EAA Experimenter 11
BIG BORE ROTAX IS the nickname for Rotax 912
series engines that have been modifi ed to pro-
duce more horsepower with larger cylinders
and pistons using an aftermarket kit called the
Zipper 1484. Hal Stockman of Elko, Nevada,
the person behind the upgrade kit, brought his
RANS S-7S Courier that he calls the Super-7S
to EAA AirVenture Oshkosh 2014, where it
was displayed and fl own from the ultralight/
lightplane runway. The S-7S was built espe-
cially for short takeof and landing (STOL)
performance. The engine had 200 hours on
the new cylinders and pistons when Hal
arrived in Oshkosh after the 1,400-mile fl ight
from Nevada, and he had logged 320 hours by
the end of 2014.