i dont know about the bug engines but i had a 62 chevy corvair, very similiar to bugs, rear mounted air cooled but instead of 4 cyl horizontal engine they were six's twin carbs with a big turbine laying flat over the block to ram the aire thru the cooling fins, and exiting on each side out the rear, like dual exhaust, i swooshed across a end of a pond one time and with the throttle wide open it pushed enough air to push me right on across
