Re: Some details of the 2AZ-FE engine

On Fri, 18 Jul 2008 08:36:01 -0700 (PDT), EdV <systmengr@[EMAIL PROTECTED]
>
wrote:

>On Jul 18, 11:05 am, "C. E. White" <cewhi...@[EMAIL PROTECTED]
>
>wrote:
> There is an injector in the combustion chamber
>> instead of in the intake tract before the intake valves. Air is
>> admitted into the combustion chamber by the valves. Fuel is injected
>> directly into the combustion chamber, instead of being mixed with the
>> air in the intake tract before the intake valves.
>
>Ahh, so the intake valves is just for the AIR and the injector for the
>FUEL. no pre-mixing involved. The mixing occurs directly inside the
>combustion chamber. The fuel is pressurized and not the air like in a
>turbo setup. Thanks!

Yep, you got it Edv.  But the fuel is injected into the combustion
chamber, not the intake manifold.

Of the three types of fuel injection, the direct injection has the
capability of being the most efficient.  The air/fuel mixture can be
precisely adjusted for each individual cylinder and for each
individual power stroke.

Throttle body injection is the least precise of the three.  It is
basically just a computer controlled carb that uses a injection jet
instead of a metering jet.  It's better than a carburetor but not by
much.

Multi-****t injection places one injector in the manifold runner to
each cylinder.  This is a better scheme that allows more precision but
it is limited on how much the mixture can be leaned out before
pre-ignition occurs.

Direct injection allows placing a rich fuel/air mixture around the
sparkplug and a much leaner mixture in the rest of the cylinder.  By
the time the flame front moves out to the rest of the cylinder, the
piston has moved past top dead center and the much faster burn rate of
a lean mixture won't hurt the engine.

I hope this helps and if I've gotten anything wrong in this, I'm sure
someone will correct me.

Jack