GM unveils diesel-like gasoline engines

[cfg83]

Hello -

This looks promising :

Drivable concept versions of General Motors cars that use efficient new engines with HCCI technology revealed Friday.
August 24 2007: 3:07 PM EDT
http://money.cnn.com/2007/08/23/autos/gm_hcci/index.htm

NEW YORK (CNNMoney.com) -- General Motors revealed two drivable concept cars with new engines that burn gasoline in virtually the same way that a diesel engine burns diesel fuel.

The engines will get 15-percent better fuel economy than ordinary gasoline engines, GM estimates, but will not need the expensive exhaust treatment that diesel engines require.

GM is revealing the fuel saving diesel-like gasoline engine in a version of the Saturn Aura.

Several car companies have been working on this type of engine technology, commonly known as homogeneous charge compression ignition, or HCCI. The technology promises the fuel economy of a diesel engine, which is typically much more efficient than a gasoline engine, but with the much cleaner exhaust of a gasoline engine.

In an HCCI engine, gasoline is ignited inside the cylinder using compression and the engine's own heat without the need of a spark. This is the same way that a diesel engine ignites diesel fuel. (When the engine is first started, and until it warms up, GM's HCCI engine still uses a spark to ignite the fuel.)

This type of ignition results in more energy to propel the vehicle because the fuel burns with less heat and light, which wastes energy, and because there is more compression when the fuel is ignited and, therefore, more of a push when the fuel and air expand.

I've been reading about HCCI in the last few years (greencarcongress?!?!?!?), but I forget the details.

CarloSW2

[rh77]

This is an interesting design -- I haven't heard of it yet.

I looks like NOx is significantly reduced, but hydrocarbons are similar (depending on consumption) vs. a traditional gasser. The manufacturer traditionally claims higher estimates of power, economy, etc... so I'm guessing 15% is a bit optimistic. But, it may be too early to tell.

Another thing: longevity. Reading more about it shows that it's quite complicated to manage the combustion process -- and with the much higher compressions, will it be durable?

I hope it's not like Cadillac's early 80's V2-4-8 system that failed miserably...

RH77

[psyshack]

rh77

Honda has been working on a engine like this for many years. When they get it done right. It will be right. The controls as I understand it are hellish.

My grandfather worked a lot on this type of combustion in the late 40's and early 50's. It led him to the use of ceramics and other materials that led to his scavaging rocket engine.

In the ice he just couldn't control the engine. He did a lot with varible speed super chargers and such. Burning valves was a issue also. Again back to control.

[rh77]

Originally Posted by psyshack

rh77

Honda has been working on a engine like this for many years. When they get it done right. It will be right. The controls as I understand it are hellish.

My grandfather worked a lot on this type of combustion in the late 40's and early 50's. It led him to the use of ceramics and other materials that led to his scavaging rocket engine.

In the ice he just couldn't control the engine. He did a lot with varible speed super chargers and such. Burning valves was a issue also. Again back to control.

That's pretty cool -- both "Rocket Science" and vehicle engine design -- I bet it was a fun job Sounds like he got to work on some cutting edge stuff back in the day.

If Honda's working on the design, then you're right -- it won't be released unless it meets their rigorous standards. So, I wonder how serious GM is with moving this into their fleet of vehicles, and how they overcame the problems such as exhaust gas temps vs. burning valves, etc???

I'm curious as to what other engine designs are floating around there in test mills. Maybe a quick poll of the members can shed some light...(new thread anyone?)...

RH77

[psyshack]

rh77

He was a old school tool and die maker. With a talent for invention.

His claim to fame was what we call the muffler. LMAO. He invented the first machines to make what we now cal the modern muffler. The so called seamless muffler.

He also had a lot to do with invention of modern concrete spray applications.

His stock and trade was plastic molding injection. He and his brothers made the first bubble canopy's for jet age fighter aircraft.

His love was propulsion. He loved super chargers. He enjoyed lean burn engines. His crowning achievement was the savaging rocket. It can be started and ran on fuels like coal oil, or gasoline. Then be lean out to run on hydrogen scavaged from the atmosphere. He made his final prtotype to propel a boat @ 150 hp. Yes,,, it ran under water and was the size of a shoe box.

It was never boring at granpa's house or tool and die shop.

[rh77]

That's awesome! It sounds like he lived the TV Show "Modern Marvels"!

If I only had the passion and smarts for such projects

Originally Posted by psyshack

rh77

He was a old school tool and die maker. With a talent for invention.

His claim to fame was what we call the muffler. LMAO. He invented the first machines to make what we now cal the modern muffler. The so called seamless muffler.

He also had a lot to do with invention of modern concrete spray applications.

His stock and trade was plastic molding injection. He and his brothers made the first bubble canopy's for jet age fighter aircraft.

His love was propulsion. He loved super chargers. He enjoyed lean burn engines. His crowning achievement was the savaging rocket. It can be started and ran on fuels like coal oil, or gasoline. Then be lean out to run on hydrogen scavaged from the atmosphere. He made his final prtotype to propel a boat @ 150 hp. Yes,,, it ran under water and was the size of a shoe box.

It was never boring at granpa's house or tool and die shop.

[trebuchet03]

Originally Posted by rh77

That's awesome! It sounds like he lived the TV Show "Modern Marvels"!

That show is awesome..... One of a few things I'll watch semi frequently (although, they do screw up on occasion ). Sorry to hijack, just wanted to throw that out there.

[rh77]

Originally Posted by trebuchet03

That show is awesome..... One of a few things I'll watch semi frequently (although, they do screw up on occasion ). Sorry to hijack, just wanted to throw that out there.

Sorry for the triple-hijack as well, but I love that show too! (Watching it now on DVR). Probably my favorite series for a few years now...

Although I did get into "Ice Road Truckers" as well

RH77

[cfg83]

rh77 -

Originally Posted by rh77

Sorry for the triple-hijack as well, but I love that show too! (Watching it now on DVR). Probably my favorite series for a few years now...

Although I did get into "Ice Road Truckers" as well

RH77

I never mind a hijack if I like the subject.

Ice Road Truckers was AWESOME. But, I can tell they played with the audience. They never told you that TJ could have been at one of the portages when he went missing. I'll bet that portage 49 doesn't have a communication link.

The Yellow Knife locals seemed to know what they were doing. If Hugh had ponied up a foot heater for Drew, they might still be friends.

CarloSW2

[rh77]

I agree, they played the audience quite often -- and tended to repeat footage on subsequent episodes. But nevertheless, it was a neat view into this little-known industry.

Hugh was probably showing off for the camera 99% of the time -- we've all met guys like that -- frankly, I think he came off as an arse. He didn't take care of his employees -- as you said, he could've had Rick stay on with a simple heater repair.

My fav's were Jay and Alex: they had the most honest personalities of the bunch.

I hear there's going to be a Season 2, so that's cool

Originally Posted by cfg83

rh77 -



I never mind a hijack if I like the subject.

Ice Road Truckers was AWESOME. But, I can tell they played with the audience. They never told you that TJ could have been at one of the portages when he went missing. I'll bet that portage 49 doesn't have a communication link.

The Yellow Knife locals seemed to know what they were doing. If Hugh had ponied up a foot heater for Drew, they might still be friends.

CarloSW2