Multiprocessor system

dn dn at dlogtech.cuc.ab.ca
Sun Feb 11 20:43:50 GMT 1996


Me:

> >Pardon my ignorance here, but what the heck do you need more than 1 output
> >compare for?  You only have 1 cylinder firing at a time 

Peter:
 
> Wrong. At WOT (I'm fed up with yanks pussy footing it around. Get your foot
> down :), All of the injectors can be open at the same time.

Whoa, now I'm really confused....  

I know I'm not wrong about firing 1 cylinder at at time, last time I 
looked in my HEI there were 8 little posts and only 1 contact on the
rotor...

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...

With a TBI setup, I can see this happening, or on a system with less than
an injector-per-cylinder, but not on a port injection setup... but then
I've also been wrong before (once or twice).  Enlighten me, oh guru.

regards
dn

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 Darrell A. Norquay              Internet: dn at dlogtech.cuc.ab.ca     
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