The very general average is roughly 2hp per cfm. I say very general because I know of many engines that exceed that number by a bit, and a bunch that never reach it. It's hard to say because the bench results you are using are fairly subjective anyway. A good bench with "stingy" numbers may lead you to think you're making more power with less, and a generous bench may lead you beleive you are not making what you should.
Well, art is art, isn't it? Still, on the other hand, water is water! And east is east and west is west and if you take cranberries and stew them like applesauce they taste much more like prunes than rhubarb does. Now, uh... Now you tell me what you know.
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