Continental Motors O-470-B Operator's Manual page 96

VOU:METRIC EFFICIENCY -The ability of an engine
10
fill its
cylinders with air compared to their capacity for air under static
conditions. A "normally aspirated" engine will always
han~
a
yolumetric efficiency of slightly less than 100%. whereas super-
chargers permit volumetric efficiencies in excess of 100%.
11-6