Direct injection vs fuel injected engines

[chittybangbang]

Whats makes a direct injection any different from being fuel injected.Just curious.

 

[Jason]

Fuel is shot in to the combustion chamber and gets no chance to pool and drip out of an intake manifold. The fuel is spread out further and more evenly in the chamber giving better combustion.

Plus, it's a bit lighter.

 

[triumphrider-1]

Direct injection sprays the fuel directly into the combustion chamber as shown below:

Where as standard fuel injection sprays the fuel in the intake runner, usually really close to or onto the intake valve(s):

 

[shadetree]

Direct injection is where the fuel charge is injected directly into the combustion chamber. Diesels use direct injection. This form of injection is being looked at for use in automobiles. I think some motorcycles may use it now.

EFI, electronic fuel injection the fuel is injected into the air stream before the intake valve. This form is usually "bank fired" in that all the injectors on one bank fire at the same time.

Sequential Fuel Injection, SFI, the fuel is also injected before the intake valve, but each cylinder fires independently as opposed to bank firing. Most of todays engines are SFI.

Throttle Body Injection, TBI, works similar to a carburetor. The fuel is injected at the throttle body base, and mixed with the incoming air at this point.

There is also mechanical fuel injection in which the fuel is injected at the intake valve. This is used mostly in racing applications.shady

 

[triumphrider-1]

EFI, electronic fuel injection the fuel is injected into the air stream before the intake valve. This form is usually "bank fired" in that all the injectors on one bank fire at the same time.
shady

I would more consider this port fuel injection, with EFI more a blanket term for all electronic injection systems.

 

[mentalbreakdown00]

also to note: DI systems use a throttle plate for idle only for right now and may be eliminated here soon if i remember right. Also the mixture can be overal a lot leaner in the combustion chamber with a small pocket of 14:1 near the plug for better emissions/ economy. Also no electric pump can withstand the pressures needed for this system, and as of now are usually belt or gear driven.

 

[85_Ranger4x4]

Direct injection is where the fuel charge is injected directly into the combustion chamber. Diesels use direct injection. This form of injection is being looked at for use in automobiles. I think some motorcycles may use it now.

Not all diesels are direct injected, there are quite a few IDI diesels still floating around.

There are a couple direct injected gas car engines out already. Ford's new upcoming "Ecoboost" linup is direct injected too.

 

[chittybangbang]

Not all diesels are direct injected, there are quite a few IDI diesels still floating around.

There are a couple direct injected gas car engines out already. Ford's new upcoming "Ecoboost" linup is direct injected too.

I knew the diesels were DI .But yeah,I've been reading that GM and Ford have or are coming out with DI gas motors.

Is this the next best thing to happen to gas motors? I have a vtech/cylinder deactivate mgmt engine in my Honda and IMHO the cylinder deactivation is snake oil.

 

[AllanD]

Basically Gasoline Direct Injection allows for a more efficient "diesel cycle" operation on gasoline.

while some people like to claim Diesel fuel has more energy per unit (which it does)
reality is rarely that simple, and in this case it isn't... because even under ideal circumstances diesel can't burn as FAST as gasoline does, which requires diesel
engines to be built "under square"

the issue with gasoline engines and the diesel cycle has always been that
to run them leaner than about 14:1 results in melting things.

but using an injected mix of fuel and air in the "core" of the combustion chamber
surrounded by a curtain of air that protects the piston crown and chamber walls from the higher heat (the combustion temp of gasoline in air peaks at ~17.5:1)

so in part throttle operation they can make them amazingly economical.

An engine that will produce MORE power relative to displacement than previously possible
Produce FAR more torque than an oil burner twice it's size... there's basically nothing to not like.

That plus the engine with proper sensors to detect the fuel will run on anything from
Jet Fuel to Acetone and everything in between including heavy alcohols like Butanol...

AD

 

[TRX501RYAN]

Another bonus for DI is the fact you can also run higher compression ratio's in the motor with out pre detonation, because the fuel is injected specifically when it needs it, basicly giving it less time to have pre ignition,

 

[Captain Ledd]

Not all diesels are direct injected, there are quite a few IDI diesels still floating around.

IDI is still injected directly into the cylinder, the difference being there is a special chamber it's injected into first (which is open to the main combustion chamber) which helps ignite the fuel in a way that it enters the actual combustion chamber much more smoothly and evenly (it's a very small chamber). Mostly this was a noise reduction issue and predominantly used in passenger cars, or just where people didn't want to hear diesel rattling. Modern Direct Injection diesels have gotten much better at controlling NVH levels using DI, and no longer need IDI to quiet things down. DI is supposedly slightly more fuel efficient as well.

 

[Broaner]

Nissan has been doing this on JDM production cars for some time(nearly a decade already IIRC). Note: JDM = Japanese Domestic Spec Not some fanboy term used by the fag in his civic that incesantly wants to race something. Specifically the VQ30 engines found in JDM Maxima's(Cedrics) and Altima's. But due to some regulations I'd imagine they haven't been allowed to bring it here. The engines that utilize this technology make at least 5+% more power and get significantly better economy than their USDM counterparts.

 

[85_Ranger4x4]

IDI is still injected directly into the cylinder, the difference being there is a special chamber it's injected into first (which is open to the main combustion chamber) which helps ignite the fuel in a way that it enters the actual combustion chamber much more smoothly and evenly (it's a very small chamber). Mostly this was a noise reduction issue and predominantly used in passenger cars, or just where people didn't want to hear diesel rattling. Modern Direct Injection diesels have gotten much better at controlling NVH levels using DI, and no longer need IDI to quiet things down. DI is supposedly slightly more fuel efficient as well.

Indirect injection into a precombustion chamber still isn't directly injected into the combustion chamber.

 

[Captain Ledd]

Indirect injection into a precombustion chamber still isn't directly injected into the combustion chamber.

They're permanently open to eachother. They just call it a precombustion chamber because it evens out the flame front for the larger one that the piston is in. There's nothing but an invisible line dictating the separation of the spaces.

But seeing as your avatar is what looks to be a diesel engine I'm guessing you're an expert/experienced diesel mechanic trying to clear up some something that's only "technicality" not direct injection.

 

[LearjetMinako]

I'm tired so I'll just post pics of the Ford's Ecoboost cut-away.