Multiprocessor system

[Jim Sturcbecher]

<snip>

>Your'e telling me that in a V8 port injection system, all 8 injectors 
>can be open at the same time?  How is this possible?  Only 1 cylinder 
>is at TDC on the power stroke at a time, therefore previous to that 
>it's intake valve will be the only one open.  Cylinders in the firing
>order are separated by 90 degrees of crank rotation.  Taking into 
>consideration that the injector can open before the valve, it is possible 
>that 2 consecutive cylinders in the firing order could overlap somewhat 
>on injector opening, but all 8?  You'd just be dumping fuel into a port 
>with no flow, which seems to me would be counterproductive to vaporization...
>
>Also, the injectors are supposed to be sized to deliver enough fuel at
>around 80% duty cycle for WOT, you can't just turn on an injector and 
>leave it on or it dies a fiery death...
>

let me see...

On a V8 pulling 6000 rpm, that's 100 revs/sec. That gives 10 millisecs
per rev. If I want to inject all 8 cyls in 2 revolutions (this is a four
stroke after all), then thats 4 cyls per rev. Now if I don't want to 
inject more than one cylinder simultaneously, that gives me 2.5 millisecs
per injection event. I don't think any injector would be happy at that.
If you sized the injectors to give enough fuel in 2.5 millisecs, then
you would never get it to accept a short enough pulse to give a decent
idle.

Is my reasoning correct here?

Jim Sturcbecher
jsturs at bart.nl