Nissan injects new life into petrol engines

[jpd80]

Nissan injects new life into petrol engines

LINK

Nissan is claiming a world first technology breakthrough that it says will significantly reduce fuel consumption in small-capacity petrol engines. The new Dual Injection System uses a fuel injector for each port in the cylinder, instead of the current single injector per cylinder supplying two intake ports.

 

According to Nissan, the new system reduces the amount of unburnt fuel and hydrocarbon emissions. The system works in conjunction with continuous valve timing control to improve fuel consumption by four per cent.

 

The Japanese company says the system is superior to direct injection on small capacity engines because it requires a less complex design. As a result, the company claims that it reduces build costs by 60 per cent.

"We consider it important to further improve the fuel efficiency of gasoline engines as demand for gasoline and other internal-combustion systems continues to increase around the world," says Shuichi Nishimura, Corporate Vice President, Nissan Powertrain Engineering Division.

 

"By widely applying the Dual Injector system on small-displacement engines, we hope to help reduce CO2 emissions and conserve rare metals."

 

Roll-out of the new technology will begin with the 2010 models using small capacity engines.

 

Be aware this article was sourced internationally and engines supplied to the USA may be different.

 

Could they be using open port injection at lower speeds to immitate the effect of Direct Injection?

I wonder if time will prove Nissan's gamble correct.

Edited July 16, 2009 by jpd80

[OHV 16V]

Be aware this article was sourced internationally and engines supplied to the USA may be different.

 

Could they be using open port injection at lower speeds to immitate the effect of Direct Injection?

I wonder if time will prove Nissan's gamble correct.

 

Good find jpd, I wonder what percentage of this also has to do with Nissan's recent slight downturn in their financial situation (meaning = a way to save having to incur the developmental costs of DI) versus using this method, which, as stated, is less complex by 60%?

 

I claim ignorance here, does Nissan already use DI in their small engines elsewhere in the world?

[jpd80]

Good find jpd, I wonder what percentage of this also has to do with Nissan's recent slight downturn in their financial situation (meaning = a way to save having to incur the developmental costs of DI) versus using this method, which, as stated, is less complex by 60%?

 

I claim ignorance here, does Nissan already use DI in their small engines elsewhere in the world?

I'm not sure whether they use Direct Injection on any of their engines, it sounds like they really

want to boost fuel economy with twin injectors rather than improve power.(not mentioned).

 

At the moment, I think the Dual Injection suits their ends in being economical to produce,

easy to roll out and a perfect marketing hook to buyers wanting something cheap and efficient..

[OHV 16V]

So probably a safe bet that when shows up on U.S. shores, look for it in Versa and Sentra advertising.

[old_fairmont_wagon]

Well, Nissan wants to avoid having to redevelope any more engines at the moment. As has been pointed out on here many times, for DI to really be a benifit, the engine (especially the heads and combustion chambers) has to be developed with it in mind. You can develop a smaller engine with a setup customized for DI and achieve the same power as a larger engine, but use the same fuel that the smaller engine would have used anyway. This also saves you some weight. Nissan doesn't want to invest in that at the moment.

 

DI is also expensive because it requires more expensive, more durable injectors (they are in the combustion chamber after all and carry much higher fuel pressures). The fuel pump and plumbing has to be more robust (again, higher pressures) and there's this matter of lots of IP tied up in those systems as well that makes them even more expensive to use. Nissan's system will be easier to retrofit to existing engines and really will only cost as much as an extra set of injectors as the extra plumbing will be negligible, the extra wiring will be negligible and the rest is software. Plus, the injectors will be smaller and of lower capacity since there are two of them to feed a cylinder now, making them a bit cheaper as well.

 

Fundamentally, two injectors will give you better fuel dispersion in the combustion chamber giving a better combustion of the charge. It still takes up intake volume, so that benefit of DI will be unavailable to them. However, a 4% gain is nothing to sneeze at. In an ideal arrangement, DI can maybe get you 8-10%, again, that's a bottom up rethink of the powerplant for the same power level as what you're comparing to. You start taking extra power and the fuel savings go out the window quickly. With a 60% cost savings as compared to a similar DI system, that 4% is very attractive. It has been speculated on here before that Ford would not use DI on their smaller EB engines.

 

And, as I have stated before, most of this is greatly simplified from the actual specifics of how the whole thing works, but it makes it more understandable and accessible to everyone reading here.

[OHV 16V]

As I've stated before Old Fairmont, I find your posts informative & I enjoy the reading. Very educational.

[lfeg]

QUestion. From reading this, it applies to engines with 2 intake valves per cylinder. Is this what you read?

If so, I can see an advantage to this, as it will give better mixing for a multi valve head. But, for small low output engines, are multiple valves always better?

[battyr]

Nissan is just being cheap. DI is still new for gasoline engines and will improve over time. I can see the cost savings of dual port injectors over direct injection. What it won't do is allow for increased compression, use of turbos with either high compression or over boosting, increased compression with regular gas and lean burn.

[battyr]

QUestion. From reading this, it applies to engines with 2 intake valves per cylinder. Is this what you read?

If so, I can see an advantage to this, as it will give better mixing for a multi valve head. But, for small low output engines, are multiple valves always better?

 

I would think multiple valves are standard on small engines in Europe and Japan. I read "low output engines" as meaning no turbos and no VVT.

[CivicDuty2007]

Nissan must have studied BRP's(Bombardier Recreational Products) book on fuel delivery....

 

In their snowmobiles, they have used the same technology for years, they called it "SDI" or Semi-Direct Injection, where they used an injector in each throttle body and another two injectors in the base of the engine, near the ports. Lately, they have been starting to use direct injection directly into each cylinder(minus the throttle body injector), borrowed from the line of Evinrude and Johnson outboards that they produce, this one is called "E-Tec".

[Hemiman]

Nissan must have studied BRP's(Bombardier Recreational Products) book on fuel delivery....

 

In their snowmobiles, they have used the same technology for years, they called it "SDI" or Semi-Direct Injection, where they used an injector in each throttle body and another two injectors in the base of the engine, near the ports. Lately, they have been starting to use direct injection directly into each cylinder(minus the throttle body injector), borrowed from the line of Evinrude and Johnson outboards that they produce, this one is called "E-Tec".

 

 

Or, maybe they looked at the LT5 engine that GM had back in the early 90's.

[jpd80]

Or, maybe they looked at the LT5 engine that GM had back in the early 90's.

I'm sure it's linked to Open port Injection, something GM and Ford dabbled in but found

it had problems with with emissions. Perhaps that problem only exists with larger engines

and smaller engines slip through the cracks.....

Edited July 16, 2009 by jpd80

[J-150]

isn't this like the OHV vs OHC argument?

 

 

GM and Chrapsler have been chided for OHV engine designs as being old and archaic. But those engines are still quite potent and can compete to some degree with similar OHC engines.

 

to-may-to or to-mah-to

[the_spaniard]

As I've stated before Old Fairmont, I find your posts informative & I enjoy the reading. Very educational.

 

+1, Thanks for educating the savages.

Edited July 18, 2009 by the_spaniard

[theoldwizard]

Lately, they have been starting to use direct injection directly into each cylinder(minus the throttle body injector), borrowed from the line of Evinrude and Johnson outboards that they produce, this one is called "E-Tec".

A more cost effective solution than the DI system that Ford is using. No high pressure pump.

[RichardJensen]

A more cost effective solution than the DI system that Ford is using. No high pressure pump.

But how much more cost effective?

 

If you're getting a 4% improvement in FE as opposed to an 8% improvement (from DI), you're getting half the FE gains for 2/5ths of the cost--which is a savings, but not much of one. If you get a 10% improvement from DI, you're looking at a wash in terms of cost savings vs. FE

 

(Assuming that the 60% savings is for the cost of the fuel system, not the entire engine)

 

I notice that they are not making any claims regarding HP/torque, nor any claims about emissions.

 

So that raises the question--is it really a savings if you get negligible improvement in the other two important metrics of engine performance (emissions & power).

Edited July 21, 2009 by RichardJensen

[jpd80]

But how much more cost effective?

 

If you're getting a 4% improvement in FE as opposed to an 8% improvement (from DI), you're getting half the FE gains for 2/5ths of the cost--which is a savings, but not much of one. If you get a 10% improvement from DI, you're looking at a wash in terms of cost savings vs. FE

 

(Assuming that the 60% savings is for the cost of the fuel system, not the entire engine)

 

I notice that they are not making any claims regarding HP/torque, nor any claims about emissions.

 

So that raises the question--is it really a savings if you get negligible improvement in the other two important metrics of engine performance (emissions & power).

Could they be looking at two situations:

Existing 1.6 => 1.6 Dual PFI = increased fuel economy (4%)

Existing 1.6 => 2.0 Dual PFI = similar fuel economy, increased torque and HP over existing 1.6

 

I think I see what they're trying to do, it looks like a cheaper solution but does the math hold up?