The death of diesel #351

[Drago]

Now, this is very interesting indeed.

http://jalopnik.com/mazdas-upcoming-skyactive-x-compression-ignition-engine-1797643172

Mazda have sussed out how to make a petrol engine use compression cognition at certain points in the rev range, while relying on conventional spark ignition at points in the range where its more efficient to do so.

What they end up with this the holy grail - a diesel like engine with ignition advance, and a petrol engine with, they say, better economy than their own diesels.

Internal combustion is on its way out slowly for sure, but this last hurrah of super clean, super economical, super quiet and smooth engine is very, very interesting. Had it come along 15 years ago then the march of electric might be delayed by decades.

I know I'm using the word interesting a lot, but it is jolly interesting.

 

[swansonj]

Now, this is very interesting indeed.

http://jalopnik.com/mazdas-upcoming-skyactive-x-compression-ignition-engine-1797643172

Mazda have sussed out how to make a petrol engine use compression cognition at certain points in the rev range, while relying on conventional spark ignition at points in the range where its more efficient to do so.

What they end up with this the holy grail - a diesel like engine with ignition advance, and a petrol engine with, they say, better economy than their own diesels.

Internal combustion is on its way out slowly for sure, but this last hurrah of super clean, super economical, super quiet and smooth engine is very, very interesting. Had it come along 15 years ago then the march of electric might be delayed by decades.

I know I'm using the word interesting a lot, but it is jolly interesting.

Wow, that's interesting

 

[Chromatic]

Wow, that's interesting

You beat me to it, although I wan't going to be quite so verbose, I was just going to say 'Interesting'.

 

[mustang1]

Cheesy.

 

[Oldfentiger]

I don't pretend to fully understand why this engine is so much more efficient and clean, but it's chucked a few questions up for me.

I thought that diesel has a higher calorific value than petrol, hence higher torque and more mpg. How does this new engine reverse that theory?

I thought that petrol requires a much higher compression ratio to achieve compression ignition (hence the need for a spark).

Whichever way you burn petrol (a hydrocarbon), the products of combustion will be CO and CO2, which apparently will kill us all eventually.

Whatever happened to the hydrogen engine? Product of combustion is harmless water.

I like Mazda, and I know they are a lot cleverer than I am so I'm gonna sit here and wait to be educated.

 

[Drago]

Diesels calorific value is 44800 kj/kg, petrol is 47300, so petrol is the more energetic fuel. Up until now the thermal efficiency of diesel has been better, so more of the fuel is turned into heat and power.

Lots of speculation, but Mazda are keeping tight lipped about the details.

Hydrogen is great in-use. Reasonable range, quick refuel, but cracking the hydrogen from water requires a lotnof fossil fuel to be burned to power the process, and an entirely new infra structure.

 

[Levo-Lon]

Let's be honest..
If our world wasn't controlled by oil ,we would have been seeing just water from exhaust pipes for years..
The hydrogen engine would be the thing.
How many patents have been bought by oil barons and any govt with a vested interest in oil wealth to stop any real progress in a cleaner world

 

[Oldfentiger]

Diesels calorific value is 44800 kj/kg, petrol is 47300, so petrol is the more energetic fuel. Up until now the thermal efficiency of diesel has been better, so more of the fuel is turned into heat and power.

Lots of speculation, but Mazda are keeping tight lipped about the details.

Hydrogen is great in-use. Reasonable range, quick refuel, but cracking the hydrogen from water requires a lotnof fossil fuel to be burned to power the process, and an entirely new infra structure.

Thank you.
See, who needs school when you can come to CC instead?

 

[Profpointy]

Let's be honest..
If our world wasn't controlled by oil ,we would have been seeing just water from exhaust pipes for years..
The hydrogen engine would be the thing.
How many patents have been bought by oil barons and any govt with a vested interest in oil wealth to stop any real progress in a cleaner world

Not a very plausible claim and easily checked by looking up all the patents which have been "bought up" and sat on.

 

[raleighnut]

I still think this idea would offer more efficiency as you get the burnt charge to do more work before it is exhausted.



View: https://youtu.be/u0uPmrSRM7w

 

[KnackeredBike]

The hydrogen engine would be the thing.

The hydrogen engine is a "thing" but there isn't a way of producing lots of hydrogen at the moment which doesn't involve fossil fuels and/or loads of energy.

As does electricity but to a lesser degree.

 

[Drago]

The oil companies missed a trick - they could be well established by now with huge oil and gas powered plants doing nothing but cracking hydrogen.

 

[DaveReading]

Mazda have sussed out how to make a petrol engine use compression cognition

Sounds like something that would make your brain hurt.

 

[green1]

Let's be honest..
If our world wasn't controlled by oil ,we would have been seeing just water from exhaust pipes for years..
The hydrogen engine would be the thing.

Funnily enough Mazda have also been developing that. Wankel engines can run on hydrogen simply by changing the injectors. Rx8's were used on the hydrogen highway in Norway.

 

[Wobblers]

Diesels calorific value is 44800 kj/kg, petrol is 47300, so petrol is the more energetic fuel. Up until now the thermal efficiency of diesel has been better, so more of the fuel is turned into heat and power.

Lots of speculation, but Mazda are keeping tight lipped about the details.

Hydrogen is great in-use. Reasonable range, quick refuel, but cracking the hydrogen from water requires a lotnof fossil fuel to be burned to power the process, and an entirely new infra structure.

Your car already runs on hydrogen. It's just that it's attached to carbon atoms so that it can be stored in a more handy form (petrol!). Everyone looks at the heat of combustion of hydrogen, thinks "Wow! Three times that of petrol!" and stops there. Unfortunately, it being thte lightest gas in the universe, you can't fit terribly much of it in your car. The most feasible method we have is to liquify it (at ruinous energy cost) and even then, it still has less than half the energy in a litre than the equivalent litre of petrol. Your hydrogen car will have less range than conventional ones, alas. Then there's the fact that it's a cryogenic liquid, at minus 253 C; this is not something that easy to handle. Given the number of muppets infesting our roads, just how many do you want to be dealing with liquid hydrogen! What could possibly go wrong?