Direct Injection - No Spark Plug


#1

Yes I know what you’re thinking - Diesel. But no - This gas. Hyundai and Delphi are working on a direct injection engine using Gas that doesn’t require a sparkplug.

They are hoping for a 15% increase in engine efficiency. We’ll see. Nice to see some engineers thinking outside the box though.


#2

Wonder how that is going to work when trying to start the engine in cold weather.


#3

Glow plugs in a diesel work well, surprisingly well when you consider you are starting an oil with low volatility. Piece of cake with gasoline.


#4

I don’t think this is the right forum for new and innovative ideas.


#5

Just a question of good change versus bad change. Good change if it improves performance, reduces cost, moving parts etc. Bad change if it makes an engine cost $8000 instead of $5000, makes service difficult and expensive, and is unreliable. I had a diesel though and it started in Minnesota all but once. The rest of the experience was less than happy though.

I do remember way back in the 60’s? seeing the article on Chryslers turbine. Sure to be the engine of the future and runs on perfume even that happened to be more expensive than gas. I thought it was a neat idea back then.


#6
Just a question of good change versus bad change. Good change if it improves performance, reduces cost, moving parts etc. Bad change if it makes an engine cost $8000 instead of $5000, makes service difficult and expensive, and is unreliable.

Good point. But at this point it’s way too early to tell.


#7

Interesting concept and as per usual, the buying public will be the laboratory rats if and when offered.


#8
@Bing I do remember way back in the 60's? seeing the article on Chryslers turbine. Sure to be the engine of the future and runs on perfume even that happened to be more expensive than gas. I thought it was a neat idea back then.

Here’s what the article didn’t tell you.
Piston engines can be made to run on perfume also.
That turbine engine consumed 1.4 gallons per hour just sitting at a red light idling.

@dagosa

Glow plugs in a diesel work well, surprisingly well when you consider you are starting an oil with low volatility. Piece of cake with gasoline.

Diesel has a lower ignition temperature than gasoline does. So does motor oil. Spill oil on red hot headers and you have fire. Do the same with gasoline and it boils off often without igniting. When you see a race car blow an engine and catch on fire, that’s usually lube oil, not fuel that’s burning. That’s why diesel engines quit running when someone accidently fuels up with gasoline and why they run like crap if there is any gasoline at all mixed with the diesel.
On the other hand, diesel mixed with gasoline lowers the octane of the gas and will promote detonation in a spark ignition engine.


#9

Sounds somewhat similar to an engine Mazda is working on, though their engine does have a spark plug for when the engine needs to put out maximum power. Compression-ignition engines typically take a long time to burn the fuel dully, so the expansion cycle is long, as they noted in this article. This is good for maximum efficiency, but not for maximum horsepower. The Mazda engine is like this Hyundai engine in that it runs on compression ignition most of the time, but can switch to spark ignition when more power is needed, such as under acceleration. To me that combines the best of both engine types better than this Hyundai engine does. It is just a gasoline-powered diesel that achieves high enough pressure for ignition through clever shaping of the piston and direct injection. That"s interesting, but limited. It lets you run gasoline instead of diesel fuel, which is great, as diesel fuel is much more in demand, and more expensive.


#10

It’s an interesting concept. It’ll be interesting to see how it pans out. Could be another 5 or 10 years or more, but time will tell.

I did notice that the article said that the “lean mixture”, and, I suspect, the lower combustion temperatures, require a second catalytic “oxidizer” to reduce unburned hydrocarbons and carbon monoxide. It sounds like the balance will be delicate between optimum efficiency and low emissions.


#11

Have an acquaintence,who with some other very bright Guys are working increasing the effiecency of turbine engines(closer to piston engines all the time) despite the effiecency nod to piston engines,sometimes the math works in favor of turbines(consider how well they work in heliocopters and the “Abrams”-Kevin


#12

The reason turbines work so well in aircraft is that aircraft cover nearly the entire trip with the turbine running at 75 to 100% full power, the power range where they are efficient.
Turbines have always had a notoriously high idle and low power fuel consumption compared to piston engines of the same power and cars spend a lot of time with the engine idling or making very low power. In fact, car engines spend very little time at maximum or close to maximum power, even with Sammy Hagar at the wheel.

Aircraft are very weight sensitive and the low weight of a turbine usually more than offsets its somewhat lower efficiency. What good is an engine that’s 10% more efficient if it makes the plane so heavy that it takes 20% more power to fly it?


#13
Interesting concept and as per usual, the buying public will be the laboratory rats if and when offered.

Yup…that’s all it is right now is a concept. Interesting though. I always like out of the box ideas like this. Keeps technology moving forward.


#14

If combustion is initiated with high compression it is a diesel engine.

But then the Wright Brother’s Flyer engine had no spark plugs as I recall. And of course model airplane engines have glow plugs.


#15

I have a friend who was working (now retired) on this concept. Emissions will be an issue because the exhaust is quite cold compared to other gasoline engines. It is hard to light off the catalyst. The cold exhaust is a hint at the efficiency. The energy is being used to push the piston rather than sent out as hot exhaust. These two aren’t the first to explore the concept but I suspect they are farther along. Argonne National Labs have been looking into this as well as, I think, Ford.

It is an interesting concept to extend the reign of gasoline engine just a bit longer.


#16

this system increases power and fuel economy by atomizing the fuel off the piston at a much higher pressure opposed to doing it off the intake valve at a low pressure. which means more fuel is being burnt in the engine and not the catalytic converter. also because of the precision of direction injection much leaner fuel conditions can be achieved safely while cruising saving gas. .


#17

I have been curious as to why no one has made any efforts to develop direct injection 2 stroke technology for automobiles. All things considered, it seems to offer a great deal of potential.


#18

RK -“But then the Wright Brother’s Flyer engine had no spark plugs as I recall.”

Wow, you ARE old!

As for direct injection in 2 strokes, it’s being pursued:


#19

@Rod_Knox: “I have been curious as to why no one has made any efforts to develop direct injection 2 stroke technology for automobiles.”

I think the reason is that no two stroke engine could ever pass emissions. Deliberately burning oil in the fuel mix as a means of lubrication is a very dirty process.


#20

The Wright engine used a magneto and a mechanically operated sparking contact switch in each cylinder: