THERE IS NO REASON in the wide wide world of sports that you should have to mount the electric exactly inline with the engine pump. And you ought'ha have a shroud on there
If you cannot do anything else, measure, with fan "back" as far as you can, and off to one side as far as you can, and have / or fabricate a sheet metal shroud and mount the fan on the shroud. "You may" have to build some floppy rubber / hinged "check valves" on the other side to allow free flow of air through there at speed
