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aostling
08-18-2017, 07:41 PM
Available for the 2019 Mazda 3, the Skyactiv-X will use spark-controlled compression ignition. Supercharged for a great increase in torque, it also will give 20-30% higher fuel economy.

This video explains what is known, and conjectures details as yet unrevealed. http://www.roadandtrack.com/new-cars/car-technology/a12006597/dissecting-mazdas-revolutionary-self-igniting-gas-engine/

Since we are in the conjecture phase, what do you think of this?

H380
08-18-2017, 08:15 PM
It is real. It is a Joint Venture between Mazda and Toyota. So Toyota will be using the tech also.

rohart
08-18-2017, 09:15 PM
May be a great engine technology, but that link crashed my browser good and proper !

achtanelion
08-18-2017, 09:16 PM
I've been following the hcci quest for a while now, and I'm excited to see an example in the wild so to speak. I have no desire to beta test the engine, but I'll be following it's rollout and teething problems closely.

wierdscience
08-18-2017, 11:20 PM
Diesel engine with a spark plug and VVT thrown in?

CCWKen
08-18-2017, 11:48 PM
Don't forget; It was Mazda that tried and failed when using the Wankel engine design. Their engineers couldn't solve the problems with that system. You really think they're ready for a redesigned diesel? If they could ever get it out of their heads that fossil fuels still have a future, development on advanced propulsion will finally get under way.

aostling
08-19-2017, 12:11 AM
Don't forget; It was Mazda that tried and failed when using the Wankel engine design. Their engineers couldn't solve the problems with that system. You really think they're ready for a redesigned diesel? If they could ever get it out of their heads that fossil fuels still have a future, development on advanced propulsion will finally get under way.

According to this article, the Skyactiv X may prolong the future of the internal combustion engine: https://www.nytimes.com/2017/08/17/automobiles/wheels/internal-combustion-engine.html?_r=0.

A salient point is the speed of "refueling." The article quotes an MIT professor, who says


"Holding a gas nozzle, you can transfer 10 megawatts of energy in five minutes," he said, explaining today's refueling reality. To recharge a Tesla electric at that rate today, he said, would require "a cable you couldn't hold."

I did a sanity check on this. Filling a 20-gallon gas tank in five minutes is a fuel flow of 4 gallons/minute. Multiplying this by the heating value of gasoline (114,000 Btu/gallon) gives 456,000 Btu/min, which is an energy flow of 8.02 megawatts. So the prof is right -- the convenience of fast refueling greatly favors petrol.

lakeside53
08-19-2017, 12:16 AM
Failed? Ever driven an RX7/8 etc?

johansen
08-19-2017, 12:32 AM
which is an energy flow of 8.02 megawatts. So the prof is right -- the convenience of fast refueling greatly favors petrol.

a battery of 99% efficiency would still have 80 kilowatts of heat dumped into it while its being recharged at such a rate.

1000 amps at 8KV, yes, you can hold such a cable, though you might need to buy a bigger pair of balls along with the vehicle for stress free refilling... :D

darryl
08-19-2017, 12:41 AM
I have no doubt that the system works- seems to me that various manufacturers produce engines that from time to time will have quite efficient combustion and simply just work well. Not all engines in their various fleets will operate as efficiently. A gain one year is not necessarily passed into the next years models-

At any rate, this reminds me of Smokey Yunick, who did a lot of experimentation on engine design, intake and exhaust plumbing, fuel stratification and mixture smoothness, etc. Because he was well connected in the industry he was given scope to do these experiments. I'd like to say he was a pioneer in the field, but the quest for more power and better economy has been alive for longer that he's been around. I don't know if he's still around- he wrote for some of the popular magazines on vehicle troubleshooting, etc. I seem to recall 'Ask Smokey' as the name of one column, Popular Science it probably was.

The ideas are all old- pretty much everybody knows about fuel/air mixing and how important it is to have a well-prepared mixture in the cylinder, and then an efficient means of igniting it and having it all burn and at the right speed. Various schemes are employed, but usually not all at once. Whether this is something the car makers have had up their sleeves for a long time already or not, it does represent two things- one is that they can and are able to create these 'incredible' engines, and the other is that it leaves nothing left for them to improve on for future engines. Once you have induction, valve timing, ignition, combustion, and exhaust all optimized, how could you ever provide next years 'improved' engines-

It may be that this development by Mazda will basically become the last engine system design, as fuel engines phase out in the next decade or so. At least we'll have a pretty efficient fuel engine to carry us through.

CalM
08-19-2017, 01:47 AM
Don't forget; It was Mazda that tried and failed when using the Wankel engine design. Their engineers couldn't solve the problems with that system. You really think they're ready for a redesigned diesel? If they could ever get it out of their heads that fossil fuels still have a future, development on advanced propulsion will finally get under way.

Yep!

Failed Rotary.

The '79 RX-7 that I drove into town (with a 11A ) was a figment of our collective imagination..

EPA might say "failed", but I say "What a kick in the butt! ;-)

Magicniner
08-19-2017, 05:18 AM
HCCI might explain why no one in the industry is in the least bit interested in all the pretty pictures, animations and utter BS being pumped out by Manolis at Pattakon :D

ikdor
08-19-2017, 06:39 AM
I think the report on the death of the combustion engine is greatly exaggerated. Especially for countries like the US where people drive longer distances on average. The range and speed of refueling are somewhat problematic but people still think with their wallet.
Total cost of ownership is not something people take into account, most people just look at how nice a car looks and how functional it is. The extra investment for the battery takes a long time to recover and human behaviour has not proven very clever in long term financial planning.
The alternative to the electric vehicle revolution is synthetic fuels, and unless govermnent starts to have an active policy everyone will be driving on crops, gas and coal based fuel once oil gets too expensive. The complete infrastructure for liquid fuels is already in place, making it harder for other solutions to take over.
As a second vehicle an electric one with a limited range is nice, but outside of the US few households have two vehicles.

We'll see how it goes with the HCCI, if you operate a gasoline engine like a diesel you will get NOx and particulate issues. The US will probably try to regulate them into the ground to protect their own industry.

Doc Nickel
08-19-2017, 06:49 AM
At any rate, this reminds me of Smokey Yunick, who did a lot of experimentation on engine design, intake and exhaust plumbing, fuel stratification and mixture smoothness, etc. [snip]I don't know if he's still around- he wrote for some of the popular magazines on vehicle troubleshooting, etc. I seem to recall 'Ask Smokey' as the name of one column, Popular Science it probably was.

-Yep. Smokey wrote several books, including a three or four-volume autobiography, and had colums in Popular Science and Circle Track, among others.

Smokey has, unfortunately passed on in 2001 at 78.


It may be that this development by Mazda will basically become the last engine system design, as fuel engines phase out in the next decade or so.

-Highly unlikely, for any number of reasons, not the least of which are the aforementioned refueling speed, the capacity of a "tankful" versus a "charge", cost and complexity of batteries, the simple fact that electrics make poor cold-weather cars, the relative lack of charging stations- and the concurrent unworkable rate at which charging stations would have to be built in order to "phase out" liquid-fuel engines "within a decade"- the fact we barely have enough electrical generating capacity now, let alone enough to replace 200 million gasoline engines, etc. etc. etc.

Barring a significant and as-yet unforseen paradigm change, the liquid-fueled vehicle will be around for many, many decades to come.

Doc.

CCWKen
08-19-2017, 09:31 AM
As soon as someone mentions fossil fuel alternative, why is it that the discussion always turns to batteries? That's the problem with the engineer minds today--No imagination, only duplication. Batteries to propel cars is not a new idea. It's been around since the early 1900s. I can just imagine all the tractor-trailer drivers rolling their eyes when they think they'll have to go to batteries. Get off the battery kick and think of something NEW! We sent guys to the moon and back almost 50 years ago for crying out loud. That made the following 70s the best decade of invention for centuries.

Batteries not included. Think of something else. :)

wierdscience
08-19-2017, 10:13 AM
As soon as someone mentions fossil fuel alternative, why is it that the discussion always turns to batteries? That's the problem with the engineer minds today--No imagination, only duplication. Batteries to propel cars is not a new idea. It's been around since the early 1900s. I can just imagine all the tractor-trailer drivers rolling their eyes when they think they'll have to go to batteries. Get off the battery kick and think of something NEW! We sent guys to the moon and back almost 50 years ago for crying out loud. That made the following 70s the best decade of invention for centuries.

Batteries not included. Think of something else. :)

https://youtu.be/ptlhgFaB89Y?t=13s

;)

RichR
08-19-2017, 11:00 AM
As soon as someone mentions fossil fuel alternative, why is it that the discussion always turns to batteries? That's the problem with the engineer minds today--No imagination, only duplication. Batteries to propel cars is not a new idea. It's been around since the early 1900s. I can just imagine all the tractor-trailer drivers rolling their eyes when they think they'll have to go to batteries. Get off the battery kick and think of something NEW! We sent guys to the moon and back almost 50 years ago for crying out loud. That made the following 70s the best decade of invention for centuries.

Batteries not included. Think of something else. :)

I think I once saw a documentary where they powered a city using pig scheisse, though there was a fuel embargo due to a
political disagreement. But they worked it out by holding a sporting event in a superdome ...... or maybe it was a thunderdome.:rolleyes:

achtanelion
08-19-2017, 11:37 AM
I think the report on the death of the combustion engine is greatly exaggerated. Especially for countries like the US where people drive longer distances on average. The range and speed of refueling are somewhat problematic but people still think with their wallet.

One thing I always bring up when people talk about the electric car revolution is the fact I take a few trips every year into the bush, 300km from the nearest fuelling station. I can bring a few jerry cans of fuel with me and make the trip without range anxiety. I couldn't even reach my destination with most electrics.


The alternative to the electric vehicle revolution is synthetic fuels, and unless govermnent starts to have an active policy everyone will be driving on crops, gas and coal based fuel once oil gets too expensive. The complete infrastructure for liquid fuels is already in place, making it harder for other solutions to take over.
As a second vehicle an electric one with a limited range is nice, but outside of the US few households have two vehicles.

I've looked at a Nissan Leaf as a commuter vehicle, but the marginal cost over just running my regular vehicle is too high. Instead, the best option for me is biodiesel.


We'll see how it goes with the HCCI, if you operate a gasoline engine like a diesel you will get NOx and particulate issues. The US will probably try to regulate them into the ground to protect their own industry.

One of the cool things with HCCI is there is no hot flame front where NOX gets created. Instead the fuel air charge ignites all at once throughout the cylinder. Also you can run quite lean, which reduces particulate formation.

Mazda's engine seems not to be a true HCCI. The best guess is that they're running the cylinders at just under ignition pressure, then firing the spark plug just after TDC. The small amount of fuel igniting from the spark plug is enough to push cylinder pressure over the ignition point, causing the whole charge to light off. A nice workaround to some major problems. Doing otherwise, your charge would always be igniting at TDC (highest pressure condition) in the best case scenario. If your control isn't perfect, you could also end up with your charge igniting before TDC and trying to drive the crank backwards. The other option, of course is the charge never ignites.

enginuity
08-19-2017, 01:12 PM
There are 2 car companies within the giant industry that I have a very high significant engineering respect for: Mazda and Subaru. Both car companies are tiny in comparison to the big ones. Mazda's sales are a drop in the bucket when compared to GM, Ford, Toyota and Volkswagen.

Yet innovation generally does not come from the big auto manufactures - it comes from the small ones. Honda was the first company to build a production hybrid. Mazda was the first car company to produce a production engine without pistons. Some trash the Wankel, but Mazda did what others failed to do and did it on principle. The Wankel was not killed by Mazda, but by the EPA.

Mazda has been saying for years that they feel they can get 20-30% more efficiency out of the gasoline engine. It looks like they are getting closer.

And for all the greenies out there consider this: the well to wheel footprint of lithium ion powered cars is terrible. Most studies say that electric cars are about the same as gasoline powered cars. The cobalt is mined in corrupt third world countries where kids are dying in the mines. Don't believe me? Read it about it in the Washington Post https://www.washingtonpost.com/graphics/business/batteries/congo-cobalt-mining-for-lithium-ion-battery/ Lithium ion batteries are exceptionally difficult to recycle, with most being shipped over to third world countries. People tell me the technology will be developed to recycle them. They have been saying that for years.

Some complain about big oil. And I think there are valid concerns there. But be careful what you wish for. Big electric is not much better. There are numerous boondoggles in the electric generation industry, and it has been my experience that they are similar in nature to big oil. Both sectors have significant monopoly but I would actually argue that there is more competitive pressure in the oil industry than in the electric generation and distribution industry. I can't pick who delivers my electricity, but I can pick where I buy gas.

Do I have an answer to our future energy problems? No, not really. Hydrogen looks promising, but generation of hydrogen isn't efficient.

The interesting thing is that every new technology that has achieved mass acceptance was significantly better and more efficient than the one it replaced. Electric cars are not significantly better than gasoline or diesel powered cars.

Just my 2 cents of course.

Willy
08-19-2017, 02:05 PM
As soon as someone mentions fossil fuel alternative, why is it that the discussion always turns to batteries? That's the problem with the engineer minds today--No imagination, only duplication. Batteries to propel cars is not a new idea. It's been around since the early 1900s. I can just imagine all the tractor-trailer drivers rolling their eyes when they think they'll have to go to batteries. Get off the battery kick and think of something NEW! We sent guys to the moon and back almost 50 years ago for crying out loud. That made the following 70s the best decade of invention for centuries.

Batteries not included. Think of something else. :)

Here's something else, something that has seen some very significant investment by some of the nations largest motor carriers. This could very well be the start of a new direction in high tonnage freight transport.

It`s a big page with lots of info but Id be interested in everyone's opinion on the concept of the Nikola One.
Been fallowing this one for a while now and it looks interesting.

https://nikolamotor.com/one


Even Cummins, long noted for their diesel engine powertrains has acknowledged the fact that electrification is an avenue that must be addressed in order to stay viable in the not too distant future.


In an effort to diversify its commercial transportation product portfolio beyond diesel and natural gas-powered engines, Cummins announced it will introduce a fully electrified powertrain solution for the urban transportation market by 2019 and a range-extended electrified powertrain by 2020.
(http://www.equipmentworld.com/cummins-developing-fully-electric-powertrain-we-are-not-just-a-diesel-company/)

Doc Nickel
08-19-2017, 04:15 PM
It`s a big page with lots of info but Id be interested in everyone's opinion on the concept of the Nikola One.

-Neat idea, but the big issue is where do you get the hydrogen? And I mean both from a local standpoint- IE, how many hydrogen fueling stations are there?- and from a general standpoint- that is, where do we get huge stocks of hydrogen to power a nationwide fleet of these things?

The former can be addressed with time, just as electric car charging stations can and are being addressed with time- as demand grows, more stations are installed, but it will take many, many years to make a full nationwide network.

The latter, well, there's really only two bulk sources of hydrogen- stripping it out of natural gas via steam reformation, which necessarily requires the continued drilling for and use of fossil fuels, and via electrolysis of water, which, of course, requires huge amounts of electricity. The bulk of which we still get from fossil fuels today (primarily natural gas.)

So we either have to keep using fossil fuels, or we have to come up with some way to significantly increase our power generating capacity- most of which use fossil fuels.

Doc.

J Tiers
08-19-2017, 06:35 PM
...
And for all the greenies out there consider this: the well to wheel footprint of lithium ion powered cars is terrible. Most studies say that electric cars are about the same as gasoline powered cars. The cobalt is mined in corrupt third world countries where kids are dying in the mines. Don't believe me? Read it about it in the Washington Post https://www.washingtonpost.com/graphics/business/batteries/congo-cobalt-mining-for-lithium-ion-battery/ Lithium ion batteries are exceptionally difficult to recycle, with most being shipped over to third world countries. People tell me the technology will be developed to recycle them. They have been saying that for years.

Some complain about big oil. And I think there are valid concerns there. But be careful what you wish for. Big electric is not much better. There are numerous boondoggles in the electric generation industry, and it has been my experience that they are similar in nature to big oil. Both sectors have significant monopoly but I would actually argue that there is more competitive pressure in the oil industry than in the electric generation and distribution industry. I can't pick who delivers my electricity, but I can pick where I buy gas.

Electric cars suck about the same as gas right now, and there is no good, self-compelling technology to make it better. We have had electric cars for over 100 years, they have yet to be successful as general transportation, and the best range achievable has been improved less than 2:1 in 100 years. We are STILL stuck with best performance of real (not laboratory) cars at around 100 to 200 miles per charge, AND many hours to recharge, just as it was 100+ years ago.

They were not very practical 100 years ago (that's why they dropped by the wayside), and they STILL are not very practical...... Even the most rabid proponents have been heard to say "well of course you need a second car for many uses". Which is to say that the electric car is not ready even now. It says that either you have to just accept that there are many things you will just not be able to do anymore, or else, that you just cannot have an electric car as your only car.....the electric car is only good as a "second car".
.....


The interesting thing is that every new technology that has achieved mass acceptance was significantly better and more efficient than the one it replaced. Electric cars are not significantly better than gasoline or diesel powered cars.

....

The MORE interesting thing about every new technology that has been successful, is it has been "self-compelling"..... NOBODY needed to pass laws to force you to use it.... it was more a case of regulations being applied afterward due to excessive growth of the technology.

Gasoline and diesel beat steam, not because of laws, but because they were better solutions.

the PC we all use became universal not because we were forced to buy them, but because they made a ton of sense, and were a better solution.

That is not to say there is no place for government support of research, and even early production. Many ideas might not have gotten anywhere if not for external support while they were developing.

But a solution that has to be forced is obviously one that does not "force itself", and therefore it may not be a very good solution.

Now, "better" depends on your goal. If your goal is to have no air pollution inside the city, then the electric car can help that nicely. It may be a "better" solution than an IC engine, although IC engines are getting very good at low pollution. Better at that than they are on mileage/efficiency.

tom37
08-19-2017, 07:42 PM
Look to NSA and the pioneer spacecraft. 5 kw for 20 + years and no failure. Size about 10 inches Diameter and 24 inches long, weight less than 100 pounds. cost millions for one, probably less than $1000.00 in large quantity. Of course nuclear power. Radiation less than background.
Tom w

DICKEYBIRD
08-19-2017, 09:17 PM
Mazda was the first car company to produce a production engine without pistons.Your 2 cents is WAY wrong sir! I worked on, drove (way over the manufacturer's redline by the way) & watched NSU Wankel Spiders race in the MIDDLE 60's! I worked on & drove NSU R080's in 1967. Some of Neckarsulm, Germany's finest. They didn't have the apex seal technology down pat that Mazda came with much later and that caused NSU problems at the time. Should'a put governors on them. They just began to pull REAL strong when the tach hit the redline. Who watches tachs when the thing keeps on pullin'?:D

The other thing that pi$$es me off is that Audi bought NSU & the rest is history. Some VERY innovative engineers & thinkers absorbed by Audi. (Rant over.)

tmarks11
08-19-2017, 09:31 PM
1000 amps at 8KV, yes, you can hold such a cable, though you might need to buy a bigger pair of balls along with the vehicle for stress free refilling... :D

Perhaps the "can't hold that cable" refers to the weight. Marine shore power cables that handle 1000A at 450V are about 4" in diameter and if manually moved take dozens of people to carry them.

tmarks11
08-19-2017, 09:35 PM
Look to NSA and the pioneer spacecraft. 5 kw for 20 + years and no failure...Of course nuclear power. Radiation less than background.

Those used Radioisotope Thermoelectric Generators (RTG), which produced about 40W. Not nuclear reactors. Pioneer 10 had 4 RTG installed.

https://www.nasa.gov/centers/ames/missions/archive/pioneer.html

Andre3127
08-19-2017, 11:00 PM
Don't forget; It was Mazda that tried and failed when using the Wankel engine design. Their engineers couldn't solve the problems with that system. You really think they're ready for a redesigned diesel? If they could ever get it out of their heads that fossil fuels still have a future, development on advanced propulsion will finally get under way.
The rotary is a failure? I think that's quite a stretch. It had trouble with emissions and efficiency but it had quite a positive impact on automobile history and culture. People still built and race them to this day. When built properly they can be quite powerful and decently reliable.

Sent from my XT1053 using Tapatalk

wombat2go
08-19-2017, 11:22 PM
Y Should'a put governors on them. They just began to pull REAL strong when the tach hit the redline. Who watches tachs when the thing keeps on pullin'?:D
(Rant over.)
Yes, that was one problem.
The Mazda RX2 I owned in Australia in 1971 was rated as 1100 cubic centimetre displacement,
but had a dual barrel downdraft carburetor and fuel consumption about the same as a V8 "muscle car"
It was red lined at 7500 RPM and could do that in top gear at about 135 MPH
The price of that car was less than the V8 "muscle cars" of that time,
and it could out accelerate them.

The problem was, the engines had catastophic failure about every 40,000 miles, as I recall.

The ones sent to Australia had dual ignition ( 2 spark plugs per cylinder and a 2 distributors,
The leading one did most of the ignition and the retarded plugs were auxillary.
I recall the retarded plugs were for California compliance, (not sure).

Pre ignition was a common problem in the summer.
The small motor had a large radiator, and was also partly oil cooled.
It had oil injection to fuel from sump which was another problem as there was no low oil warning.
The oil was restricted to the top grade of Shell, at the time. Oil ran hotter than an ordinary engine.
On retarded throttle the fuel/air would carry over into exhaust pipe, and explode,
and could/did blow the exhaust joints apart.

The usual failure mode was water into chamber due to warped rotor chamber.
I also had one engine failure due to a spark plug ceramic tip breaking off due to overheating,
and scoring the chamber inner periphery.

Edit: Another problem
was that the electric reciprocating fuel pump, located in the "boot" ( trunk) used to overheat on hot days,
the armature used to bind in the solenoid,
leading to starvation by low float levels.
Also the RX2 rotary was same body as a 4 cyl car. But for some reason, the RX2 experienced vibrations in front suspension,
that could scare the hell out of driver above about 90 MPH. It was intermittent. My car only had the problem slightly
I think that problem was fixed in the next year. --Memories

MattiJ
08-20-2017, 01:52 AM
It`s a big page with lots of info but Id be interested in everyone's opinion on the concept of the Nikola One.
Been fallowing this one for a while now and it looks interesting.

https://nikolamotor.com
[/URL]

Looks like daydreaming with intent to scam money :p
1200 mile range on compressed hydrogen? Anyone bother to work out the needed volume for the tanks?

MattiJ
08-20-2017, 03:54 AM
I pulled some numbers to check the feasibility of nikola one hydrogen truck:
Loaded 60 ton Diesel euro truck uses about 40l/100km, with 40% efficiency and 35MJ/L that works out to about 560MJ/100km needed at wheels.
Compressed hydrogen at 350bar/5000PSI has practical energy density of about 3.5MJ/L or about ten times worser than diesel. Add to that the fuel cell efficiency of 70% (ignore electric motor and powertrain) and we need 560/3.5/0.7 =230liters of volume in truck for hydrogen per 100km.
To reach the claimed 1200 miles or 1900km range would mean "rather large" hydrogen tank with outer volume of about 4400 liters. :rolleyes:
Diesel truck would need only 800l tanks.

Surely you can go up to 10000 psi but its still considerable volume compared to diesel tank.

Doc Nickel
08-20-2017, 04:44 AM
The rotary is a failure? I think that's quite a stretch. It had trouble with emissions and efficiency but it had quite a positive impact on automobile history and culture. People still built and race them to this day. When built properly they can be quite powerful and decently reliable.

-You could say the exact same thing about the old Ford Flathead. :D

Doc.

ironmonger
08-20-2017, 07:41 AM
If WIKIpedia is to be believed, 96% of industrial hydrogen comes from fossil fuels.

Donít forget the energy that is required to compress hydrogen, although that could be recovered with a mechanical expander like the French compressed air engines. I wonder if the total energy involved would be less if you catalysed methane to propane? Certainly easier to ship and store.

Regardless, just what I need, more competition for the fuel that keeps me from freezing to death in the winter.

Glug
08-20-2017, 09:06 AM
Sometimes rapid advance of tech has a heavy price and being an early adopter isn't all it's cracked up to be.

I have a 2013 Mazda CX5 with Skyactiv and direct injection. Decent car but it has some issues. The oil gets gassy pretty quickly, as widely reported. That makes the 0W20 even thinner than normal. This leads to fears of rapid wear and shorter oil change intervals. A lot of us are wondering and waiting to see whether that will happen, and our cars will be long out of warranty.

Also a big issue - the door hinges on the car have rusted terribly - terribly! Mazda won't do anything about it because it is out of warranty (I made the request and they denied it). The problem was surely present before the end of warranty but not noticed. Many people have reported this. The hinges are cheap, but very difficult to replace - you need to remove the fenders to access the bolts.

The rear hatch mounts also rust out, apparently indicative of the same faulty process that doomed the door hinges. Because having the hatch hit your head is a safety issue, there is a recall.

Ironwoodsmith
08-20-2017, 12:32 PM
Having the doors fall off isn't?

RichR
08-20-2017, 01:03 PM
Having the doors fall off isn't?

They probably figure the hazard created by the door falling off is offset by the safety created by the seat belts and airbags.:rolleyes:

dave_r
08-20-2017, 02:06 PM
They probably figure the hazard created by the door falling off is offset by the safety created by the seat belts and airbags.:rolleyes:

And you are unlikely to be lying down underneath the door when it finally fails...

CCWKen
08-20-2017, 04:30 PM
That's the Mazda engineers hard at work. :)

"Mazda, named after the highest god of Zoroastrianism of all things", happens to be an Iranian religion. Go figure. I think it's terrorism by design. :cool:

oldtiffie
08-20-2017, 09:40 PM
Available for the 2019 Mazda 3, the Skyactiv-X will use spark-controlled compression ignition. Supercharged for a great increase in torque, it also will give 20-30% higher fuel economy.

This video explains what is known, and conjectures details as yet unrevealed. http://www.roadandtrack.com/new-cars/car-technology/a12006597/dissecting-mazdas-revolutionary-self-igniting-gas-engine/

Since we are in the conjecture phase, what do you think of this?

I have a Mazda 3 top of the range SP25 Astina with Skyactiv technology - and it is a superb family car in all respects and meets all of our needs.

I has every Mazda "extra" on it and it is faultless in all respects for our needs.

Typically it has all of Mazda\s attention to performance. finish and detail and local Dealer support and maintenance is all that I could wish for.

https://www.google.com.au/search?q=mazda+3+skyactiv+technology&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjNrOOZmefVAhWLUbwKHfuiAfYQ_AUICigB&biw=1536&bih=719

https://en.wikipedia.org/wiki/SkyActiv

Andre3127
08-20-2017, 10:49 PM
-You could say the exact same thing about the old Ford Flathead. :D

Doc.
I don't think people take Model A's down the quarter mile in under seven seconds :)

High HP rotary's usually have a third or even fourth rotor fitted, whereas rx7's came with a two rotor engine.

Sent from my XT1053 using Tapatalk

A.K. Boomer
08-20-2017, 11:11 PM
Said this before on here and will say it again, not real impressed with Maz-duh's approach to things --- their best bet is to follow the leaders and just try to figure out a way of making it cheaper...

Oh and uh --- Rotaries are junk --- they have no energy return system and they guzzle fuel...

Doc Nickel
08-20-2017, 11:17 PM
I don't think people take Model A's down the quarter mile in under seven seconds :)

-"Under"? No. But close. :D How about 7.695 @ 174.96 MPH (https://www.hotrodhotline.com/rick-schnell-and-worlds-quickest-flathead-dragster#.WZpQPj6GNhE)? :)

Doc.

Doc Nickel
08-20-2017, 11:31 PM
Before this devolves into a "my engine is better than your engine" argument, the simple fact is there are just too many limitations to the Wankel format to really make it viable.

Does it work? Sure. Does it work well? Indeed.

The problem is, today the auto manufacturers are under tremendous pressure to improve fuel efficiency, both from a legal standpoint (such as CAFE requirements) and from a marketing standpoint (apart from trucks and sports cars, one of the biggest drivers in vehicle selection choice is mileage.) Plus market pressure- from other manufacturers and from the buying public- is on ever-longer vehicle lifespans.

When I was in high school, a car with 100K miles on it was a worn out, clapped-out pile of junk. Today a car is expected to be able to reach 180-200K without any major repairs (IE, transmissions or engines- things like brakes and such are expected to be replaced.) My current daily driver is a 20-year old Ford with 180,000 miles on it, and I'm confident enough in it I have zero qualms about taking it on a 400+ mile round trip every couple of weeks.

Modern cars are not "allowed" to have things like excessive oil consumption, excessive emissions- even at 180K miles- low mileage, low power, or frequent, expensive repairs.

The Wankel is an interesting design, but it's just not competitive anymore in today's market.

Doc.

danlb
08-21-2017, 12:03 AM
My fading memory is that the Wankel was able to get good mileage and good power good reliability in a light package. What it could not do was all of the above without excessive emissions. My RX7 was gutless compared to the wife's Camero or my 1100cc Suzuki.

I have to wonder what tricks will have to be used in a spark-controlled compression ignition engine to achieve excellence in all four areas. Last time I used an engine with a spark-plug and oily fuel mixture it was hard on the spark plugs. I had to clean them quite frequently. Of course, that was a single cylinder 2 stroke motorcycle, not a computer controlled 6 cylinder with fuel injection.

Dan

ikdor
08-21-2017, 02:20 AM
The other thing that pi$$es me off is that Audi bought NSU & the rest is history. Some VERY innovative engineers & thinkers absorbed by Audi. (Rant over.)

Well they got their revenge, at least one of them had to be pulled out of retirement when they were working on wankel based range extender for their electric vehicle.

achtanelion
08-21-2017, 05:28 AM
Said this before on here and will say it again, not real impressed with Maz-duh's approach to things --- their best bet is to follow the leaders and just try to figure out a way of making it cheaper...


Mazda's willingness to try new stuff is the only thing that's interesting about them. I just wish they made a vehicle for my needs.


My fading memory is that the Wankel was able to get good mileage and good power good reliability in a light package. What it could not do was all of the above without excessive emissions. My RX7 was gutless compared to the wife's Camero or my 1100cc Suzuki.

I have to wonder what tricks will have to be used in a spark-controlled compression ignition engine to achieve excellence in all four areas. Last time I used an engine with a spark-plug and oily fuel mixture it was hard on the spark plugs. I had to clean them quite frequently. Of course, that was a single cylinder 2 stroke motorcycle, not a computer controlled 6 cylinder with fuel injection.

Dan

SPCCI should be good on:

Power with the supercharging and lean burn

Mileage with the lean burn and Atkinson cycle

Emissions since SPCCI has no (well, OK minimal) hot flame front for NOX to form in, plus the lean burn should reduce load on the cat. It's possible it will have particulate problems to deal with like a diesel, but I don't think likely.

Reliability, well that ball's in Mazda's court now.

All in all, pretty cool to see though.

Danl
08-21-2017, 02:13 PM
-"Under"? No. But close. :D How about 7.695 @ 174.96 MPH (https://www.hotrodhotline.com/rick-schnell-and-worlds-quickest-flathead-dragster#.WZpQPj6GNhE)? :)

Doc.

For a little perspective, consider that the Ford V8 flathead was produced by Ford for 50 years, with over 10 million of them rolling off assembly lines.

Dan L

Andre3127
08-21-2017, 11:53 PM
Before this devolves into a "my engine is better than your engine" argument, the simple fact is there are just too many limitations to the Wankel format to really make it viable.

Does it work? Sure. Does it work well? Indeed.

The problem is, today the auto manufacturers are under tremendous pressure to improve fuel efficiency, both from a legal standpoint (such as CAFE requirements) and from a marketing standpoint (apart from trucks and sports cars, one of the biggest drivers in vehicle selection choice is mileage.) Plus market pressure- from other manufacturers and from the buying public- is on ever-longer vehicle lifespans.

When I was in high school, a car with 100K miles on it was a worn out, clapped-out pile of junk. Today a car is expected to be able to reach 180-200K without any major repairs (IE, transmissions or engines- things like brakes and such are expected to be replaced.) My current daily driver is a 20-year old Ford with 180,000 miles on it, and I'm confident enough in it I have zero qualms about taking it on a 400+ mile round trip every couple of weeks.

Modern cars are not "allowed" to have things like excessive oil consumption, excessive emissions- even at 180K miles- low mileage, low power, or frequent, expensive repairs.

The Wankel is an interesting design, but it's just not competitive anymore in today's market.

Doc.
Yup, I totally agree. It's also known to have problems with the oil injection pump and flooding. These engines burn oil by design, so emissions will never be up to today's standards.



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Andre3127
08-21-2017, 11:54 PM
-"Under"? No. But close. :D How about 7.695 @ 174.96 MPH (https://www.hotrodhotline.com/rick-schnell-and-worlds-quickest-flathead-dragster#.WZpQPj6GNhE)? :)

Doc.
That project was built to prove a point to a buddy of his. I guarantee it!

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