fuel evaporation & injectors

[jb24 at chrysler.com]

>>>>
>This reminds me, what's the deal with Mitsubishi's GDI (gasoline direct
>injection?) engines?  Is this a diesel type setup? I can't get
anything but
>Mitsu's hype about more power, less emissions, more mileage.

Basically, they eliminate the "swirl" problems around the valve when the
fuel/air mixes, and the fuel is injected directly into the cylinder,
supposively to atomize it much better.  Maybe, maybe not.  I can't
really
tell, but what they are doing is running the engines increadibly lean
during non-load periods (coasting, downhill, idle, etc) on alternating
cylinders, so there is enough "ooomth" to rotate the crank, but doesn't
really blow a lot of fuel.  This is how they achieve their high-mileage
claim, at least according to the documentation.
<<<<

Direct fuel injection for gas does a couple of things: allows extremely
lean combustion, beyond what is normally ignitable and allows for
elimination of part-throttle pumping losses by operating like a diesel
during lean combustion (i.e. wide open throttle, no throttling at
partial power).  One other benefit is near elimination of acceleration
enrichment.  The lean combustion is accomplished by stratified charging
the cylinder in the compression stroke by injecting late near the spark
plug.  The greater power claims are potentially explained by injecting
downstream of the intake valve, thus not displacing any air with
gasoline on intake (although only marginally).

John Bucknell is jb24 at chrysler.com