Duke Engines

[TigerRaptor]

I really would like to see this engine more in action. With car companies moving more towards fuel economy cars with smaller engines, and whiny CVT transmissions. This engine could change things for the better.

[youtube]c19kn3drdFU[/youtube]

[Krom]

Cool to see creative ideas for engines still showing up. Although it may only end up being a stop gap on the path towards pure electric if they ever figure out a battery technology that can match the range and refueling convenience of traditional internal combustion engines.

Also I've driven 4 vehicles with CVTs including my own and none of them have that transmission whine. It has probably been pretty much fixed, because IIRC the 2007-2009 Nissan vehicles were pretty notorious.

[TigerRaptor]

Time will tell.

My co-work has a Lancer with a CVT transmission that whines. Of course being a smart ass, I'm like just pretend you have supercharger. I still like to poke fun at CVT's every now and then. Once in a while I'll hear someone complaining about a whining noise, but not nearly as often. To be fair CVT's do give the vehicle a nice ride. Also greatly improves fuel economy along with other benefits. Call me old fashion. I like still the feel of a automation transmission. Especially when driving with a Magnaflow cat-back dual exhaust system.

[Tunnelcat]

I've got a CVT in my Subaru and it doesn't whine. It sounds just like any other automatic transmission. It also has steering wheel paddle shifters for those drivers who desire to actually shift the transmission.

I think Krom is right. Once we develop a battery technology that gets beyond the 300 mile range and charges fast, the internal combustion engine is going to disappear. It's either that or fuel cell technology that takes over.

[sigma]

Oh, not know, everyone decides for himself. I had more than 25 different cars with different engines. Now I ride mostly on a four-wheel drive Kia Sorento with an automatic transmission, but the most confident I feel on cars with manual gearbox and a simple atmospheric engine, because if it breaks down, in most cases, I can repair it yourself on the road.
Especially it is important in the forests, floodplains unfamiliar rivers and lakes and just deserted places where I like to ride sometimes, and especially in the Russian climatic conditions and often with little hope for help from other people, not to mention the car service station

[Krom]

I'll just add that I really like my CVT, it just makes the ride so much smoother in every way. Every time I go to Costa Rica I'm reminded of how nice a CVT is because down there it is all mountains and the SUV we drive is always hunting for gears. (Although a lot of that is because it is a heavy SUV on a dinky 4 cylinder engine with a 3 speed transmission.)

I do have my doubts a CVT is as durable as a conventional gearbox, which is why I drive my car pretty gently. I wouldn't want to haul a 5 ton trailer any length or climb up and down mountains in Costa Rica every day on it for instance. It wouldn't surprise me if the people complaining about CVTs are the type who drive so aggressively it would run any vehicle into the ground, and the CVTs just happen to go first since it is a less mature technology.

[Tunnelcat]

The CVT in my Subaru has one little irritating quirk. When you shift from reverse to forward, it takes several seconds to occur. Just enough time for someone to get ticked off waiting for you to start driving away after backing out of your driveway. It is probably programmed in to protect the system from damage, so I'll live with it. Other than that, I haven't noticed much difference between it and the automatic in my other car. In fact, it's downright creepy the way it maintains the optimal acceleration and engine speed. The gas mileage is fantastic too.

[Tunnelcat]

Oh, not know, everyone decides for himself. I had more than 25 different cars with different engines. Now I ride mostly on a four-wheel drive Kia Sorento with an automatic transmission, but the most confident I feel on cars with manual gearbox and a simple atmospheric engine, because if it breaks down, in most cases, I can repair it yourself on the road.
Especially it is important in the forests, floodplains unfamiliar rivers and lakes and just deserted places where I like to ride sometimes, and especially in the Russian climatic conditions and often with little hope for help from other people, not to mention the car service station

Yeah, a manual is far more robust for driving around in deserted places and for 4 wheeling in the wilderness. Manual transmissions are bullet proof without all those hydraulics and computers. But once you get to be old, pushing in a clutch gets tiring in city driving.

[sigma]

I think in old age for me will more comfortable to be a passenger than a driver... Although who knows, stranger things have happened-perhaps the old man may will want to remember his youth!

[Tunnelcat]

That's the problem with old age. Sometimes you just aren't physically able to relive your youth. When the day comes I can't drive my own car, I'll be ready to pack it in for good because that means I'm either blind or physically unable to drive, so why bother to keep going if I can't do things for myself. I'm too independent.

[woodchip]

Well I'm in my late 60's and I drive a 6 speed manual Dodge Ram pick up. Had it for 8 years now and it is getting a bit more difficult to climb up into the cab. As an aside, after 130k miles, I still have the same Michlen tires on it and tread still not to wear bars. Don't let getting older stop what you want to drive.

[Tunnelcat]

I'll drive until I can't see over the dashboard.

[sigma]

TC, believe it or not, but I started to learn to drive a car when I could barely see over the dashboard. And while I was sitting on a large pillow, which was placed in the driver's seat Jesus, I think I could write a book about my adventures related to cars..

[Tunnelcat]

First you're short, then you're tall, then you shrink.

[sigma]

Now almost all cars have a vertical adjustment of the driver's seat. It was not there before.

[Tunnelcat]

My driver's seat is cranked ALL the way up. I used to be 5' 3", but now I'm 5' 2½" and shrinking as I get older. The dashboard is getting higher and I can't lower that.

[Top Gun]

You need to do the granny thing and start piling cushions on the seat.

[snoopy]

I wonder what kind of efficiency and reliability they can get out of the design... the skeptic in me says there has to be a drawback of some type, or it would have already been done.

FWIW I think Tesla's barking up the right tree, I just don't know if all of the technology is quite ready for mass market yet. Powering your car using the grid = mass power production in efficiencies that you can't hope for in a vehicle-sized package. It does make me curious... I wonder if end to end efficiency of electric cars is really as efficient as traditional reciprocating engine vehicles? (By end to end I mean overall efficiency when you consider the whole energy chain from the power generation source to the wheels.)

[Spidey]

Heh, the answer that all depends on which side of the issue you are on.

We had a long debate on that very thing, and all I was provided with for “proof” were documents created by people invested in electric cars.

It’s a really complicated equation, and nobody without an agenda want’s to invest in figuring it out.

[Ferno]

I've been watching battery technology for a while now (I have to, seeing as I use them to fly), and there are three competing formulas now. LiMnCo2 cylindrical cells, LiHV, and Li-Graphene. The first has the safety, the second has the energy density and the third has the power density.

[Krom]

Considering conventional engines are somewhere around 30% efficient, beating it with an electric motor that can approach 95% efficiency is not particularly difficult. Even the current generation electric cars are easily double as efficient as gasoline vehicles when you factor in the well to wheels efficiency. (In tank/battery to wheels, electric vehicles are pushing 4x the efficiency of gasoline vehicles.) But all that efficiency doesn't do much good when the amount of energy you can carry with the vehicle is severely limited.

The big problem with gasoline vehicles is energy loss, where as the big problem with electric vehicles is energy capacity. Gasoline powered vehicles make up for their terrible efficiency by carrying a gargantuan amount of energy (in the form of fuel) with them, by comparison a battery doesn't even come close to being able to store that much energy per mass. Pretty much every other aspect of electric vehicles is ready to go and could easily replace gasoline vehicles, it is just the battery holding it up.

[TigerRaptor]

I wonder what kind of efficiency and reliability they can get out of the design... the skeptic in me says there has to be a drawback of some type, or it would have already been done.

FWIW I think Tesla's barking up the right tree, I just don't know if all of the technology is quite ready for mass market yet. Powering your car using the grid = mass power production in efficiencies that you can't hope for in a vehicle-sized package. It does make me curious... I wonder if end to end efficiency of electric cars is really as efficient as traditional reciprocating engine vehicles? (By end to end I mean overall efficiency when you consider the whole energy chain from the power generation source to the wheels.)

It's 2016 and this video was made 3 years ago. I scoured the internet for more information, nothing new. If there is a drawback and this is just a wild guess. I wounder if they ran into the same issue like Mazda rotary engine. Oil getting into the combustion chamber.

[Tunnelcat]

It's 2016 and this video was made 3 years ago. I scoured the internet for more information, nothing new. If there is a drawback and this is just a wild guess. I wounder if they ran into the same issue like Mazda rotary engine. Oil getting into the combustion chamber.

I don't think oil getting into the combustion chamber is any more of a problem than with any regular piston engine. The Duke Engine still has regular pistons, with conventional sealing rings, so they should work the same way. I'm guessing that this engine may end up in motorcycle, aircraft or in marine applications before it ends up in a car. It's compact size, simple construction and low vibration characteristics would be great. What I do wonder about is what kind of stresses are put on that reciprocator mechanism? All the piston power goes through that one large part and I wonder what kind of offset thrust is being generated in that main bearing.

http://thekneeslider.com/duke-engines-5 ... al-engine/

A 2 year old interview with a Duke engineer.

https://rideapart.com/articles/duke-engines-interview

[Sergeant Thorne]

That engine strikes me as being a physically troublesome (inefficient?) design, with the potential for a lot of bad stress acting on parts that are apparently beefed up/designed to handle it. The low-RPM nature of it is pretty cool, though.

[Tunnelcat]

A large marine application perhaps.

[woodchip]

Or tractors, heavy equipment. Does the Duke do diesel?

[Lothar]

The big problem with gasoline vehicles is energy loss, where as the big problem with electric vehicles is energy capacity

I recently started driving a 2013 Chevy Volt. Seems like a solid interim solution to the problem -- it's an all-electric drivetrain with a gas generator to supplement the battery. Range is about 38 miles on battery alone, and about 320 with a full tank of gas as well.

The last time I filled the tank was in December, about 250 miles away from here in Wyoming. Used up most of that gasoline to get home, and have been on electric for all but about 10 miles since then.

[Tunnelcat]

Hey Lothar. How's the fit and finish with your car? Any problems crop up yet?

[Lothar]

I got it off-lease with about 18,000 miles on it. Thus far I'm really happy with it. It's a little dirty because I park outside in the snow and stuff.

[snoopy]

A large marine application perhaps.

I don't particularly see it... once you get larger than your typical outboard, you get into diesels that already have the higher compression ratios and the benefit of high maturity.

Krom, on your numbers: I'm not sure...

Sure, your gasoline engine maybe makes it to 40% efficiency, and let's say you manage 30-35% efficiency to the wheels.

For an electric car, if you want to consider the generation chain: The power plant might run at 60% efficiency, assume 94% delivery efficiency

(from here)

Then, you have to convert AC to DC to deliver to the car - at let's say 90%; you have to deliver the regulated power to the wheels when you want to go... again at 85-90% efficiency, and finally your motors drive approaching 95% efficiency.. but only at optimum speed - so for typical driving you're probably looking at something more like 85-90% (maybe). That puts me at 41% fuel to wheels efficiency using the best numbers... which is better than your gas engine, but not head and shoulders better.

(Note: that assumes a fuel-based energy generation with a steam turbine... obviously wind/water/etc generation comes "for free" in that the environment does the conversion from fuel to a form of stored energy. - but you're still facing an efficiency question converting that stored energy to electricity.)

[Krom]

I looked up a couple studies when I posted that, you are pitting the well to wheels efficiency of the electric against the strict engine efficiency of the gasoline vehicle. In well to wheels on a gasoline engine if you take into account obtaining the fuel, refining it, transporting it, and every other step then the typical gasoline engine is doing pretty good when it breaks 15% efficiency.

[snoopy]

I looked up a couple studies when I posted that, you are pitting the well to wheels efficiency of the electric against the strict engine efficiency of the gasoline vehicle. In well to wheels on a gasoline engine if you take into account obtaining the fuel, refining it, transporting it, and every other step then the typical gasoline engine is doing pretty good when it breaks 15% efficiency.

Actually, I was putting fuel to wheels efficiency of both head to head... power generation also has its own mining/transportation/refinement chain, too. I believe you that going from oil in the ground to unleaded gasoline is probably less efficient than (say) going from coal in the ground to the furnace - but my overall point stands: the traditional way of looking at electric vehicles ignores half of the energy chain to come up with the notion that it's awesomely more efficient.

[Sergeant Thorne]

Next you'll be telling us that solar and wind energy aren't viable alternatives to coal or nuclear power...

[Krom]

https://matter2energy.wordpress.com/201 ... fficiency/
http://www.johnsavesenergy.com/WellToWheels.html