Efficient Engines

[Wu Wei]

Gasoline? Diesel? Surely they are the past, not the future.

We live in the present, not the future.
Until we get anti-matter drive systems,
we're stuck with what works now.

I have said many times in such discussions.... as long as things like this exist, and are being used extensively.

there will be gas and diesel engines. So why not find a more efficient and less polluting gas an diesel engine

 

[Revoltingest]

True but, unlike the Wankel, this is all known technology. OP engines are well-known, and my humble VW has both a supercharger and a turbo on it, giving a 1.4 l engine the power of a 2l one, with much greater part-throttle fuel economy.

Added bonus of this engine is no throttling losses
typical of spark ignited gasoline engines.
Also it can idle using less fuel. Conventional engines
need a minimum of gasoline to ensure that the fuel
& air mixture is within the flammability range.
Compression ignition can happen at any low ratio.

 

[Wu Wei]

It's a prototype, Booboo.
The Wankel was known from the outset to be inherently
fuel inefficient due to high surface to volume ratio of the
combustion chamber. But it had a niche where high
power to weight ratio was important & fuel economy wasn't.

I know it is a prototype ya fetid Scot, that is why I said it would be interesting to see if it i used in production. Also, what will the ultimate cost be for this, and a cheapskate like you should be thinking that too. It can be the most efficient thing we have ever seen in a fuel powered engine. But if it ups the cost of a truck by $10,000 (example so don't get yer undies in.a bunch) will it ever be used.

And the Wankel, on paper was suppose t be great, the reality was a bit different. Admittedly this engine makes since due to the high compression combustion system, but one must also consider its durability. how long will it run without issue. Diesel engines are not known to be weak, they are also known to be pretty beefy, but make them smaller, to save on weight, with this design, how long will it run. I am hoping long, it looks good, but it is not in production

 

[Revoltingest]

I have said many times in such discussions.... as long as things like this exist, and are being used extensively.

there will be gas and diesel engines. So why not find a more efficient and less polluting gas an diesel engine

There are less polluting engines, eg, Stirling cycle, which uses
external combustion. But every application is a compromise of
competing goals, some of which are....
- Size
- Noise
- Weight
- Durability
- Reliability
- Emissions
- Cost to buy
- Fuel economy
- Cost to operate

 

[Wu Wei]

Added bonus of this engine is no throttling losses
typical of spark ignited gasoline engines.
Also it can idle using less fuel. Conventional engines
need a minimum of gasoline to ensure that the fuel
& air mixture is within the flammability range.
Compression ignition can happen at any low ratio.

They also tend to have greater emissions. But they claim the high temps take care of that.

 

[Wu Wei]

There are less polluting engines, eg, Stirling cycle, which uses
external combustion. But every application is a compromise of
competing goals, some of which are....
- Size
- Noise
- Weight
- Durability
- Reliability
- Emissions
- Cost to buy
- Fuel economy
- Cost to operate

that's my point

 

[Revoltingest]

I know it is a prototype ya fetid Scot, that is why I said it would be interesting to see if it i used in production. Also, what will the ultimate cost be for this, and a cheapskate like you should be thinking that too. It can be the most efficient thing we have ever seen in a fuel powered engine. But if it ups the cost of a truck by $10,000 (example so don't get yer undies in.a bunch) will it ever be used.

There is no risk of me having bunched up undies.
Anyway, it's around a $10K option to upgrade a pickup truck
from gasoline to diesel. Not worth it for me, given the few
miles I put on per year (well under 10K miles per year).

And the Wankel, on paper was suppose t be great, the reality was a bit different.

On paper, it was clear that fuel economy would be poor
because of the shape of the combustion chamber. This
was known to all. Also, sealing was a very difficult problem,
much more so than piston rings in a cylinder.

Btw, I have a Dake steam engine, which uses a rectangular
piston. They're not efficient, but they're simple & compact,
so good for intermittent power, eg, cranes, steering.

Admittedly this engine makes since due to the high compression combustion system, but one must also consider its durability. how long will it run without issue. Diesel engines are not known to be weak, they are also known to be pretty beefy, but make them smaller, to save on weight, with this design, how long will it run. I am hoping long, it looks good, but it is not in production

Bear (haha) in mind that at a given RPM, piston speed is
about half of a conventional engine. And there is no valve
train or cylinder head. So there are those advantages.

 

[Wu Wei]

True but, unlike the Wankel, this is all known technology. OP engines are well-known, and my humble VW has both a supercharger and a turbo on it, giving a 1.4 l engine the power of a 2l one, with much greater part-throttle fuel economy.

It will be getting the details right, like the emissions, that may bedevil a new design like this. Diesel particulates? NOx? The rules are tightening all the time.

But that was air cooled using a spark plug. and the compresion was on the opposite sides, not in th middle. BMW has the same thing, basically, on their motorcycles, and that is a great engine. But this is taking that concept and turning it around, as well as using 2 crankshafts as opposed to the one you find in the VW and BMW.

Don't get me wrong, I like the concept and it makes sense. I also hope it works, but time will tell

 

[Brickjectivity]

Added bonus of this engine is no throttling losses
typical of spark ignited gasoline engines.
Also it can idle using less fuel. Conventional engines
need a minimum of gasoline to ensure that the fuel
& air mixture is within the flammability range.
Compression ignition can happen at any low ratio.

I like its balance. They catch that bit of power that is often lost to shaking the engine and the vehicle. You can visibly see trucks shake from the engines. All that shaking is lost power.

So I guess this truck engine is a potential competitor with electrics should they become more viable? Its one thing to see a prototype and another to see a new truck in the dealerships.

 

[Revoltingest]

They also tend to have greater emissions. But they claim the high temps take care of that.

It isn't that emissions are "greater" (whatever that means).
Rather, the problem of meeting regulatory requirements
is different. And as the guy said, higher exhaust temps
improve catalyst efficiency.

Btw, high exhaust temps might mean an opportunity to
extract more energy, eg, a small Stirling Cycle engine
running a generator. This could be practical for busses,
locomotives, & other high capital cost larger applications.

 

[Revoltingest]

that's my point

Are we agreeing?
I might have to re-think what I'm posting.

 

[Wu Wei]

On paper, it was clear that fuel economy would be poor
because of the shape of the combustion chamber. This
was known to all. Also, sealing was a very difficult problem,
much more so than piston rings in a cylinder.

Btw, I have a Dake steam engine, which uses a rectangular
piston. They're not efficient, but they're simple & compact,
so good for intermittent power, eg, cranes, steering.
.

Yeah, well, that is not what I remember from whn I was a kid...oh wait...your older tham me....and an....(eeeeew) engineer...you probably saw the tech specs....geezer.

There were allegedly multiple advantages to the Wankel, not fuel. and the one car I was in that had one wa incredibly powerful and fast, but it had major disadvantages, from the mechanical standpoint, tolerances being one of those.

Bear (haha) in mind that at a given RPM, piston speed is
about half of a conventional engine. And there is no valve
train or cylinder head. So there are those advantages.

True, but you would need two crankshafts and the systems to drive them

 

[Revoltingest]

I like its balance. They catch that bit of power that is often lost to shaking the engine and the vehicle. You can visibly see trucks shake from the engines. All that shaking is lost power.

So I guess this truck engine is a potential competitor with electrics should they become more viable? Its one thing to see a prototype and another to see a new truck in the dealerships.

Engines & electrics are indeed in competition, but also
cooperation, ie, the hybrid drive.
Alas, I think seeing a production vehicle with this engine
is a ways off. A whole lot of development work to do.

 

[exchemist]

Added bonus of this engine is no throttling losses
as with a typical spark ignited gasoline engine.

Yeah well,

I have said many times in such discussions.... as long as things like this exist, and are being used extensively.

there will be gas and diesel engines. So why not find a more efficient and less polluting gas an diesel engine

I think you are quite wrong about that.

Though conceivably we may find hydrogen-fuelled IC engines continue to have some applications.

The IC engine is already close to its thermodynamic limit, so I don't hold out much hope of significantly improved efficiency. Basically you need to get away from little mobile heat engines if you want to improve much further.

 

[Revoltingest]

Yeah, well, that is not what I remember from whn I was a kid...oh wait...your older tham me....and an....(eeeeew) engineer...you probably saw the tech specs....geezer.

I remember Ford experimenting with Wankel, turbine,
scotch yoke, & Stirling engines back in the 70s.

There were allegedly multiple advantages to the Wankel, not fuel. and the one car I was in that had one wa incredibly powerful and fast, but it had major disadvantages, from the mechanical standpoint, tolerances being one of those.



True, but you would need two crankshafts and the systems to drive them

The extra crankshaft is mechanically simpler & more reliable
than a valve train. And cylinder heads have given me more
trouble than crankshafts.

Btw, valve trains do eat horsepower, which is why desmodromic
actuation was popular (eg, Ducati). It eliminated heavy valve
springs necessary for high speed operation.

 

[Wu Wei]

It isn't that emissions are "greater" (whatever that means).
Rather, the problem of meeting regulatory requirements
is different. And as the guy said, higher exhaust temps
improve catalyst efficiency.

Btw, high exhaust temps might mean an opportunity to
extract more energy, eg, a small Stirling Cycle engine
running a generator. This could be practical for busses,
locomotives, & other high capital cost larger applications.

Slow down bunky, get out of engineering mode and think mechanic mode

emissions - the production and discharge of something, especially gas or radiation.

in other words what the higher exhaust temps to to catalytic efficiency...as it applies to what comes out as exhaust to meet the regulatory requirements

Higher exhaust temps also mean your exhaust system can last longer too...whoopie doopie

It is what it takes to get those temps and that effect on the engine over time.

 

[Wu Wei]

I remember Ford experimenting with Wankel, turbine,
scotch yoke, & Stirling engines back in the 70s.

The extra crankshaft is mechanically simpler & more reliable
than a valve train. And cylinder heads have given me more
trouble than crankshafts.

Btw, valve trains do eat horsepower, which is why desmodromic
actuation was popular (eg, Ducati). It eliminated heavy valve
springs necessary for high speed operation.

Anything that moves in an engine, or anything that engine moves, eat horsepower HP vs BHP

 

[Wu Wei]

Yeah well,

I think you are quite wrong about that.

Though conceivably we may find hydrogen-fuelled IC engines continue to have some applications.

The IC engine is already close to its thermodynamic limit, so I don't hold out much hope of significantly improved efficiency. Basically you need to get away from little mobile heat engines if you want to improve much further.

Then let me say as long as those applications exist, I do not think the gas/diesel engines will be going away anytime soon...beyond that I think we can agree to disagree

 

[Revoltingest]

The IC engine is already close to its thermodynamic limit...

This is true for engines like those powering large ships
(gigantic low speed diesels which are designed for max
fuel & operating economy with no real limits on cost, size,
& weight), but not so for small engines in cars.

Now this is a fuel efficient engine....

 

[Revoltingest]

Anything that moves in an engine, or anything that engine moves, eat horsepower HP vs BHP

There are differences though. The extra crankshaft will eat power.
But that's more than offset by the eliminated valve train, eliminated
throttling losses, uniflow savings, & halved piston speed.

Ultimately, it all comes down to how fuel stingy a design is when
it's put into production. Then everything is taken into account.