NISSAN HAS ANNOUNCED details of its all-new Dual Injector technology designed to improve fuel efficiency in small-displacement petrol engines.
The first of its kind for mass-production in vehicle engines, the new fuel delivery system speeds up fuel vaporisation by using an injector for each port rather than one per cylinder. The result is a reduction in unburned fuel and hydrocarbon emissions.
Unlike direct injection systems which require a high-pressure fuel pump (complicating system design in small-capacity engines and increasing cost), Nissan’s “structurally simpler” Dual Injection technology delivers fuel at normal pressures, “reducing cost by about 60 percent compared to direct-injection engines of similar displacement”, Nissan claims.
Where most petrol engines feature one injector per cylinder, Nissan’s Dual Injector system uses two (one for each intake valve port), resulting in smoother, more stable combustion.
The Dual Injection system also features continuous valve timing control on the exhaust side and conventional intake cam control, offering improved heat efficiency, reduced pumping losses and raising fuel efficiency by up to four percent when used in sync with the dual injectors.
“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,” said 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.”
Nissan says that its system is unique in that, unlike direct injection systems which require a high-pressure fuel pump (thus complicating the design of small-capacity engines), the Dual Injection technology only needs fuel at normal pressures.
Thanks to its lighter and structurally simpler design, Nissan’s Dual Injection system can also be produced at a lower cost - around 60 percent cheaper than an equivalent Direct Injection system - and uses half the amount of precious metals (such as platinum) in the catalytic converter compared to a standard engine.
The first production use of the Dual Injection system is scheduled for 2010, but Nissan has yet to confirm which models will see the technology first.
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I can’t see the point in this - direct injection is better still, and available now.
GP, the article suggests that this technology is better than direct injection - i.e. lighter, more fuel efficient, cheaper. These all seem like plus points to me.
I’m not having a go at you, I’d just like to know why you think direct injection is better? Yes, that technology is available now, but that’s innovation and progress for you. We (as humans) strive for progress. If we didn’t we’d still be driving around in Model T’s.
I got from the article that its not as good as direct injection, but its a good compromise between expensive DI tech and standard injection (it doesn’t say anywhere its better than DI other than its 60% cheaper). Needing less platinum in the catalytic convertor indicates that less unburnt fuel escapes the cylinders, so it would be more economical and cleaner than standard injection. Still, plenty of room in the market for a solution thats nearly as good yet much cheaper.
“The first of its kind for mass-production in vehicle engines, the new fuel delivery system speeds up fuel vaporisation by using an injector for each port rather than one per cylinder. The result is a reduction in unburned fuel and hydrocarbon emissions.”
This means that it is more efficient (for smaller displacement engines). This in-turn means that it is better than direct injection. Generally when technologies are more efficient, the outcome is more power and less waste. The fact that it is cheaper and less complicated is even better.
Sorry Brad no it doesn’t. You can not get from that paragraph that this system is better than DI. Its like saying ‘Jo is older than Steve and Dan is older than Steve therefore Jo is older than Dan’. Read Nissans release, they are comparing their system to standard injection where the injector injects fuel into the intake charge before it enters the cylinders. DI injects directly into the cylinders, cooling the combustion chamber making combustion more efficient. Nissans’ system simply uses one injector per intake port instead of one per cylinder intake, meaning it can atomise the fuel more, with the resultant benefits for fuel combustion and emissions. Nissans system is great because it offers a way to improve efficiency and emissions over standard injection without the cost of going full direct injection.
The point I was trying to make is that DI is available now, so why spend many research dollars building a “halfway house” injection system that is not as good (even though it’s better than one injector into two ports). However, you have to use twice as many injectors, which increases costs.
DI has superior abilities as well - it can inject at different times of the piston stroke and inject twice during cold cycle to reduce emissions.
However, one area where any throttle body/port injection system will always be better than DI is in keeping the inlet ports and valve stems clean. DI obviously cannot do that, so maintenance is required much sooner in that area.
I suspect, GP, that the point for Nissan is that it’s a simpler system to build into small-capacity engines than it would be in the case of direct injection.