New internal combustion car sales to be banned in UK in 15 years

[humfrz]

Originally Posted by Tcoat

Here is a nice one nearby.

https://www.londonontariorealestate....ton-av-london/

Well, that's a nice looking property, but, I'll need a place that's a bit larger, for my friends to spread out in, when they play their country western music.




humfrz

[serialk11r]

Originally Posted by Tcoat

Far far less parts. No valving, lifting, camming, oiling, liquid cooling, charging, exhausting, vacuuming, fueling (well sort of fueling), all of which can break.

I've actually been looking into rotary engines again because of this. If you have a 250lb piston engine with lots of parts that cost money to assemble and replace producing 160hp...what's the point when a 250lb battery pack will be able to take your car 150 or even 200 miles?

Unlike Mazda's oil cooled rotors, there's 2 companies (AIEUK, and Freedom Motors) making Wankel engines that run a much hotter rotor with blowby gas and air cooling respectively. This means a loss of low end torque, but as you spin the engine faster that matters less, and now there's no oil pump needed. Apparently, apex seal issues have been solved too. Currently they run at slightly better efficiency than the Renesis, but if they bump the compression ratio up or turbocompound they should be able to touch car piston engines.

There's also a company called Liquidpiston making an inside-out Wankel, with an air cooled rotor. Their design squishes the air/fuel mix into a pocket for better combustion efficiency, but the cooling loss is still bad, and they may not have figured out the seals yet. Apparently their diesel engine hit 39% indicated thermal efficiency which isn't too bad, they are trying to hit 45% for military contracts.

Brings the total weight of a 1.3L 2 rotor engine producing over 200hp down to barely over 100 lbs including radiator, and now gasoline is in the running with electric again if you need light weight.

Doritos are the future of race cars and sports cars

[soundman98]

mazda's main claim for dropping the rotary was that it couldn't meet upcoming emissions standards..

i like the rotary as a motor just because it's unique, and would love a lawn mower or something with one, but have little desire for a car version.

[Dadhawk]

Originally Posted by serialk11r

Unlike Mazda's oil cooled rotors, there's 2 companies (AIEUK, and Freedom Motors) making Wankel engines that run a much hotter rotor with blowby gas and air cooling respectively.

Agh, Freedom Motors, brought to you by Dr. Moller the inventor of the SuperTrapp Muffler and the Moller "flying car" that has been two years from flying for 20 years now. (I so wanted to believe!)

Has Freedom Motors (an offshoot of the flying car engineering) produced an engine that is available in any products yet? I know they have claimed to be close any day now, but haven't seen anything in production.

[soundman98]

My understanding is that rotaries are great motors for constant rpm, medium loads. It makes them great for things like lawn mowers and backup generators, but poor at car propulsion where engine speed and overall load varies greatly.

[serialk11r]

Originally Posted by Dadhawk

Agh, Freedom Motors, brought to you by Dr. Moller the inventor of the SuperTrapp Muffler and the Moller "flying car" that has been two years from flying for 20 years now. (I so wanted to believe!)

Has Freedom Motors (an offshoot of the flying car engineering) produced an engine that is available in any products yet? I know they have claimed to be close any day now, but haven't seen anything in production.

I mean he put them on his own flying car, which did fly for a minute (that's a good sign LOL). On a side note, that guy doesn't have gray hair at age 84?? Is that even possible?

I read through a lot of his papers, I think the idea is pretty much that if you run the whole engine very hot, unburned fuel stops being a problem. Torque will suffer, but at high speed the volumetric efficiency will improve, and rotaries are stupid light to begin with so you can just use a bigger engine to get more power.

TBC on the rotor is nothing new, but to operate the trochoid housing at high temperature means you need a good dry high temperature lubricant (cermet, this is well researched by now), and insulator material underneath. I think he's claiming he can produce housings with cermet bonded to zirconia underneath to bring the entire combustion chamber surface temp up. The claimed BSFC numbers are good, equal to piston engines at WOT.

They claim to have a factory for assembly in India soon. If engines start materializing, it would be interesting to get one. Add an extra spark plug (drill hole, interference fit threaded aluminum tubes through the water jacket, braze the outside shut?), raise the compression ratio and run E40 fuel, it might be more fuel efficient than a piston engine used in a track-only car. Low rpm would probably still suck too much to make it a good street car engine, but I kind of want to try. You could easily pick up a 250hp engine, that's just wild.

I feel like Liquidpiston has a little better potential, but they seem to be even further away from being able to produce anything. The 70cc one performs much worse than a Wankel in every way even with their projected improvements.

[Dadhawk]

Originally Posted by serialk11r

I mean he put them on his own flying car, which did fly for a minute (that's a good sign LOL). On a side note, that guy doesn't have gray hair at age 84?? Is that even possible?

I'm not sure the plane actually "flew" with the rotary engines on it (it really more hovered in a tethered ground effect mode than ever really flew). I don't believe the engines during those flights were the rotary ones, but I could be wrong on that. I thought they were developed after the flights to fit the nacelles.

The man is obviously a mechanical genius and a bit of a business savant. He has basically funded his passion by doing "side projects" that made money.

As far as no gray hair, well that's easy to fix, but he is apparently a bit of a health and nutrition nut along with everything else.

Unfortunately, the most recent prototpes were lost in a fire in mid 2019 so I doubt we will ever see the "Voltaire" flying. It's design's time has passed anyway.

I do think the engines have promise.

[Irace86.2.0]

This doesn’t appear to be impressive at all, unless I am missing something. It only takes 10-20hp to maintain 65mph. That is about what a Honda Grom makes with its 150cc motor or 250R makes with its 250cc engine.

The biggest problem with rotary engines is the emissions and efficiency. They are essentially like two stroke engines in that they don’t have valves and don’t separate the oil and the combustion chamber. As such is the case, they can’t modulate and control the air/fuel delivery, and they rely on injecting oil in the combustion chamber to lubricate the rotor. I am not sure how he fixed these issues without causing premature wear and failure, nor do I know how he manages the heat in the chamber that could cause metal fatigue or preignition/detonattion/knock.

[serialk11r]

Originally Posted by Irace86.2.0

The biggest problem with rotary engines is the emissions and efficiency. They are essentially like two stroke engines in that they don’t have valves and don’t separate the oil and the combustion chamber. As such is the case, they can’t modulate and control the air/fuel delivery, and they rely on injecting oil in the combustion chamber to lubricate the rotor. I am not sure how he fixed these issues without causing premature wear and failure, nor do I know how he manages the heat in the chamber that could cause metal fatigue or preignition/detonattion/knock.

That's not correct, they run distinctly separated chambers with no fuel/air mix blowing into the exhaust from the intake.

Lubrication isn't even that much of a problem, because piston engines burn oil too. The rotary just has one hot area where combustion is always happening and oil gets burned a little faster there. Since there's no blowby contamination of the oil, you just slowly burn the oil off (which also happens in most piston engines). Premix is supposed to not hurt cats.

The problem is combustion efficiency. You get those pockets of air/fuel mix near the seals that don't ignite in a timely fashion. Again, there seem to be workarounds, like charge cooling the rotor (aka hot air intake, which reduces torque), adding more spark plugs (the 787B had 3 plugs, there are diminishing returns to adding more but the engine can definitely fit more plugs), using thermal barrier coating everywhere.

The biggest challenge is really the thermal management of the housing, you have one side always running hot, the other side always running cold. Aggressively cooling it down leads to unacceptable heat loss at low speed. Keeping it really hot means more oil consumption and requires ceramic insulation and high temperature coatings.

Efficiency won't ever be as good as a super high compression ratio long stroke piston engine because you can't get the compression ratio and the low surface area/volume ratio, but it works very well if you are always running at high power and weight is important. If you compare it to a motorcycle engine, which also has very little low end torque due to the crazy cam profiles, and also has low efficiency because there's a ton of friction, the rotary looks pretty good.

E.g. on a street car with a 4 cylinder engine, you might be able to shed 150lbs with a rotary, which isn't very impressive if you're hauling over 2500lbs. However if you can take 150lbs off a 1350lb Ariel Atom or 100lbs off a 900lb single seat race car, you probably would actually be using less fuel on the track. A hypothetical all aluminum triple-plug Renesis would be a very attractive engine swap option for track cars.

[Lantanafrs2]

Eclectic guys make a killing with one idea and funnel all their money into a bad idea. Moller ain't the first to do that

[Irace86.2.0]

Originally Posted by serialk11r

That's not correct, they run distinctly separated chambers with no fuel/air mix blowing into the exhaust from the intake.

Lubrication isn't even that much of a problem, because piston engines burn oil too. The rotary just has one hot area where combustion is always happening and oil gets burned a little faster there. Since there's no blowby contamination of the oil, you just slowly burn the oil off (which also happens in most piston engines). Premix is supposed to not hurt cats.

The problem is combustion efficiency. You get those pockets of air/fuel mix near the seals that don't ignite in a timely fashion. Again, there seem to be workarounds, like charge cooling the rotor (aka hot air intake, which reduces torque), adding more spark plugs (the 787B had 3 plugs, there are diminishing returns to adding more but the engine can definitely fit more plugs), using thermal barrier coating everywhere.

The biggest challenge is really the thermal management of the housing, you have one side always running hot, the other side always running cold. Aggressively cooling it down leads to unacceptable heat loss at low speed. Keeping it really hot means more oil consumption and requires ceramic insulation and high temperature coatings.

Efficiency won't ever be as good as a super high compression ratio long stroke piston engine because you can't get the compression ratio and the low surface area/volume ratio, but it works very well if you are always running at high power and weight is important. If you compare it to a motorcycle engine, which also has very little low end torque due to the crazy cam profiles, and also has low efficiency because there's a ton of friction, the rotary looks pretty good.

E.g. on a street car with a 4 cylinder engine, you might be able to shed 150lbs with a rotary, which isn't very impressive if you're hauling over 2500lbs. However if you can take 150lbs off a 1350lb Ariel Atom or 100lbs off a 900lb single seat race car, you probably would actually be using less fuel on the track. A hypothetical all aluminum triple-plug Renesis would be a very attractive engine swap option for track cars.

I never said they were 2-stroke engines, nor did I say they mixed the intake and exhaust gases like 2-stroke engines. I said they are essentially like/similar/share-features of 2-stroke engines in that there are no valves and in that they rely on mixing oil into the combustion chamber.

Now, I don't know how bad it is for emissions to burn oil versus gas, but the Renesis motor recommends 1 qt of oil per 600-1000 miles. That's not an insignificant amount of oil to be burning, and it is no where near what a 4-stroke piston motor would lose across the piston rings. That can't be great for emissions. You mentioned premix. The use of 2-stroke premix oil is common and many use around 1-2 oz per gallon, which is 0.5-1 qt per tank of gas on top of what the engine is mixing into the air/fuel mixture.

I'm not going to get into the fluid dynamics of the rotary engine, except to say that a piston engine has better fluid dynamics for getting a complete burn, and it is easier to modulate because there are valves and because there is an ability to control valve timing and lift. It is even possible to alter effective compression ratio. I'm not saying improvements couldn't be made in efficiency. Here are some possible ways rotary engines could get more efficient, but they would still require burning oil to lubricate the chamber, and on a separate, but related note, the apex seals would still fail and lead to premature engine failure, so I could imagine regulators requiring smog inspections on rotary powered vehicles at shorter intervals like instead of an eight year law for the first smog, it could be at four years.

[ame]https://www.youtube.com/watch?v=vEMuOi0N2fQ[/ame]

[serialk11r]

Originally Posted by Irace86.2.0

Now, I don't know how bad it is for emissions to burn oil versus gas, but the Renesis motor recommends 1 qt of oil per 600-1000 miles. That's not an insignificant amount of oil to be burning, and it is no where near what a 4-stroke piston motor would lose across the piston rings. That can't be great for emissions. You mentioned premix. The use of 2-stroke premix oil is common and many use around 1-2 oz per gallon, which is 0.5-1 qt per tank of gas on top of what the engine is mixing into the air/fuel mixture.

my old 1ZZ-FE MR2 Spyder burned about that much oil. Barely passed the sniff pipe test at 13 years of age, cat was on its way out, but the rod bearings gave up before that due to oil starvation.

The reason I got excited seeing these is because they use roller bearings on the eccentric shaft, and the only oil is for the seals. If I'm not mistaken, you should be able to use straight premix, which shouldn't poison the cats.

A wild guess is that cold start emissions are going to be a problem if the engine spews a bunch of oil and gasoline out, but maybe they can heat it up fast enough to make it work. Not that it matters, I don't think any car OEM is going to ever use these before everyone switches to all electric.

Still, would like one for my future track car The AIEUK (just realized the guy who designed the rotor cooling is the guy who designed the Norton motorcycle engines) 650cc produces 120hp at the 8000rpm limiter...with power still climbing! Imagine a 2 rotor weighing about 90lbs with 260hp.

[WolfpackS2k]

Originally Posted by Irace86.2.0

Scientists are overwhelmingly in agreement that the cause of climate change is entirely man made and linked to greenhouse gas emissions, which principally is CO2.

Even the agencies operating under Trump say climate change is from humans.

https://en.m.wikipedia.org/wiki/Four...ate_Assessment

Hah, well never mind that most of the people at those agencies are carryover. And there's a big difference between believing CO2 is responsible for some warming, and the alarmist view. Let's not sweep under the rug that it's also impossible to determine how much of the warming has been by CO2, and how much other factors. The global average temperature itself is extremely hard to measure and flawed in its coverage. Additionally for every extra molecule of CO2 added to atmosphere, it has half of the effect of the previous molecule. By the laws of physics its impossible for CO2 to be responsible for much more warming.

Originally Posted by Irace86.2.0

Yea, methane is worse, but CO2 might be easier to change. If switching to EVs is this hard then imagine how hard it would be to switch everyone to vegan. Just a note, the waste from the BMW plant in South Carolina goes to a field and the methane produced from the field gets used by the plant to generate around 50% of the energy, if I can remember correctly from the tour.

I'll spoil it for you.



https://www.ess.co.at/GAIA/Countries/methane_total.html

CO2 possibly could be easier to change. Except nobody is embracing nuclear energy. Which is the only way this will happen. Otherwise its close to impossible to change. Paris Accord was a joke. Nobody is following it and even if everyone did (at great economic pain) nobody would even notice it's difference.

[WolfpackS2k]

Originally Posted by Irace86.2.0

Scientists are overwhelmingly in agreement that the cause of climate change is entirely man made and linked to greenhouse gas emissions, which principally is CO2.

Even the agencies operating under Trump say climate change is from humans.

https://en.m.wikipedia.org/wiki/Four...ate_Assessment

Hah, well never mind that most of the people at those agencies are carryover. And there's a big difference between believing CO2 is responsible for some warming, and the alarmist view. Let's not sweep under the rug that it's also impossible to determine how much of the warming has been by CO2, and how much other factors. The global average temperature itself is extremely hard to measure and flawed in its coverage. Additionally for every extra molecule of CO2 added to atmosphere, it has half of the effect of the previous molecule. By the laws of physics its impossible for CO2 to be responsible for much more warming.

Originally Posted by Irace86.2.0

Yea, methane is worse, but CO2 might be easier to change. If switching to EVs is this hard then imagine how hard it would be to switch everyone to vegan. Just a note, the waste from the BMW plant in South Carolina goes to a field and the methane produced from the field gets used by the plant to generate around 50% of the energy, if I can remember correctly from the tour.

I'll spoil it for you.



https://www.ess.co.at/GAIA/Countries/methane_total.html

CO2 possibly could be easier to change. Except nobody is embracing nuclear energy. Which is the only way this will happen. Otherwise its close to impossible to change. Paris Accord was a joke. Nobody is following it and even if everyone did (at great economic pain) nobody would even notice it's difference.