While techinically not a diesel engine, it is reported to be capable of burning diesel. Or more precisely, described as being "very fuel tolerant". And clearly, one glance at the pic reveals it's diesel heritage. Interesting conversion from the conventional Yanclone pushrod to the belt-driven OHC. The "self-supercharging" part is intriguing, if it's for real!!! Haven't invested my life savings just as yet. Any one there in the UK encountered this thing?
http://www.drivespark.com/four-wheelers ... 06754.html
Self-supercharged Engine
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pietenpol2002
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Self-supercharged Engine
Re: supercharging. Not sure it's quite the same thing but several car companies here are experimenting with 48v super capacitors powering superchargers. They can half engine capacity with the instant supercharger boost totally eliminating turbo lag.
Example: http://youtu.be/X9vZLYMoTCQ
Example: http://youtu.be/X9vZLYMoTCQ
Stuart. M1030M1, Honda NC700S, Grom!, Toyota Corolla 1.4 Turbo Diesel. Favouring MPG over MPH.
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gilburton
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Re: Self-supercharged Engine
Could it be using a top hat piston similar to the Bernard Hooper design? or possibly using a modified 2 stroke principal??
The Bernard Hooper design was also an "all fuels" tolerant engine.
http://users.breathe.com/prhooper/opads.htm
The Bernard Hooper design was also an "all fuels" tolerant engine.
http://users.breathe.com/prhooper/opads.htm
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Blunt Eversmoke
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Re: Self-supercharged Engine
The article actually contains not one but two intriguing questions.
The first: This engine "is based on a Yamaha racing diesel engine." Where to read up on that?
The second is, obviously, regarding the nature of the self-charging principle utilizing "gas inside the engine".
I am frequenting the experimental engines subforum of the Russian Experimental Aviation Association ressource where one engine scholar has linked to his article (obviously, in Russian, and pretty long at that, so I am not quoting it in full length here) describing an engine doing exactly that. If the two engines share any similarities, it could work as follows.
For this to work, the engine needs at least two combustion chambers separated from the cylinder space by poppet valves, rotary valves, you name it. They work alternately.
Assume the engine is started and running.
First chamber is open, the second one closed - in the second, constant-volume combustion is taking place.
On compression stroke, the first engine receives a fresh air charge compressed by the piston to a modest ratio of 8:1 to 12:1 or somesuch. At TDC, the second chamber opens and admits the hot, high-pressure combustion products to the cylinder space. These partly force the rest of fresh air from the cylinder space into the first combustion chamber, and, to a small degree, enter it themselves. Thus, the initial compression force of the fresh charge is equivalent to 22:1 or thereabout instead of the purely volumetric initial compression ratio - this further boosts efficiency, additionally to the ideal Otto constant-volume process.
The first combustion chamber is now closed and fuel is injected inside it and self-ignites. Constant-volume combustion takes place there.
Meanwhile, combustion products from the second chamber are free to work off their force on the piston.
Gas exchange follows, either per scavenging as in a two-stroke or with an exhaust and intake stroke as per four-stroke.
On compression stroke, fresh air charge is compressed into second combustion chamber,...etc..
Separating combustion space from cylinder space gives, in theory, following advantages:
Ideal Otto constant-volume combustion.
Pressure pikes are kept well away from piston, conrod and crank, so neither these nor the associated bearings are subjected to high forces.
Due to that, normal force pressing the piston against cylinder wall is also lower - which boost mechanical efficiency because of lower resulting friction
All of these components can also be made lighter than in a diesel - an advantage because now
More than one combustion chamber can be utilized, and thus the engine can spin up to gasser RPMs even on diesel fuel as the combustion now has not the itty bitty, teeny-weeny bit of time between compression and expansion strokes but all two strokes, if two-stroke, or four strokes, if four-stroke - or more if there is more than two combustion chambers per cylinder.
For starting, when no combustion products are available yet for "internal supercharging", self-ignition could be achieved by means known from other low-compression CI engines (early British diesel bikes or heavily tuned diesel trucks used for sled-pulling or pulling competitions come to mind), where ether, big glow-plugs or air-preheating is utilized.
This assumption of mine is supported by the rather bulky cylinder head of the "self-supercharged engine" - could it house the two combustion chambers and associated valves in addition to the standard valvetrain?
The first: This engine "is based on a Yamaha racing diesel engine." Where to read up on that?
The second is, obviously, regarding the nature of the self-charging principle utilizing "gas inside the engine".
I am frequenting the experimental engines subforum of the Russian Experimental Aviation Association ressource where one engine scholar has linked to his article (obviously, in Russian, and pretty long at that, so I am not quoting it in full length here) describing an engine doing exactly that. If the two engines share any similarities, it could work as follows.
For this to work, the engine needs at least two combustion chambers separated from the cylinder space by poppet valves, rotary valves, you name it. They work alternately.
Assume the engine is started and running.
First chamber is open, the second one closed - in the second, constant-volume combustion is taking place.
On compression stroke, the first engine receives a fresh air charge compressed by the piston to a modest ratio of 8:1 to 12:1 or somesuch. At TDC, the second chamber opens and admits the hot, high-pressure combustion products to the cylinder space. These partly force the rest of fresh air from the cylinder space into the first combustion chamber, and, to a small degree, enter it themselves. Thus, the initial compression force of the fresh charge is equivalent to 22:1 or thereabout instead of the purely volumetric initial compression ratio - this further boosts efficiency, additionally to the ideal Otto constant-volume process.
The first combustion chamber is now closed and fuel is injected inside it and self-ignites. Constant-volume combustion takes place there.
Meanwhile, combustion products from the second chamber are free to work off their force on the piston.
Gas exchange follows, either per scavenging as in a two-stroke or with an exhaust and intake stroke as per four-stroke.
On compression stroke, fresh air charge is compressed into second combustion chamber,...etc..
Separating combustion space from cylinder space gives, in theory, following advantages:
Ideal Otto constant-volume combustion.
Pressure pikes are kept well away from piston, conrod and crank, so neither these nor the associated bearings are subjected to high forces.
Due to that, normal force pressing the piston against cylinder wall is also lower - which boost mechanical efficiency because of lower resulting friction
All of these components can also be made lighter than in a diesel - an advantage because now
More than one combustion chamber can be utilized, and thus the engine can spin up to gasser RPMs even on diesel fuel as the combustion now has not the itty bitty, teeny-weeny bit of time between compression and expansion strokes but all two strokes, if two-stroke, or four strokes, if four-stroke - or more if there is more than two combustion chambers per cylinder.
For starting, when no combustion products are available yet for "internal supercharging", self-ignition could be achieved by means known from other low-compression CI engines (early British diesel bikes or heavily tuned diesel trucks used for sled-pulling or pulling competitions come to mind), where ether, big glow-plugs or air-preheating is utilized.
This assumption of mine is supported by the rather bulky cylinder head of the "self-supercharged engine" - could it house the two combustion chambers and associated valves in addition to the standard valvetrain?
Re: Self-supercharged Engine
Spotted this on the Autocar website...
http://www.autocar.co.uk/car-news/indus ... evelopment
Although heavily modified it is very clearly a Yanmar clone that apparently promises 20 percent power improvement along with economy benefits. Whilst the technology isn't described in any detail it has jut won Shell's "Low CO2" challenge prize (http://www.autocar.co.uk/car-news/indus ... tion-prize) and so must have come under some significant scrutiny. It won running on propane but will apparently run on most fuels.
Be interesting to see if this gets developed further. Whilst a 20% increase it, let's face it, still only 12hp when you started with a 10hp engine every small amount of power helps on bikes.
http://www.autocar.co.uk/car-news/indus ... evelopment
Although heavily modified it is very clearly a Yanmar clone that apparently promises 20 percent power improvement along with economy benefits. Whilst the technology isn't described in any detail it has jut won Shell's "Low CO2" challenge prize (http://www.autocar.co.uk/car-news/indus ... tion-prize) and so must have come under some significant scrutiny. It won running on propane but will apparently run on most fuels.
Be interesting to see if this gets developed further. Whilst a 20% increase it, let's face it, still only 12hp when you started with a 10hp engine every small amount of power helps on bikes.
1990 Honda NTV600 Revere