**The Skyactiv Engine: A Comprehensive Overview**

The Skyactiv engine is a cutting-edge technology that has been gaining attention in recent years, particularly among enthusiasts of high-performance engines. In this article, we will delve into the world of Skyactiv and explore its unique features, components, and application to rotary engines.

**Rotary Engines and Spark Ignition**

One of the key differences between a rotary engine and a traditional piston cylinder engine is the spark plug configuration. Unlike piston engines, which typically have one spark plug per combustion chamber, rotary engines often feature two spark plugs per combustion chamber. This design decision allows for more efficient combustion, as the flame doesn't have to travel as far to ignite the air-fuel mixture.

By having two spark plugs, the engine can create a less lean air-fuel mixture next to each spark plug, which relies on compression ignition. The surrounding area is compressed, and the pressure increase creates a quicker combustion process. This results in better efficiency and power output. However, as the engine reaches higher RPMs and loads, the Skyactiv engine switches to traditional auto-cycle operation, using two spark plugs for ignition.

**The Importance of Air-Fuel Ratios**

Skyactiv engines require a significant amount of air to achieve high air-fuel ratios, which are critical for maximizing power output. If too much fuel is injected, it can lead to reduced efficiency and performance. The supercharger plays a crucial role in providing the necessary airflow, allowing for leaner combustion ratios and improved emissions.

By increasing the air density, the Skyactiv engine reduces combustion temperatures, minimizing nitrogen oxide emissions and improving overall efficiency. This design choice also enables the engine to extract more energy from the expanding air during combustion, resulting in better power output.

**Pressure Sensor Optimization**

The pressure sensor is a critical component of the Skyactiv engine, as it plays a key role in optimizing ignition timing. By monitoring the pressure spike caused by compression ignition, the engine can determine the optimal moment to fire the spark plug. This precise control allows for maximum energy extraction from the engine, resulting in improved power output and efficiency.

**Application to Rotary Engines**

The Skyactiv engine's principles can be applied to rotary engines, particularly when it comes to optimizing combustion and air-fuel ratios. By incorporating a supercharger and utilizing advanced ignition timing strategies, rotary engineers can unlock the full potential of these unique engines.

However, the specific application of Skyactiv technology to rotary engines is still in its infancy. As the automotive industry continues to evolve, we can expect to see more innovative approaches to engine design, including the integration of Skyactiv principles into existing technologies.

**Conclusion**

The Skyactiv engine represents a significant leap forward in engine technology, offering improved efficiency, power output, and reduced emissions. By understanding the unique features and components of this technology, engineers and enthusiasts can unlock new possibilities for high-performance engines.

Whether applied to piston cylinder engines or rotary engines, Skyactiv's principles offer a promising approach to optimizing combustion and air-fuel ratios. As we continue to explore the potential of this technology, it will be exciting to see how it evolves and impacts the automotive industry in the years to come.

**Links to Additional Resources**

For those interested in learning more about the Skyactiv engine and its applications, check out our following videos:

* "Skyactiv Engine: A Deep Dive into Its Technology"

* "Rotary Engines with Skyactiv: How It Works and Its Potential"

* "The Future of Engine Design: Skyactiv and Beyond"

These videos offer a comprehensive exploration of the Skyactiv engine, including its history, design principles, and potential applications. Whether you're an enthusiast or an engineer, we invite you to join us on this journey into the world of advanced engine technology.

"WEBVTTKind: captionsLanguage: enhello everyone and welcome in this video we are talking about efficient rotary engines generally two words that don't go together efficient and rotary because rotary engines are not efficient that's actually kind of why they died out along with bad emissions however it was reported by jalopnik that they interviewed mazda's vice president of research and development and he said that there was a possibility that in the future there could be a skyactiv-x rotary engine so in this video we're going to be looking at five different elements of the skyactiv-x internal combustion engine which is a piston cylinder engine and see how those five elements might be applied to a rotary engine now personally i think speculation is dumb i don't like doing it uh i don't like you know saying what could be in the future but i do think it's cool to look from a factual standpoint what elements of a skyactiv-x engine could actually be applied to this engine and what it actually works so that's what the plan is for this video to get into those five elements and talk about how you could improve this engine using skyactivex principles so the first element we're going to talk about is compression ratio and there's a direct correlation between compression ratio and efficiency the higher your compression ratio the more efficient your engine is and so with mazda's skyactivex engine and their prototype they are running a compression ratio of 16 to one very high now how can this be applied to a rotary engine and a rotary engine assuming you keep you maintain the shape of this rotor and you maintain the shape of this rotor housing is limited in compression ratio now it doesn't necessarily mean that you can't have high compression ratios the mazda rx-8 had a compression ratio of 10 to 1 which isn't all that low but you are limited by the shape and so here's why if you're looking at this housing here here's going to be your maximum volume for your intake and then you're going to compress that volume up against this wall right here so you have a very large volume right here you compress that down to a smaller volume right here now that ratio is going to determine what your compression ratio can be in addition to that on this rotor you have a little cavity and so that cavity increases the displacement of this engine and it determines what your compression ratio is going to be so the larger this cavity the more displacement you're going to have the lower that your compression ratio is going to be so if you were to fill this in fully well then you would increase your compression ratio because the volume here relative to here is going to be changed now i looked at some studies which looked at you know what's the maximum compression ratio possible and it is possible to get close to that 16 to 1 compression ratio that mazda has in their current piston cylinder skyactivex engine the downside is if you're filling in that cavity right there then you're going to be reducing your overall displacement of the engine so you could make it more efficient however you're going to need to increase the size of it overall if you want the same displacement now the second element of mazda's skyactivex engine and how it might perhaps be applied to this rotary engine is sp ccci so perhaps the most important element mazda's spark plug controlled compression ignition and this is how they're able to achieve such great efficiencies what they're doing is they're using a very lean mixture uh air fuel ratio within that combustion chamber in the piston cylinder so the majority of the air in there has a air fuel ratio of about 37 to one and then using a direct injector they inject in a little bit more fuel near the spark plug so that as that piston is coming up there's a slightly less lean area near the spark plug that's at about 29 to 1 air fuel ratio so the spark plug ignites that less lean area and then as combustion starts to occur it forces that leaner area around it to all combust from the pressure alone so could spcci be applied to a rotary engine and the first part of this question will be can we have direct injection with a rotary engine and yes we can we know that from looking at mazda's patent history we also know that they have done it in production using hydrogen as a fuel for rotary engines and having a direct injection of hydrogen into the intake portion of the engine and so then the second part is can we create those two different locations where you have different pockets of air fuel ratios so you could use port injection perhaps and that would give you you know a very lean air fuel mixture and then you could have a direct injector located near the spark plugs where you then inject a little bit more fuel and so as you have that compression you inject a little bit more fuel you have that richer air fuel pocket and then this spark ignites that richer air fuel pocket and then that causes the surrounding area to combust due to compression you could also do different methodologies where you have a direct injector over on this end get that to mix with the air as it's coming across and then have another injector over here which would then allow you to have those two different pockets of air fuel ratios now the third element is instant combustion and this goes hand in hand with spcci part of why spcci is so effective is from that compression ignition compression ignition happens very quickly all of your air fuel mixture igniting at virtually the same time as a result you create more power and you have better efficiency and so can you have that instant combustion with this engine well one of the differences uh with a rotary engine versus for example a piston cylinder engine is you often have these two spark plugs rather than just one and the reason why you have two spark plugs here you can see that combustion chamber is very long and so because it's very long if you were to just have one in the center it would take a long time for that flame to travel out that entire distance of that combustion chamber so mazda includes two spark plugs you have two ignition sources and the flame doesn't have to travel quite as far because you have those two locations where the flame is starting from now if you were to use compression ignition perhaps you could just use a single spark plug because by having that single spark plug creating a less lean air fuel mixture next to it then you could rely on compression ignition so the pressure of that surrounding area has increased and then it ignites all of it simultaneously very quick combustion from using that spcci method and as a result having better efficiency and better power now as the engine gets into higher engine speeds and higher engine loads where you start reducing that air fuel ratio and you're going for specifically making power mazda in their skyactiv engines currently allows you to just use a spark ignition engine so it runs on the traditional auto cycle it doesn't run sp ccci when you're at high load and high engine rpm so as a result you know with the rotary engine it'd be likely that they would maintain those two spark plugs to allow for that high power mode when spcci is a bit more difficult to achieve so when you get up into the higher engine rpm and higher engine loads you would run purely you know using a traditional auto cycle so intake compression power exhaust not relying on compression to ignite it rather using your two spark plugs to ignite it and have that flame travel out the fourth element of the skyactivex engine we're going to apply to this is the supercharger and so the sky activex engine needs a ton of air in order to achieve those really high air fuel ratios and so if you still want to maintain power you need to be able to inject a good amount of fuel but if you inject a lot of fuel and you want a very high air fuel ratio that means you need a ton of air that's why mazda has the supercharger on the sky activex currently and so the same thing could be applied to this and the benefit of adding all that air and having that lean combustion is that you reduce the overall temperatures of combustion so by reducing combustion temperatures what you're doing is you're reducing the likelihood that you're going to have nitrogen oxide emissions so you're improving emissions and you're also improving efficiency because by forcing more air into that engine you have more air that's going to expand once combustion occurs and so you're going to get more useful energy out of that air expanding during that combustion stroke now the fifth and final element of the skyactivex engine which we're going to talk about how it could be applied to this rotary engine is using a pressure sensor and using a pressure sensor within the piston cylinder skyactivex engine is critical for optimizing its performance and so in that piston cylinder engine you have that pressure sensor at the top of the cylinder so as you ignite that less lean area that area of a slightly richer air fuel mixture near the spark plug then you start to have an increase in pressure and then from that pressure increase the rest of that surrounding area compression ignites so you have that compression ignition now when that compression ignition occurs you see a spike in pressure and so you want to optimize the timing of when that spark plug fires so that you get the maximum amount of useful work by monitoring when that pressure sensor sees that spike so for example here looking at the rotary engine you've got your spark plug here you've got your pressure sensor over here as you start to compress that air and fuel mixture your spark plug fires you start to see as that flame starts propagating out a slight rise in the pressure and then you see a spike as compression ignition occurs and the rest of that air fuel mixture in the surrounding area at a leaner air fuel mixture ignites so you want that to occur at the optimal time so you get the maximum amount of pressure pushing against this rotor and getting the maximum amount of useful work out of the engine and the way that you do that is by monitoring when did you fire that spark plug and when did peak pressure occur so then you know where that peak pressure is going to be on this rotor and then you can optimize that ignition timing when the spark plug fires to make sure that that peak pressure occurs at the exact moment you want it to now i will include some links to rotary and other skyactivex engine videos which i have created if you're interested in checking those out if you have any questions or comments of course feel free to leave those below thanks for watchinghello everyone and welcome in this video we are talking about efficient rotary engines generally two words that don't go together efficient and rotary because rotary engines are not efficient that's actually kind of why they died out along with bad emissions however it was reported by jalopnik that they interviewed mazda's vice president of research and development and he said that there was a possibility that in the future there could be a skyactiv-x rotary engine so in this video we're going to be looking at five different elements of the skyactiv-x internal combustion engine which is a piston cylinder engine and see how those five elements might be applied to a rotary engine now personally i think speculation is dumb i don't like doing it uh i don't like you know saying what could be in the future but i do think it's cool to look from a factual standpoint what elements of a skyactiv-x engine could actually be applied to this engine and what it actually works so that's what the plan is for this video to get into those five elements and talk about how you could improve this engine using skyactivex principles so the first element we're going to talk about is compression ratio and there's a direct correlation between compression ratio and efficiency the higher your compression ratio the more efficient your engine is and so with mazda's skyactivex engine and their prototype they are running a compression ratio of 16 to one very high now how can this be applied to a rotary engine and a rotary engine assuming you keep you maintain the shape of this rotor and you maintain the shape of this rotor housing is limited in compression ratio now it doesn't necessarily mean that you can't have high compression ratios the mazda rx-8 had a compression ratio of 10 to 1 which isn't all that low but you are limited by the shape and so here's why if you're looking at this housing here here's going to be your maximum volume for your intake and then you're going to compress that volume up against this wall right here so you have a very large volume right here you compress that down to a smaller volume right here now that ratio is going to determine what your compression ratio can be in addition to that on this rotor you have a little cavity and so that cavity increases the displacement of this engine and it determines what your compression ratio is going to be so the larger this cavity the more displacement you're going to have the lower that your compression ratio is going to be so if you were to fill this in fully well then you would increase your compression ratio because the volume here relative to here is going to be changed now i looked at some studies which looked at you know what's the maximum compression ratio possible and it is possible to get close to that 16 to 1 compression ratio that mazda has in their current piston cylinder skyactivex engine the downside is if you're filling in that cavity right there then you're going to be reducing your overall displacement of the engine so you could make it more efficient however you're going to need to increase the size of it overall if you want the same displacement now the second element of mazda's skyactivex engine and how it might perhaps be applied to this rotary engine is sp ccci so perhaps the most important element mazda's spark plug controlled compression ignition and this is how they're able to achieve such great efficiencies what they're doing is they're using a very lean mixture uh air fuel ratio within that combustion chamber in the piston cylinder so the majority of the air in there has a air fuel ratio of about 37 to one and then using a direct injector they inject in a little bit more fuel near the spark plug so that as that piston is coming up there's a slightly less lean area near the spark plug that's at about 29 to 1 air fuel ratio so the spark plug ignites that less lean area and then as combustion starts to occur it forces that leaner area around it to all combust from the pressure alone so could spcci be applied to a rotary engine and the first part of this question will be can we have direct injection with a rotary engine and yes we can we know that from looking at mazda's patent history we also know that they have done it in production using hydrogen as a fuel for rotary engines and having a direct injection of hydrogen into the intake portion of the engine and so then the second part is can we create those two different locations where you have different pockets of air fuel ratios so you could use port injection perhaps and that would give you you know a very lean air fuel mixture and then you could have a direct injector located near the spark plugs where you then inject a little bit more fuel and so as you have that compression you inject a little bit more fuel you have that richer air fuel pocket and then this spark ignites that richer air fuel pocket and then that causes the surrounding area to combust due to compression you could also do different methodologies where you have a direct injector over on this end get that to mix with the air as it's coming across and then have another injector over here which would then allow you to have those two different pockets of air fuel ratios now the third element is instant combustion and this goes hand in hand with spcci part of why spcci is so effective is from that compression ignition compression ignition happens very quickly all of your air fuel mixture igniting at virtually the same time as a result you create more power and you have better efficiency and so can you have that instant combustion with this engine well one of the differences uh with a rotary engine versus for example a piston cylinder engine is you often have these two spark plugs rather than just one and the reason why you have two spark plugs here you can see that combustion chamber is very long and so because it's very long if you were to just have one in the center it would take a long time for that flame to travel out that entire distance of that combustion chamber so mazda includes two spark plugs you have two ignition sources and the flame doesn't have to travel quite as far because you have those two locations where the flame is starting from now if you were to use compression ignition perhaps you could just use a single spark plug because by having that single spark plug creating a less lean air fuel mixture next to it then you could rely on compression ignition so the pressure of that surrounding area has increased and then it ignites all of it simultaneously very quick combustion from using that spcci method and as a result having better efficiency and better power now as the engine gets into higher engine speeds and higher engine loads where you start reducing that air fuel ratio and you're going for specifically making power mazda in their skyactiv engines currently allows you to just use a spark ignition engine so it runs on the traditional auto cycle it doesn't run sp ccci when you're at high load and high engine rpm so as a result you know with the rotary engine it'd be likely that they would maintain those two spark plugs to allow for that high power mode when spcci is a bit more difficult to achieve so when you get up into the higher engine rpm and higher engine loads you would run purely you know using a traditional auto cycle so intake compression power exhaust not relying on compression to ignite it rather using your two spark plugs to ignite it and have that flame travel out the fourth element of the skyactivex engine we're going to apply to this is the supercharger and so the sky activex engine needs a ton of air in order to achieve those really high air fuel ratios and so if you still want to maintain power you need to be able to inject a good amount of fuel but if you inject a lot of fuel and you want a very high air fuel ratio that means you need a ton of air that's why mazda has the supercharger on the sky activex currently and so the same thing could be applied to this and the benefit of adding all that air and having that lean combustion is that you reduce the overall temperatures of combustion so by reducing combustion temperatures what you're doing is you're reducing the likelihood that you're going to have nitrogen oxide emissions so you're improving emissions and you're also improving efficiency because by forcing more air into that engine you have more air that's going to expand once combustion occurs and so you're going to get more useful energy out of that air expanding during that combustion stroke now the fifth and final element of the skyactivex engine which we're going to talk about how it could be applied to this rotary engine is using a pressure sensor and using a pressure sensor within the piston cylinder skyactivex engine is critical for optimizing its performance and so in that piston cylinder engine you have that pressure sensor at the top of the cylinder so as you ignite that less lean area that area of a slightly richer air fuel mixture near the spark plug then you start to have an increase in pressure and then from that pressure increase the rest of that surrounding area compression ignites so you have that compression ignition now when that compression ignition occurs you see a spike in pressure and so you want to optimize the timing of when that spark plug fires so that you get the maximum amount of useful work by monitoring when that pressure sensor sees that spike so for example here looking at the rotary engine you've got your spark plug here you've got your pressure sensor over here as you start to compress that air and fuel mixture your spark plug fires you start to see as that flame starts propagating out a slight rise in the pressure and then you see a spike as compression ignition occurs and the rest of that air fuel mixture in the surrounding area at a leaner air fuel mixture ignites so you want that to occur at the optimal time so you get the maximum amount of pressure pushing against this rotor and getting the maximum amount of useful work out of the engine and the way that you do that is by monitoring when did you fire that spark plug and when did peak pressure occur so then you know where that peak pressure is going to be on this rotor and then you can optimize that ignition timing when the spark plug fires to make sure that that peak pressure occurs at the exact moment you want it to now i will include some links to rotary and other skyactivex engine videos which i have created if you're interested in checking those out if you have any questions or comments of course feel free to leave those below thanks for watching\n"