Hey, remember Delphi Powertrain? Once upon a time, it was part of GM, and it developed advanced concepts in — you guessed — powertrains. Since it failed to provide employment to enough grinning MBAs, however, it was shucked aside and cored-out like many other productive parts of the Artist Currently Known As Old General Motors.
Turns out, however, that the venture-capitalized folks working there are still making interesting things happen, and we aren’t talking about the V8-6-4 this time, either.
MIT’s Technology Review took a step away from their normal fare of celebrity gossip and short-fiction erotica today to report that Delphi has a single-cylinder compression-ignition engine up and running. This is not particularly interesting, since a fellow named Rudolf Diesel did it a long time ago without the aid of even a single iPad.
The jaw-dropper is this: this “diesel” engine uses gasoline. A direct-injection system pulses three precisely timed bursts of fuel during the compression-ignition cycle, and said fuel is reliably ignited without the hassles and inefficiencies of sparking.
Why’s this useful? Well, this engine could produce diesel-like fuel efficiency using plain gasoline, which can require up to 15% less crude oil per gallon to produce than diesel — and, not incidentally in these self-ashamed times, produces up to 15% less CO2 per gallon consumed. Also, and I am certain some diesel loyalist will firebomb my house for saying this, it seems to be generally acknowledged that the particulate emissions of diesel engines are both uniquely carcinogenic and difficult to trap. There’s also the fact that diesel fuel is sticky, doesn’t evaporate, gets all over your shoes, and is psychologically associated for some of us with the unique Interstate cultural phenomenon known as the “lot lizard”. But I digress.
Just like a diesel engine, this compression-ignition gasoline engine will no doubt require a variety of strategies to start and run correctly in cold weather. The Delphi engine already re-routes exhaust gas to re-heat the cylinder head in some circumstances. Glow plugs aren’t mentioned in the article but they are probably necessary. Diesel’s greatest cold-weather problem, however, is fuel composition and “gelling”, and gasoline is free from that worry.
Delphi’s scientist told MIT’s journalist that the engine could certainly be paired with a hybrid system to improve efficiency further, although “it’s not clear whether doing that would be worth the added cost.” Silly scientist! I bet he sits around at night and wonders whether the pedestal spoiler on the ’95 Grand Am actually reduces lift at high speeds. Nice to see there’s still some innocence in the world, huh?
Haven’t Mercedes (DiesOtto) and GM both demonstrated HCCI engines before?
Yes, but… this one is described as being much closer to production-ready status. It’s always been possible to do compression ignition in *some* controlled circumstances, but the Delphi engine apparently is potentially fit for life outside the lab.
A number of prototype projects from various manufacturers are listed here:
http://en.wikipedia.org/wiki/Homogeneous_charge_compression_ignition
I don’t care who gets there first – diesel efficiency without the diesel downsides can’t come soon enough.
It’s hard to see how this single-cylinder workbench engine is closer to production-ready status than the modified 2.2 Ecotec 4-banger that GM had installed in a streetable Saturn a few years back. They were able to get all the components under the hood.
Maybe Delphi has some new tricks that should make the engine cheaper to manufacture or a design that allows the most expensive and critical components longer lifetimes.
Based on what? I work in the field and the issue has always been combustion stability at high speed. Honda and Ford are the leaders in HCCI as they have been working on it for well over a decade and have published several SAE papers on the subject. They also have multi-cylinder prototypes based on production engines. However, I have yet to see any HCCI application run at over 4000RPM without uncontrollable detonation.
Also, Delphi (Hyundai is also one of the major partners in the project) is getting a crapton of government (DOE) money for this, which just makes it that much more annoying. I’ve read a couple of their papers and haven’t seen anything spectacular that differentiates this from anything else that’s been published. Meh.
The particulate emissions from diesel engines aren’t only related to the fuel thats burned; they have a lot more to do with the mixing. GDI engines are beginning to have the same problem and will likely require particulate filters in the future as they start running leaner & more stratified; however IIRC Gasoline produces even smaller, harder to filter particles since it vaporizes & mixes more quickly, and the particles don’t tend to agglomerate during the expansion/exhaust strokes as much as diesel.
ChrisH: Didn’t Ford have an engine with auxiliary injection of Ethanol to cool the charge and raise the compression?
“Also, and I am certain some diesel loyalist will firebomb my house for saying this…”
With SVO, dyed, ULSD or (perish the thought) gasoline? That’s really the question.
In the late 90’s they were running 14.1 compression engines in Nascar. Which is about the same as diesel. So gas can definitely be squeezed that far.
That’s the spec of Mazda’s new SkyActiv engines as well…
Sorry, that’s an overly simplistic apples-and-oranges comparison.
NASCAR engines run on special high-octane race gas, which you can’t get at the corner gas station and wouldn’t want to pay for if you could (over $7 per gallon).
Also, the effective compression pressure in the cylinder is governed not just by the calculated CR but by the camshaft profile, particularly the intake valve closing point. The cams in NASCAR race cars would not be acceptable in street cars, both in terms of driveability and probably emissions.
Thats about the same as a very tired diesel try 20.1
If it’s HCCI without the complexity of the dynamic compression, then ‘hurrah.’ The day Delphi is associated with anything other than outsourcing overpaid union jobs, blown out cities like Flint and Dayton and craptastic part quality will be a cold day in hell.
Upon examination of this: http://www1.eere.energy.gov/vehiclesandfuels/pdfs/merit_review_2011/adv_combustion/ace053_szybist_2011_o.pdf
It appears they’re a ‘me too’ of Diamler: Hydraulic Valve actuation or their cam based VVA system.
And it’s the DOE, not Delphi.
I have to wonder what the mileage for a thing like this would be if it was combined with hybrid power in a car about the size of a Jetta. 65mpg?? I personally would buy if it hit somewhere between 65-70 on the hwy and cost less than 40K. All this while holding about 16 gallons of fuel I could go for about a 9 days with out fueling up.
Thing is, there’s not a whole lot of gain to be had in pushing MPGs much past 50. It’s wildly expensive to develop, yet has little real world benefit aside from marketing bragging rights. Whoever came up with the MPG metric did more harm than good.
For instance, increasing a truck’s mileage from 9mpg to 10mpg makes a bigger difference than increasing the Prius’s 50mpg to 100mpg. Even though the truck would only see an 11% gain in MPGs versus the Prius improvement of 100%, the truck’s small improvement would save more gas. Or, as an old Motor Trend (I think?) article put it: “It’s about the gas, stupid! (not the MPGs)”
Sure, more MPGs will always be welcome, but the cost/benefit becomes prohibitive at a point.
Yeah I hate it that my diesel Citroen only gets 54mpg and the newer ones get over 60mpg but I have to pay for my fuel myself and gas is $2.20L and diesel $1.56
PS – I wholeheartedly agree that larger fuel tanks are needed in efficient cars. It was infuriating to own a first gen xB, which was remarkably versatile and good on gas, yet had a max range of 300 miles due to a ~10 gallon tank.
PPS – According to your numbers, you drive 30k+ a year. As it is, you can get a Prius for about half of your allotted $40k, and probably save a helluva lot of cash on gas.
Yeah, but then he’s stuck driving a Prius.
Very hard to beat the MPG that a Prius gets using the EPA cycles, but lighter weight will make a difference in city driving until the EPA does some user surveys and readjusts the fudge factor that goes into the number on the Mulroney sticker.
A Prius/Camry atkinson cycle engine has diesel-like efficiency (38%) at much lower costs.. its a light engine, no direct fuel injection, no turbo and no expensive catalytic converters needed. Expect to see more atkinson engines on the market.
As a diesel fan, I still like it. Sorry, Jack, no hate.
Maybe I am really a compression fan and never really thought about the difference.
Ford somehow perfected this technology in my ’78 Fairmont.
Did it diesel on shutdown? My dad’s ’70 Buick did that so badly that we could leave it in gear, step on the gas as it was dieseling, and drive it with a huge clatter and massive amounts of smoke. This was in the late 70s when I was in middle school and was embarrassing as hell in front of my friends.
Yeah, it would diesel on shutdown, sometimes for a few minutes at a time if I let it. Since it was a manual, I’d just dump the clutch with the car in 3rd and it would finally stop.
@grzydj: damn you! I laughed a booger on my shirt. locked out of my 70’s Mopar (running to keep the windshield from icing while I got cash from an atm) I had to stall it while I got a lift to get the other key. My brain doesn’t work well at anything below 10F, so I pulled the coil wire from the distributor. Freakishly yellow Accell super coils still make me cringe. that car dieseled for what seemed like minutes while I struggled to let go of the wire.
My mate once drove his 73 Holden 40 miles or so with no spark, due to a dead alternator & consequent flat battery, it wouldn’t even run the dash warning lights. Don’t think that is the future of motoring though!
As already mentioned, Delphi isn’t the only one working on this, with most of the differences between them & Mercedes, GM, Ford etc in the control strategy. The big problem is how to maintain sufficient stratification in temperature or composition (fuel-air-EGR-fuel2? mixture) so that all the fuel burns relatively quickly & completely, but not too quickly as in pure HCCI (knocking).
It seems that Delphi is doing this through mainly fuel stratification w/3 pulses, allowing a semi-homogeneous “layer” with the first pulse, and then adding the necessary stratification and timing control with the second & third pulses such that the total amount of fuel delivered determines the load, and it all goes up quickly but not too quickly.
Other ways include RCCI, which is adding a diesel ‘spark’ to ignite a mixture that’s close to auto-ignition, HCCI which really relies on mixture preparation & temp when compression starts too much to be viable on its own, SACI which uses a spark to initially ignite a stratified (overall lean, rich near the spark plug) mixture, burning 5-10% in flame propagation which compresses & heats up the rest so that it auto-ignites.
Delphi does seem to be one of the leaders as far as making it possible for production tho
Where do you live again, Jack? Ohio, right? Just kidding.
As a TDI fan/driver, this is pretty impressive. Gelling is a huge problem in the winter so if they can successfully use gasoline in a compression engine, that’s quite a feat. I’d be interested in this if it ever makes it to a production vehicle.
And they’re not just known as lot lizards. They’re also “friends of the road” as Ray taught me in Trailer Park Boys.
There are no magic bullets at this point in history. Just lots of variables to trade off including fuel, compression, spark, cooling, durability, emissions, materials, weight, … there will continue to be better and worse solutions for different uses in different environments.
Where’s the bsfc data?
“15% less CO2 per gallon consumed”
This is nonsensical. A gallon of gasoline has a fixed amount of carbon in it. What does that carbon turn into if not CO2? Particulates? CO?
I read that claim as “gasoline produces 15% less CO2 per gallon burned when compared to diesel”. Given the comparatively higher mass fraction of carbon in diesel (higher density and generally longer HC chains), this sort of makes sense.
Yeah, that makes more sense. They’re comparing gasoline to Diesel, not the two different engines both burning gas. A regular gas engine would produce the same CO2/gallon as this fancy Delphi thing. It’s intrinsic to the fuel. Methanol would be even better.
What about the power loss diesel has more BTUs than gas
“Also, and I am certain some diesel loyalist will firebomb my house for saying this”
I’ve been thinking of firebombing you for quite some time now…along with a dude who runs the local Dunkin Donuts store(I don’t want to get into it)…..but have you seen the price of fuel lately?
Jack, the last time you bent over this far was when you were glossing who didn’t really, ok he did, Lutz … let’s use a real fuel and stop licking BigO’s rear: biodiesel from animal tallow. Cetane rating of 65 before my chief chemist spanks it. Navy, Army, Marines, Air Force love it. You my friend, are spending a little too much time trolling and not enough time, racing in the real world of performance bio-diesel. We’re bringing back a C111-II-Diesel inspired supercar to life. Bourbon is on the house. Come for a visit. Vodka McBra not welcome. We’re a “family friendly” enterprise. That said, there’s Motel 8s a-plenty or the Conde-Nast hotel of the year down the road.
Great. Now my old Benz can smell like a Baconator.
Only Jack would work a reference to “lot lizards” in an article about new engine tech.
I like this, now if they could pull something off using sensors to detect specific fuel mix and gravity we could have a LDS-427 like in my M35 Duce and a half that has real power and works in the real world with any fuel. I look forward to seeing more of what they have to offer in the future, because this is a good direction to go in I have a feeling. Best yet a adaptation for real multifuel perhaps.
This sounds like really promising technology. Let’s hope it gets fast-tracked into commercial development.
What does the valve train look like? Perhaps a junk head and sleeve valves? No auto ignition from poppet valves being hot!
GM had gasoline powered diesel cars on the road in the 70’s!!
My Chevy Monza with the awesome Vega 4 cylinder mill would diesel all day when you turned off the ignition. It was a manual, when I parked it, I had to put in the clutch, put it in fifth gear and let out the clutch to get the engine to stop. I wound up trading it for a Monte Carlo with a 305 V-8 that had to have the auto trans manually shifted into second gear just to get up a hill. One day the crankshaft snout just – snapped off! I think the crank was made of pot metal. That was the last GM car in my life. Period.