in 1933, the SS50 Super Scarab was a higher output version of
the original Scarab with the cylinder bore increased to 4.625
inches. The U.S. military designation for the SS50 was the R-500.
|Radial piston engine|
|Displacement: 499 cubic inches (8.2 liters)|
|Bore x stroke: 4 5/8 x 4 1/4 inches|