I did think of a system along those lines,where a single solenoid opens and feeds 8 nozzles, each having a spring loaded non return valve. After pondering for a while I decided it wouldn't work very well at low engine speeds and idling. The quantity of fuel at these times would be miniscule and possibly even the flexibility in the feed line sidewalls would absorb the fuel pulse, rather than the valve actually opening.
Even if the spring valves did open then the chances of them opening at the same time/rate would be virtually zero.
My current thinking is to keep the solenoid as big as I can, to negate the effects of scale as much as possible.
This means using just one or 2 injectors, hidden away inside a plenum chamber, like my full sized motor.
They would have to spray fuel just behind the throttle body at the front, hopefully keeping the fuel atomised as it gets sucked in.
8 injectors would be great but the more I think about it, the less realistic it looks.
Thanks for replies so far.