Re: Some details of the 2AZ-FE engine

On Mon, 21 Jul 2008 06:35:30 -0700 (PDT), EdV <systmengr@[EMAIL PROTECTED]
>
wrote:

>On Jul 18, 2:16 pm, Retired VIP <jackj.extradots....@[EMAIL PROTECTED]
>
>wrote:
>> On Fri, 18 Jul 2008 08:36:01 -0700 (PDT), EdV <systme...@[EMAIL PROTECTED]
>
>> wrote:
>>
>> >On Jul 18, 11:05 am, "C. E. White" <cewhi...@[EMAIL PROTECTED]
>
>> >wrote:
>> > There is an injector in the combustion chamber
>> 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
>
>Great! So this means its possible not to have VVTi and Direct
>injection at the same time. The timing of the fuel comes from the
>nozzle and not from the opening of the valves, although air enters
>through the valves, its the fuel which is controlled and not the air.

No, I think it would still be possible to use variable valve timing
and direct injection at the same time.  The amount of fuel is
controlled by the engine computer based on info it gets from the O2
sensor, throttle position, RPM, etc.  VVTi would still be a valid way
to increase engine efficiency by controlling the amount of air, that's
really all it controls with multi-****t injection also.

Jack