Crazy idea?

Frederic Breitwieser frederic.breitwieser at xephic.dynip.com
Fri Mar 20 14:27:35 GMT 1998


>Hi everybody.   I just joined, have some FI experience, but I'm NOT an EE
>(in other words, I'm easily lost in circuitry)

That's okay, I for one have lots of electronic experience, but am lost in
fuel injection (I know what gasoline smells like <G>)

>I know there are problems with injector mis-timing due to acceleration /
>deceleration, but it's got to be better than firing them all at once.

I think what you are proposing makes a lot of sense - however there is
something to consider aside from timing - is the injector size.

Bear with me here... I'm thinking aloud, and not basing it on "real
knowledge" per se...

Your engine fires three cyl's per rotation, standard four stroke.

That means every time the intake valve opens, you have six pulses worth of
fuel resting on the valve, which I will call X milliliters.

In order to achieve the "X" you'd have to drastically increase the
pulsewidth, increase the fuel pressure on the rail, run larger injectors,
or a combination of all three.  This gets a little complex for me, but you
need to achieve the volumetric equivilent of the six injector pulses "X"
with your one firing of the injector.

Increasing the pulse width will be less effective at higher RPMs, as their
could be some overlap, and unless your system started firing injectors
early for higher RPMs, you'll get a fraction of the "X" into the cylinder.
This makes things more complex, which it sounds as though you are
attempting to avoid.

Though on the flip side, you might be able to use injectors from a
sequential injector car (late 80's GM 6 cyls or early 90's Ford/Lincoln
cars for example, many others fall into this catagory), with a "standard"
fuel pressure of about 45PSI on the fuel rail, you'd be achieving the same
gasoline presence as more modern engines.  Of course, getting injectors
from a car similar in displacement +/- 5% would be about right...

Keep us informed with your progress, I'm curious to see how you make out.
What year Bronco BTW?  I used to have a 1979, and always liked them,
dispite the lack of ability to adjust camber :(


Frederic Breitwieser
Bridgeport, CT 06606

Homebrew Automotive Website:
http://www.xephic.dynip.com/

1993 Supercharged Lincoln Continental
1989 HMMWV
2000 Buick-Powered Mid-Engined Sports Car




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