injector manifold design

[Gary Derian]

Even with a short duty cycle, the injection event will stretch out at high
rpm.  The intake valve for 2 opens just before intake valve one closes.
This means some reversion from 2 goes directly into 1.  At least with a
carb, the fuel goes where the air does, sort of.  With injection, any
puddled fuel injected while both valves are closed will get atomized by the
reversion and sucked into 1.  2 gets no benefit from this and will run much
leaner.  Somehow fuel will have to be injected where it will remain near
intake valve 2 while 1 is intaking but not get blown into 1 when intake 2
opens.  I can't think of a good way to do this.  Has anyone else injected
this engine.  Maybe the mixture distribution is not as bad as it seems.

Gary Derian <gderian at oh.verio.com>

> Looking at one of your ports, the firing order is something like
> 1-gap-gap-2-1-gap-gap-2.......
> Now if you are squirting fuel at 80% duty cycle, what is going to stop
> cylinder 2 from sucking in some of the fuel which was intended for
cylinder 1?
>
> You could go for a sort of modified-sequential injection, but you would
> then be limited to a 25% maximum duty cycle per cylinder, which would
> require timed injection, large injectors, and difficult idle control, not
> to mention custom ECU software.
>
> regards,
> Mike
>