okie..i got a question about the various ecotecs....namely, what makes them different?
im going to compare what i know to the L61..
LSJ is destroked to a 2.0 liter with some stronger internals
the 2.4 (idk what its called) is stroked to a 2.4 liter and has VVT
i dont have a clue on the LSF (turbo ecotec) but i think its destroked to a 2.0 as well

so what are the differences in the engines (be technical if you can) and are there any other ecotec variants?

 

The turbo ecotec has the RPO code LNF.

It's one of the most advanced engines in GM's line up.
LNF
=================
2.0 Litre
Twin Scroll Turbo
Direct Injection
Coil On Plug
VVT


LSJ
=================
2.0 Litre
5th Gen M62
Multi Port Sequential Port Fuel injection
Coil on plug

 

L61: 2.2L base engine platform
LSJ: 2.0L supercharged engine based on the L61 using a different rotating assembly to achieve the smaller displacement. Many parts are interchangable.
LE5: 2.4L VVT also based on the L61. It has a larger bore via different sleeves and completely unique cylinder head. Most parts are NOT interchangable.
LNF: 2.0L direct injected turbo engine, again based on the L61. The bottom is nearly identical to the LSJ. The cylinder head is again completely unique and not interchangable.
LK9: 2.0L Saab turbo. This is the current production design of the original Saab engineered Ecotec that GM basically stole when they bought Saab. It is very similar to the LSJ except it's turbo'ed instead of super'ed.

The L61 and LSJ and highly compatible parts wise.

 

hmm...thanks guys...new question
whats the difference between Multi Port Sequential Port Fuel injection and Direct Fuel injection

 

From my understanding...

Direct Injection is when the injectors are sprayed directly into the combustion chamber rather than going through the air intake stream.

 

is there any advantage to one or the other?
i suppose you can have the injector in direct injection fire in a way to make an even mix of air to fuel throughout the cylinder...but i cant imagine it would help that much..

 

Direct Injection would be more efficient because it's being mixed right as its being sprayed rather than having to go through your cylinder head.

 

DI is greatly superior in fact. You have much more direct control over the AFR. There is no fuel being sprayed at the face of the intake valve, so no deposits. No backfires, ever. You can inject fuel into the cylinder even when the intake valve is closed. You might think that's weird, but there are reasons.

Don't let all those fancy names you listed confuse you. Multi-port FI just means that there is a separate injector in each intake port of the head. DI is almost indentical. The only difference is where they locate the actual injector.

Read this thread;
The GM LNF engine

 

DI is superior, I agree. I've seen many people complain about cold starts with DI being noisy. Not a problem for most people, just throwing that out there.

 

bump for a good thread

 

w00t, i got bumped....okay, so multi port inject and direct inject are almost the same then? u lost me halfcent...started sayin DI is far superior, then saying "dont let the names confuse you (theyr epretty much the same)"

im gonna take a guess...
multiport injects right before the valve, and DI is directly in the chamber? if not...where?

 

And thanfully , GM uses a Wide band oxegen to sensor to fully benefit from Direct Injection and can target exact A/F's across the entire operating range , with correction factors to always maintain a desired ratio . I was really pleased to hear they used a Wide band .

The one thing thats very different though is DI is fed by a mechanical pump( in GM's case anyways) at 1200* psi . A normal injector only see's typically between 35-60 psi.

HunterKiller89 - The fuel injector is in the intake manifold aimed towards the intake valve in a tradtional set up . For DI , the injector is in the cylinder head spraying directly into the combusion chamber .

 

mk..so does multi port FI inject in the cylinder or the intake manifold? im basically tryin to ask whats the diff between multi port fuel injection and direct injection...if any

 

The multiport is mounted in the intake manifold in the intake runners and aimed toward the intake valve , the only way to get fuel into the combustion chamber is thru the open intake valve . The easiest generalazation to make about a DI injector , is like a spark plug ...its mounted to the cylinder head and the tip of the injector protrudes directly into the combusion chamber and sprays in fuel directly into the chamber .

Take a cannon ball for instance . Multiport would have a wick , u light it , it burns down ...then goes BOOM . With DI , no wick ...u light it and instant BOOM

 

gotcha
thnx man

 

Don't have any really helpful info, but I found some cool high-res LNF pics:

 

Here is what you do. Go look at your fuel injection rail on your own car. Take off that silly ass plastic cap on the top of your engine if you haven't already. The fuel rail is right there in the front. You can plainly see on the Ecotec how the injectors are mounted in the clyinder head just above where the intake manifold is mounted. The portion of the head that leads from outside the head to inside the combustion chamber is called a "Port". Its the same for both intake and exhaust. The fuel injector sprays gasoline into this area, just outside of the combustion chamber. It literally sprays the fuel on the outside of the intake valve, where is then waits for the valve to open and draw the mixture into the chamber.

With DI, the injector is still mounted in the head, but now its on the chamber side of the intake valve. So nothing separates the fuel from the chamber while it's being sprayed.

On one of those pictures above you can see the injector.

That's the actual fuel injector nozzle right there. On traditional FI engines, the nozzle is behind the intake valves, which are the two large circles on the left. As you can plainly see, you don't have to open those valves now in order to spray fuel into the chamber.