yes theres just something about animation/technical drawings that aid my understanding I could have something in my hand or be able to touch it and take it apart and I wont understand it as well as if i have a techinical drawing

 

yeah, same here.

 

i love the butt secks all star

 

And I love you too

 

total gheyness

 

Ecotec engines use sequential fire injection. Each injector is opened only when it's dedicated cylinder requires fuel.

I only mention this because MPFI is a generic term. Some MPFI systems used a batch fire setup that would open a group of injectors at once just to deliver fuel to one bank of cylinders.

SEFI is far superior.

 

Every Ecotec since the begining has had the same injector setup until the LNF (later). The injectors are mounted into the cylinder head and spray directly against the face of the intake valve.

(pic here later, I promise)

The heat of the intake valve helps to further atomize the fuel and promotes mixing before entering the combustions chamber. The injector does NOT fire only when the intake valve is open. An injector operating at 80% duty cycle is open for 576 degrees of crankshaft rotation. A typical intake valve is open for 210 degrees. The fuel simply mixes inside the intake port until the cylinder draws it in.

The LNF's direct injection is VERY different. First, as already discussed, it fires directly into the combustion chamber.



This injector fires during the intake stroke at a much higher flow rate then a typical injector. It has to deliver as much fuel in less time. Mixing occurs directly inside the chamber. One advantage of this is you can meter fuel into the chamber whether or not the intake valve is open.

Additionally, the injector will actually fire during the exhaust stroke when the engine is cold to warm the engine up faster for better emissions control.

 

Halfcent, What does LNF stand for? I've been racking my brain, but I don't think I have ever seen that acronym before.

 

It is not an acronym. Its the GM product code for the engine. There are a lot of Ecotec engines.

L61-The original 2.2L all aluminum Ecotec, created from the Saab design.
L42-The natural gas version of the L61
LSJ-The supercharged 2.0L
LE5-The 2.4L VVT engine
LNF-The 2.0L turbo
LK9-The Saab iron block turbo

There are others as well. Some are discontinued. I always talk in these terms to eliminate confusion between models.

In the current production models, they all share the same basic block design. They are in fact interchangable except for the LE5. It's kind of the bastard child. The only real difference between them all are their rotating asseblies (also interchangeable) and their heads (limited interchangability)