Early Detroit Diesel engines, as used in Budd RDC's, PFE mechanical reefers, and over the road trucks, were also of a 2 stroke design, and used a mechanical supercharger in the valley of the V - Type engines. In the 1950's the Drag Racing crowd adapted the blower off a 6 - 71 Detroit Diesel ( 6 cylinders - 71 cubic inches per cylinder = 426 Cubic Inches ) to various automotive V-8 gas engines. One of the more successful engines was a 6 - 71 blower on a early Chrysler 392 C.I.D. Hemi. More recent blowers are purpose designed & built with screw - type impellers for quicker reaction and more volume, and gear drive replacing the older belt drives.