Please note that this car is fitted with reproduction coachwork.

On 14 June 1923, Packard Motor Car Company introduced the Single Eight as a successor to the long-running Twin Six V-12.

At 357.8 cubic inches, it displaced some 15 percent fewer than the big flagship powerplant, but produced 95 percent of its horsepower.

More important than that, however, was its design.

A seminal breakthrough with its two-plane crankshaft, it set the pattern for all straight eights from that time onward.

Earlier inline eights were essentially two four-cylinder engines mated end-to-end.

Inherent to this design is a “secondary imbalance” caused by two of the pistons always moving together.

This creates a rocking motion at idle and roughness at high rpm.

By turning a portion of a flat-plane crankshaft, that for the four middle cylinders, 90 degrees, Packard engineers made the Single Eight smooth and silent.

The result was so successful that from 1925 the designation “Packard Eight” was sufficient....