equations for inj. flow rate for small engine

[Greg Hermann]

>I'm looking into efi-ing an onan 2-cylinder (about 18hp) 4-stroke gas
>engine.  Not a throttle body injection, but port (its easier to mount
>the injectors on the intake than to make a TBI with injectors.  What
>is the math that needs to be done to calculate the injector size?  How
>about TBI flow rate or diameter?  Thanks a bunch!
>
>Andy Quaas
>
18 HP/2 cylinders= 9HP/ cyl.

Assume BSFC of .55 lbs of fuel/BHP hr. (small engines are pretty inefficient)

Multiplication means you are looking for about 5 lbs/hr. injectors (if you
can find anything that small.) Bigger (up to maybe 10 or 12 lbs / hr.)
would probably work OK for idling on something like this, but try to get
the smallest injectors you can find.  (For furrin ones, 10 cc/sec is
roughly equal to 1 lb./hr.)

Regards, Greg