "the only emissions are water vapor" is false anyway, you still produce side products, and in an efficient hydrogen engine, you also produce nitric acid, because of the high temperatures. Basically, it's a meme fuel, you're much better off finding efficient ways to close the fuel cycle for normal hydrocarbon based fuels.
@@jttech44 All correct.
Stupid people don't do any research they just parrot fake YT videos they have seen.
We are using Fossil fuels because they are the best option.
The problem is not the fuel as fare as pollution, and CO2 is NOT a pollutant.
The problem are the cheap engines that burn dirty and does not last very long.
We could make clean burning engines that last 10 Million miles.
But we don't because there is no profit in that!
@@jttech44 Unfortunately your comments are either hopelessly out-of-date or factually incorrect. I'll go through them one by one.
Expensive transport and poor storage. Out-of-date. Hydrogen can now be generated at the refuelling point and compressed to energy densities comparable to diesel fuel. All that is needed is water and electricity.
Hydrogen causes embrittlement in engines. Factually incorrect. Embrittlement occurs at much higher temperatures such as those used in welding. There is no reaction of this type at internal combustion engine temperatures.
Hydrogen production is dirty or inefficient. Out-of-date and factually ambiguous. Hydrogen from methane is cleaner than burning fossil fuel to generate electricity for EVs. The by-products are captured so from that point of view it is 100% clean. Like the fossil fuel based electricity made for EVs that will be phased out over time as more point-of-sale hydrogen generators are built. Hydrogen from electrolysis is now more efficient than storage of power in batteries and will continue to improve.
Hydrogen produces nitric acid. Factually incorrect. This is based on engines which were converted to run on hydrogen rather than designed to run on hydrogen. JCB, a major UK farm equipment manufacturer, have produced an engine of about the same size and power output of a diesel engine. Although it does produce some oxides of nitrogen, even without any filtering this is at about 3% of those produced from the most efficient diesel engines after filtering. With filtering the output is literally just water vapour. Why have they built this? Because at times agricultural vehicles (and others) need to run 24/7. Except for refuelling which A) takes place in minutes and B) can take place at the work site. Even with comparable charge times an EV still has to go the the recharge point. But the primary reason was the weight. Agricultural EVs will weigh 50% more than current or H2 ICE vehicles causing them to sink into soft farmland.
Roadside refuelling stations for fossil fuels can typically refuel 12 to 20 vehicles at the same time. In order to service the same number of EVs at peak times that will have to increase to between 60 and 100 charge points for a charge level which probably won't even let users complete their journey. There are zero plans for this to happen. Look at the queues already at some of these charge stations. Dozens, soon to be hundreds of vehicles waiting for hours to get recharged. And that's now. Wait until it's a dark cold winter's night and your vehicle doesn't have the range to get you home. With no heat in the vehicle because the battery is empty. And the same is true for all the other poor souls waiting for their turn to get charged, there will be hundreds or even thousands in the same position. Coming soon to an EV near you. But hydrogen is a meme? OK, if you say so.
16:1 may be the mechanical compression ratio, but the dynamic/effective compression ratio is much less
I am wondering if - since it has many similarities with 4 stroke engines - it would be possible to use such a design and have it switch between 2-stroke and 4-stroke mode. The SkyActive-X engine has a limited rpm band where it can use compression ignition. Perhaps if you can switch between 4-stroke and 2-stroke mode, you can use the 4-stroke mode at low rpm and switch to 2-stroke mode to achieve higher output. This would allow you to use a smaller engine for similar output and hopefully high efficiency at the same time.
This would require non-mechanically driven valves (hydraulik, pneumatic, electromagnetic drive), those are out there for quite a while now.
The variable timing of exhaust valve with engine load is genius
Yama exup
This is really cool how they integrated so many types or systems into 1 ,seems like it may be a night mare to repair or diagnose. Really curious to see how it works in a real life scenario as well as longevity.
why would it be a nightmare to repair? It consists of the exact same parts as a regular 4 stroke supercharged engine and has no additional mechanical complexity. It's arguably simpler than modern turbo 4 cilinders because it doesn't have a waste gate or even a turbine.
Not so much a nightmare. Would definitely be more difficult to diagnose, considering it has characteristics of both gas and diesel engine as well as 2 and 4 stroke. Compression and spark ignition.
I have been thinking of a design like this for ever but never had the funds or machinery to try to build it 😑 but fun to see it 😁
Thats really clever. Using exhaust gas scavenging to essentially reduce the effective displacement, but retain a large expansion ratio.
Its amazing what has been accomplished with the old piston engine over the last 40 years to make it powerful, reliable, efficient and relatively clean burning.
Cool concept. For those of you doing the math at home: Your 2L engine is effectively a 4L engine if forced air at 15psi. With this, that 4L is now power equivalent to an 8L engine due to twice the power strokes. As an extra bonus, if the dead volume of the exhaust is oversized to allow mixing, the "belt driven compressor" (supercharger) and timing can be adjusted to mix extra fresh air into the exhaust stream at lower RPM, make the emissions look better (except the unused O2 would be high)
And particles.
The higher compression makes particles just like diesel cars, this is why they now have to fit GPF's to petrol cars.
The "Diesel cars are polluting way more" mantra has been shot to high heaven with these engines.
@@JohnDoe-bd5sz interesting!
FALSE. oversimplification
It seems like managing AFR is going to be the most difficult part of this engine, assume it'll just be managed by mointoring the variable cams and the exhaust gases.
Can't help but this this technology would be better suited as a diesel so AFR isn't an issue.
We have computers to manage that
@mennims computers aren't magic, they need inputs to work.
If they want this to be fuel efficient and use air to purge the exhaust gases, it'll be no easy feat to keep the stoichiometric ratio.
Hence why diesel would be the easier fuel choice.
@@MegaGouch I'm a software engineer with electrical engineering experience and mechanical experience. Its possible and not incredibly difficult.
@@mennims Cool. What sensors would you use?
@@MegaGouch I knew you were going to ask this disingenuous question 🙄 you're right, we don't have sensors to measure air flow, temperature, pressure, humidity, cam position etc... All completely new concepts. I'm sure Mazda just wanted to patent a mechanical device they had no idea how to control with a computer. You're right, just switch it to diesel and now it's more realistic 🙄
Well done. I've been wondering about this for a long time.
Pretty sure that using the incoming fresh air to flush the combustion chamber is an old concept that's been successfully implemented a few times. Pretty sure one of the Vespa scooters did that, albeit with a different mechanism, using some clever geometry with the face of the cylinder. Using a compressor on the intake might introduce more wear spots that would need attention, but nothing totally engine-breaking.
Mazda did this with their Miller cycle engines in the late 90's
The main problem here is not technical but the production cost. The supercharger is more expensive than the engine itself. You can make a twin four stroke engine with turbo and intercooler for the price of one supercharged 2-stroke engine.
I'm quite sure that it's all party hats, sparklers, party poppers, soda and cakes in Mazda's engineering department, at present. I've got a sneaking suspicion that the night is going to come to an abrupt end when the finance department and accounts payable turn up, however.
That said, though, it's not exactly like Mazda don't mind putting it all on black when it comes to R&D, so who knows. Look how far they kicked the Wankel rotary down the road?
And the Skyactive G ( I think it's the G?), that's now in production.
But there's no way in countering your observation regarding cost. It looks very expensive to produce, that's for sure.
when roots superchargers started to cost more then engine? you need supercharger that can scavenge the volume of 1 cylinder (engines never fire all cylinders at once), so it wont be big nor expensive
@@m1sst4k37 It needs to scavenge N cylinders worth of air per revolution... no way around that. You can run the compressor at 4x the speed of the engine but it probably won't be reliable so they'll run it lock step with the engine most likely and disengage it once turbo boost pressure has built up at mid to high RPMs. Its possible they could design the engine so idling is infrequent so the short lifespan of a 4x speed compressor isn't an issue since it can be disengaged after turbo pressure builds. If you do that you can only sell the car as a hybrid though since a flywheel integrated starter would be required if you are shutting it down after short idle periods.
@@Wingnut353 it needs to scavenge N cylinders per revolution only if you have more then 4 cylinders, and you dont need big supercharger to scavenge about 800cc per two cylinders - 400cc supercharger with 2.0:1 pulley would be really really small size, something like Aisin AMR-500 would handle this no problem - check how much it costs new
P.S and we not considering the fact that you can do 2stroke with size about 1.0L and still got much more power then 90% of 4 stroke 1.6-1.8 NA engines, and to scavenge 500cc per revolution it would require tiny supercharger
A blower on a 2 stroke just moves air through the engine with no "boost" pressure. You can add a turbocharger to that same 2 stroke and apply boost to get more torque and power. That system was used on Detroit diesel engines starring in the '80's. The sound of a Silver 8V-92 winding out will curl your hair!
Actually the exhaust port(s) is uncovered a couple of crankshaft degrees before the transfer port to allow cylinder blowdown. Otherwise the residual pressure in the cylinder would further pressurize the crankcase and possibly ignite the intake charge.
Thank you. It's nice to have at least one qualified response.
Same thing in the Detroit diesel, the exhaust valves open just *before* the piston goes below the intake ports to let the majority of the combustion pressure start moving out the top of the cylinder before intake charging.
Port timing in a two stroke is everything.
It is always nice to see some metrics when a new concept engine is proposed.
I'm pretty sure stihl has a grass trimmer 2 stroke with valves on commercial line up( I had to fix a few) used rods to lift the valves not a timing belt or chain I see on the video
That was my idea a long time ago. The problem with this engine is that cams are rotating the same speed as crank. So the valve float will appear at ~4000rpm.
Another thing is that you don't really need a supercharger for it to function, you can pulse/scavenge it through valve overlap (except it is then very hard to start) and can even use a reed valve.
Mabey use like a desmodromic system
@@dirk-jandekrijger7303 That could help but then you have the inertia of the desmodromic system to contend with, which could affect engine balance or induce resonance at certain RPM ranges that could cause damage.
Might be a smarter idea to go the F1 approach and use a Nitrogen filled air spring. Alternatively this could be a very good usecase for Koeniggsegg's FreeValve tech.
@@dirk-jandekrijger7303 motorcycles happily rev to 16k with normal valves. There are bikes like the zxr250 that rev to 18k with normal 4 valve dohc configurations. It can be done.
9k rpm without valve float is perfectly adequate for a car engine imo.
Likely won't be an issue, they're probably going to run these as EV range extender engines and will likely be at a constant RPM anyway.
Fellow 2strokestuffing enjoyer
The 2-stroke engine, but with a 4-stroke twist
Aka it's retarded. Seriously though this engine stops short of actually being good, to get there we need a 2 stroke opposed piston engine that eliminates the complicated head.
Fantastic! Now I just have to figure out how to fit one of these in a bicycle frame…
Excellent video, very easy to visualize and understand the basic concept.
Not used in cars? Detroit two stroke diesels would like a word with you. Also you don't need a belt driven supercharger anymore just use an electrically assisted variable vane turbo.
I don't think a turbo would work in this application, would it? 71 series Detroits used superchargers as positive pressure was required to run the engine at low loads, which turbos aren't capable of. Keep in mind that electrical assistance on a turbo charger is only used to maintain compressor speed when there is no drive being supplied by the exhaust.
Electrical assistance is about reducing lag time and spool up, it's not used for compressing the mixture.
@@davidbrayshaw3529 It did for Detroit, IIRC only the 71's have a mechanical Rootes blower, the others live quite happily with turbos.
But we need to be a little more specific and pedantic, there is a difference between scavenging and supercharging, the Detroits are scavenged, generally this is accepted to mean at the onset of compression the cylinder pressure does not exceed about 1psi, above that it is supercharged.
Are there 71 series that substitute the blower with a turbo? What you're saying makes perfect sense, with regards to scavenging as opposed to increasing air density.
You might be interested, in aviation, turbos are commonly fitted to piston engines in order to maintain sea level air pressure at high altitudes. If I recall correctly, this was called turbo charging. If the pressure was increased above the air pressure at sea level, from memory, it's called turbo super charging. Two totally different things.@@572Btriode
I think most motor enthusiast engineers have been sketching on similar ideas. I know i have.
This is ancient for deisels. What makes this possible for petrol is the direct injection system for this type of fuel.
I used to work on Detroit Diesel engines back in the 80s, the V16 had 4 valves per cyl, superchargers and two turbos, the injectors were also rocker operatedi
, imagine setting the tappets😕
Thanks, that was a good presentation.
My version of a 2 cycle motor was: two eccentrics on a crank for two connecting rods in apposing horizontal cylinders that fire at the same time eliminating the need for Babbitt bearings, so it can use roller bearings to reduce friction.(increase roller length for extra strength). A large third cylinder going up that compressed & cooled intake air. Then one injector by one large intake valve & 2 spark plugs per cylinder. Exhaust port was at bottom of piston stroke as a normal 2 cycle has. Over head cam was gear driven using an aluminum hub & spokes with a steel tooth ring. Add idler gears to reduce gear diameter if needed. For bigger engines add cylinders in pairs. Crank case has a normal 4 stroke gear driven oil sump pump. Air cooling fins every where with water cooled heads. A 4 cylinder motor would have 2 vertical intake cylinders one piston going up as the other goes down, & separate crank cases would not be needed. I wonder if a rubber diaphragm would hold up. Magneto spark system has magnets mounted on crank case plate and the 2 coils go around, so apposing force Eddie current magnets don't electric brake fuel efficiency and the coils spark just jumps a gap like a distributor cap does. Spark advance just turns the plate the magnets are on. To get power at a very low RPM we fire after TDC. I give my idea to the world, you can make it, use it, sell it, but not own it, cuzs it's my intellectual property. 11-25-2023. Invention 743 is a magnet on a springie flat bar with a coil on each side + 4 diodes. Mounted on the VIBRATING heads, the magnets get going by the coils which produces electricity 4free. A bunch of them in a row with a cover is a power bar.
I forgot to add that the idea is to make an engine efficient like a bicycle, which has limited power. A real man can produce 1/3 horse power or so, yet can do 40 mph on a bicycle. A Honda 50 sport is 5 horse and does 60. It seems all motors just add larger cylinders to compensate for wasted power at a fuel efficiency cost. So my design has 2 cylinders firing at the same time, one pushes on crank above the main bearings and the other the below so they counter each other so mains don't need to be difficult to turn babbit bearings designed for maximum pressure, cuz there is no pressure. Then the crank can be flat plates on a main shaft to hold the connecting rods so that internal wind resistance is smaller. Electric breaking with spinning magnets next to metal that conducts electricity can loose more power than people understand. Take a motor out of a direct drive washing machine, short the output wires and try to turn it. You can't turn it at all. It is electric braked to a complete stop, or very very close. I forgot to add that a turbo charger could be the fix for 2 cycle stuff. When the exhaust port vents,the fan blades get a blast and as the pressure decreases the blades could cause a needed suction using the fly wheel effect. Then the intake air pressure buildup it creates on the other side can puff into the cylinder as the valve opens pushing out more exhaust. A turbo charger would eliminate the need for a vertical piston pumping intake air. Fuel injects as the exhaust port closes and you avoid fuel waste. The oil in the crank case eliminates many normal 2 cycle problems like mixing fuel+lube & pollution. Hot oil can be used for heating the cab which cools the motor. Also the Peltier Seebeck effect modules can produce electricity from it's heat as it heats the cab. A thin plastic type solar panel on the van's roof could help eliminate the need for a standard alternator, which uses electricity it produces to make the spinning magnet that produces the electricity. It's an E-brake waster. The vibrating magnet on a flat bar producing electricity thing could be on the suspension also. And once I got a speaker magnet a spinning like a donut on a string and held a degauzing coil off a tube TV up to it and it produced more electricity than any other magnet coil combo that I ever messed with by a lot. The coil was 8" diameter small magnetic wire is all. So if multi coils surrounded a spinning cheepo magnet in a plastic housing you would have an efficient alternator that could be engaged when needed? I like cast steel/iron cylinder sleeves myself. A standard cam & a pull rod design might be the right route to go if valves floating could be avoided. Could the design burn diesel, or waste veggie oil ? Avoid copper in the fuel system and it would burn WVO without the self destruct part ? WVO eats copper with a green crust buildup crap causing all connections to leak over time. Envision X-engine in a longer narrow low mini van designed for low wind resistance, burning WVO on the freeway with 8 passengers in a taxi cab going from the airport to small towns. Americans buy bigger trucks every year with beds so high you can't load anything in it. Stupid is as stupid does. I had a free 3/4 ton Nissan SE-V6 once & it was great. Any way, there is something to ponder.
I think fist valved 2 strokes are now 100 years old
Wtih Compression ignited and ditect injected?
Old ideas often only failed because of technological limitations of their time. I think almost every old forgotten engine format should be revisited again and again just to make sure we don't miss out on something!
@@djhrjeiwhri most people rush to comment without watching the whole video
So true.@@clevernduruza8624
@@IrishSpyHD60Fairbanks Morse never failed
The idea came from Ralph Starich an Australian engineer who developed the Starich Orbital Engine in the 1960/70s in his orbital engine the 9 sided rotor orbited like a planet sun relationship , it used this two stroke system of valves and a blower exactly like this is , it was installed in cars in the 1970s a Ford Cortina as Ford was involved , but the problem was sealing the vanes or orbital pockets , the rotor does not turn only orbits the crank, and the other problem was fuel injectors and pumps not being high pressure enough back then , computer engine control has now caught up , Mr Starich sold the patents to Ford who were working on a small two stroke triple engine in the 1990s , Mr Starich kept the patents on the direct injection / valve idea and sold them to Evenrude Outboard Motors who were developing a two stroke V6 with OETI orbital engine two-stroke injection but four strokes took over the market , I would say Mazda has recycled Mr Starich s patents and or bought them as this is exactly his original idea for the Orbital motor , fact is if working the Orbital Two-stroke would have changed cars for the better , the one in the Ford Cortina in the 1970s was only 14 inches in diameter, 4 inches thick and weighed 60 kg, had a power output of 221 HP and 267 foot pounds touque at 5500 rpm from 1.8 litres . That was a single rotor , he could have stacked them like the 13b or 20b Mazda Rotary's , this was good power back when V8S had about the same power from three times the displacement and 5 times the weight
True the Orbital 3 cylinder 2 stroke was supposed to debut in the 1991 model Ford Fiesta but it didn't happen ford also worked with lotus on a high performance version but that never went into production either..maybe Mazda will do it finally.
@@davenorman8251 true I heard the same , yes maybe Mazda will
Maybe you didn't know this, but Mazda and Ford worked closely together and when they parted ways, Mazda took many of these things with them and further developed them with modern technologies.
Not sure about today, but I believe Ford owned as much as 25% of Mazda
@@johnschreiber1574 That is correct, but since I think 2015, Mazda is no longer part of Ford
Since this needs the compressor, how is it started? Or does it start inefficiently until the blower is going?
Motorcycle Honda CRM250AR (Active Radical) uses a similar technology during idle. This was in the late 90s. Way ahead of its time.
In a hybrid and EV obsessed world, I respect Mazda’s commitment to the internal combustion engine.
Henry Ford almost used this design in the early 1900's except without the blower.
Probably couldn't get it to run well enough for it to be usable.
it would not work without a blower@@jamesbosworth4191
Excellent idea especially leaving part of the exhaust gasses in place to bump compression and maximize energy pulled from.each drop of fuel
My uncle made a 2 stroke small block Chevy way back I'm not sure when I'd have to ask my dad it was way before I was born so I would say sometime in the 70s or 80s but he ground his own cam on a lathe and setup a double points distributor it also runs a blower pretty sweet and one mean engine at the time he said he tried to patent it there was one other V8 two-stroke out there that a Japanese guy made and patented but his didn't have valves. He tried to get some type of funding without someone stealing his idea to patent his idea and never happened but we still got the tractor he passed away some years now
0:53 That's also the reason most 2 stroke pistons have a "ramp" type of shape to them to help deflect some of the fuel mixture up the cylinder and not just shoot straight across and out the exhaust
My Yam RD350 (1974) had virtually flat pistons.
HOWEVER I have heard of deflector piston 2 strokes as in the Scott Flying Squirrel
@@g8ymw Is correct, Two strokes have been domed pistons and loop scavenged on the Schnuerle principle using angled port apertures for many a long year now.
Along with various tricks to alter the exhaust port timing, like the later RD 350 YPVS with servo driven valves to alter the port height tuning. My daughter had one, quite exciting. . . . . . . . . .
On 2 stroke boat engines ?
@@g8ymw My RD 350 got reed valves and the exhaust ports widened and moved up 4mm.... turned it into a high reving beast. The hardest part was calculating where to put the ports in the bottom of the piston skirts. Thought about doing the same to a Kawasaki 500 triple but chickened out...LOL!
@@ajwilson605 Reed valves were standard on an RD.
Can't think why you chickened out on that Kwacker.
Nothing to do with the power band so sharp you could peel spuds or the rubber frame lol
Its a good idea but no doubt you lose some efficiency driving the super charger (which is more than pumping losses of a conventional 2 stroke). Of course having a smaller capacity engine should help with fuel efficiency so will be interesting to see what fuel efficiency ends up like. As far "Do I think it will delay the arrival of electric cars ?", I think the answer is not significantly as I think that the horse has already bolted (in a lot of countries EV sales already outweigh ICE sales), but maybe it will help Mazda hang in there.
This is so cool! Mazda not giving up on innovation in combustion is so awesome, quite the feat of engineering!!!
That is pretty cool! So no oil burn and no unburnt fuel, all whilst being pretty efficient?
Don't forget electric cars are remote combustion vehicles. Remote meaning getting electricity from combustion power station.
Not to forget either that a great number of them are thus coal powered. . . . . . . . . . . . .
@572Btriode Not to forget that they are STILL more efficient than Diesel because the Coal Stations are close to 90% thermal efficiency due to higher temperatures.
Even if all EV power was coal originated, it surpasses Diesel for efficiency as well as keeping dangerous particulates out of high population areas.
@@dnomyarnostaw Indeed so, but you do have to factor in both the transmission losses to get electrical energy to the vehicle socket and the energy/pollution budget of getting the coal out of the ground and into a power station. The electric vehicle has the penalty of carrying the significant battery "ballast" around with it, sadly at the moment batteries do not have a very good power density compared to liquid fuels.
IIRC, two UK universities have separately made very detailed studies of the energy and pollution budgets to produce electric cars and the near identical IC powered variants. It transpires that the budgets are equal at between 80,000 and 100,000 miles of use with the EV then being superior.
Provided you do not need to replace the battery.
@@572Btriode the US generates more renewable electricity than coal powered. www.eia.gov/tools/faqs/faq.php?id=427&t=3
Not all of it. Over 20% is not generated by combustion. www.eia.gov/tools/faqs/faq.php?id=427&t=3
This engine should really have "freewalve" electromagnetic valves as it will solve a lot of problems like valve float at high rpm and the excessive wear you get from the cams running so fast.
Fully agree with you there but if it permits space & money. Mazda is a dying car company, even though you see many on-Road, they have a huge problem with their Name having negative stigma for years of producing rubbish. It will be a tough comeback.
Or pneumatic valves?
@a64738 As do the massive 2T ship "cathedral" engines, the exhaust valves are hydraulically driven and the charge comes from a turbo, to overcome the low revs, low gas flow problem of the turbo these are electrically driven until over 50% power when exhaust flow is sufficient, not a problem for a ship that spends days at a fixed 75% ~ 80% power setting.
The design definitely seems like it works but im sceptical of the reliability cuz air needs to be forced into while the piston is undergoing compression so you need high boost but also need more precise tolerance i guess
& super chargers have high parasitic losses, I'm not sure if Mazda chose a roots types blower like in the animation but it doesn't help for gains stand point.
Optimistically, they can put an electric center fugal super charger/turbo for that, turbos have gone a long since. Maybe they can do a bi turbo setup like the recent 2024 production i4 diesel sprinter van from Mercedes. 🙂
this is a problem detroit diesels solved like 90 years ago... also you can bypass the blower essentially free wheeling it once turbo pressure is high enough when the engine is under load.
It's funny enough to see one sample video from the Czech Republic (white V8 BMW) and the other from Argentina or something ... but the second clip showed a JAWA 350 - a historic motorcycle made in the Czech Republic (then Czechoslovakia) and fairly nice one :D That JAWA is also two-stroke btw ...
There is a pretty big downside to the idea of valving a 2-stroke like this, and that's valve float with larger displacements.
If we take a normal, say, 500cc single cylinder 4-stroke engine, its valvetrain speed is timed in a 2:1 ratio referenced to the crankshaft. So for every turn of the crank, you get half a turn of the cams.
If your 500cc engine started experiencing valve float (where the valves are incapable of closing in time due to their inertia) at, say, 9,000 RPM, then using a similarly sized and spec'd valvetrain on a 2-stroke variant of that same displacement engine would half your peak engine RPM and you would be restricted to keeping the engine below 4,500 RPM. This might not be so bad if you tune the engine for peak efficiency close to this range or the engine has a high torque output, but if it's a small over-square engine that needs high piston speed to produce power then this is going to become a major problem if you want any degree if power from the engine.
That said, Formula 1 could be a strong starting point for where to get a valvetrain that can be spun at those speeds. Most F1 engines can spin over at 20,000 RPM meaning their valvetrains can take 10,000 RPM without experiencing valve float no problems whatsoever. If we're able to affordably implement the air spring system that they have in these engines then that would go a ways to making an engine that can rev high, produce good power and not shred itself to pieces.
The other alternative would be Koeniggsegg's FreeValve system, since that uses an electromagnet to control the valves, eliminating the camshaft. You can also electronically control the valve timing, duration and lift with this technology, which means you can potentially reduce the chances of valve float ruining the engine by reducing the valve lift at higher RPMs. This could potentially even be cheaper than the F1 air spring systems, as they also don't require sodium filled valves, you get rid of a load of air springs, you ditch the cam shaft, bearings, pulleys / chains and all you need to replace it with is a series of electromagnets and a sensor wheel that detects the engine RPM and timing.
FYI, the 20k+ F1 engines used pneumatic valve springs, not sure about current 12-14k engines.
Might work since we have compressor already, but might be cranky (:-p) at startup. :D
why not keep the cam spinning at half the speed as the crank but have to lift profiles on both cams 180 degrees apart?
@@MarcMonson You'll still run into the same issue because the float doesn't occur as a result of cam speed.
Your valves have inertia (in ELI5 terms - that's resistance to being moved and changing direction - It's the same force that slams you into the back of your seat when you accelerate hard in a car, or stops silverware escaping the tablecloth if you can rip said tablecloth from beneath the silverware fast enough). This inertia increases the faster you try to move the valve in the head right until the point the valve's inertia is enough to overcome the spring's closing force and the valve hangs itself open for slightly longer than it's supposed to be. The valve momentarily stops following the profile of the cam lobe during a float, so reducing the cam speed and adding an extra lobe won't do a lot to solve this. It's still gonna be pushed 4500 times a second and float from the raw speed of which it's being opened and closed.
In minor cases (e.g in a non-interference engine, where the valves and piston don't occupy the same regions of the combustion chamber) this would be noticeable as a roll-off in power at high RPM or breaking up / stuttering. In the worst cases (e.g an interference engine, where the valves and piston occupy the same regions in the combustion chamber), this can lead to the piston smacking into the valves, either bending them and causing the engine to run rough, or if you're super unlucky they will snap and cause some major carnage in the cylinder.
@@MarcusLindblomSonestedt78 Precisely what I was referencing.
The older F1 V10s used sodium filled valves for improved cooling and pneumatic springs to cut down on weight and also prevent resonance in the valvetrain building up and causing valve float. Not super cheap to implement but the glorious roar of those engines while being ripped flat-out down a straight is all the info we need to know about how well it worked! :)
Not a problem, you'll just need ramp angle modifications on the lobes vs a 4 stroke coupled with higher spring rates. A 5000 rpm redline on this engine would produce *double* the amount of power pulses vs a 4 stroke at 10,000 rpm🤯
The stepped piston two stroke engine will blow your mind more, far simpler, doesn’t need valves and doesn’t burn oil either. Developed in the 1960’s by Norton. Anyone interested can see an example at the National Motorcycle Museum in Birmingham UK.
Thanks I'll check it out......
I really hope this works well with efuels, so we can continue to use this promising technology in the future.
And how fruel efficient would it be compared to the Skyactive gasoline technology?
Great research and video.. being a licensed technician for almost 50 years and I've always said the 2 most efficient ICE have been either the rotary or 2 stroke.. this is absolutely brilliant and should change the ICE if it goes into production.. i hope they stick to it...
Damn, I’m a home-brew engineer and I’ve been trying to do this for years. I generally think opposed piston or multi-cycle engines are the future, especially diesel.
I’m generally not a fan of Mazda I’m the last 20 years, but they have guts to try new things, like how VW used to be. I like Toyota and Honda but they’re reputation is too good to try new things.
What kinda of opposed piston engine? Like boxers and flat engines or the ones with the ports in the middle of the 2 pistons? Toyota is trying hydrogen, which I think is not a very good idea since a fuel cell is far more efficient, but at least Toyota has that swirl air charge technique in their newer engines. 🙂
Nvm not boxers and flat engines!
@@Eduardo_Espinoza like Achates's powers engines... the are diesel multifuel capable also. They demoted an f150 gettin 37mpg a in 2018... and beating 2027 emissions standards. The simplest way to do it is with 2 cranks... with the pistons pointed towards the center, but you can also do an arrangement like a commer knocker engine if you want to avoid the 2nd crank (it adds other complexity though).
Honda has been onto some cool shit lately with small block v8 boat motors that have vtec. Really hoping they get stupid and put one in something with wheels.
Detroit Diesel has had this from the begining on thier engines.
Detroit diesels have ports for the exhaust, not valves, big difference... Only thing that is same is the need for a blower for the exhaust scavenging.
Valves for the exhaust, cylinder ports for the intake. @@a64738
2stroke collab with 4stroke + diesel = too good to be true 🤤
Fascinating design. Seems so simple but I'm sure was anything but that to build.
This has a usable power range from 100 rpm all the way to 120 rpm.
Do I think it will delay the arrival of electric cars ?
I sincerely hope so !
Correction, most big ships use a turbo, not a super charger. Even the ship Madid Mærsk you show, use 2 MAN 8S80ME C9 engines that are both turbo charged. Even some other of the videos there's a turbo charger.
Compressors work at low RPM, yes in cars, where idle is like 800 RPM. But a ship where max RPM is at insane 80 RPM, it makes up with the insane cylinder volume, where a person can stand inside the cylinder. The turbo only spins at 2000RPM and there's most likely several turbos.
Yes. Its true. I Was referring to cars when describing 2 stroke diesel.
Ships have space for auxiliary starting compressors. Today cars can have electric turbos.
Cool, thanks for the interesting video! Definitely going to be interesting when you start seeing these cars on the road
4 stroke engines waste intake charge out the exhaust too. It's called overlap and is as essential as in a 2 stroke gasoline engine.
They need electohydrolic valves instead of camshafts
Already developed... too expensive. Nobody wants to pay supercar prices for their engines.
Is the tuned pipe part of the setup ?
On a piston ported 2-stroke engine you certainly can change the position of the ports. By raising or lower them through machining you can affect performance radically. In racing we called it quick-timing. This has been known since the 1950s but since most of you grew up with the two-stroke engine being banned, it's akin to NASA not being able to do something they did in 1969.