Those planning an inverted system need to include a breather pipe of about 3/4" dia. running down one side of the fuselage, usually on the right, to the tail with an exit somewhere near the tail spring. It should pass through the firewall with a flange fitting. It should be very slightly down hill toward the tail. Not much, because it has to vent when inverted as well. Just a degree or two is enough. This will keep the airplane much cleaner.
Edited by: Neil
