2 stroke injection experiences?

[RABBITT_Andrew at mv8.orbeng.com.au]

>Anyone on the list have experience of single or multi cylinder 2 
>stroke injection form a practical point of view?

we do fuel injected 2-s here for a living, DI though!

>Problems that arise on the theoretical level are passing an oil / 
>fuel mix (viscosity?) through a standard injector

most EFI 2-strokes use a separate oil pump (mostly Mikuni), injecting 
the oil upstream of the inlet reeds.  Check out the EFI outboards for 
some ideas.

>and monitoring an oily exhaust with a lamda sensor.

a two stroke will have an apparently lean exhaust due to scavenging 
losses.  Even if the inlet charge is 14.7, the exhaust will have a 
high oxygen content due to the 20+% scavenging losses out the exhaust, 
therefore a conventional switching type EGO will not be much use to 
you.

>Finally,where to inject,on both rotary valved and reed valved 
>engines?

Not real sure here, but I think normally just down stream of the 
throttle blade.  You may be able to reduce scavenging losses by timing 
the injection into the transfer ports, but without a heap of 
development it could be a bit hit-and-miss.  (note that lower losses 
means better fuel consumption, means less fuel mass for the same race. 
Could (partially) overcome any weight penalty.)

Andrew Rabbitt
Orbital Engine Company (but the opinions are mine)