I talked to then many years ago as I was thinking about one but the only one they offered had a 1.5 inch bore and that just ain't going to flow enough air for the rotary so you would need two of them at double the cost.
  Ken Welter


I don't know what they offered many years ago, but they now list models from 30-350 HP.  On my O-360, I had an EFS-4-5, which is rated for 180-225 HP.  I'm thinking that would be the size I'd want for a 13B as well.

http://www.ellison-fluid-systems.com/products/injectors.htm

Rusty (looking for ways to simplify my life)