Origin of 'Straight 8' name

[Chuck Guzis]

Back in the first half the 20th century, there were various
configurations of 8-cylinder internal combustion engines.

We're all familiar with the V-8, but there were inline 8-cylinder
designs used primarily on luxury cars, making for a wonderfully long
engine compartment.  Cord, Buick, Packard, Chrysler and Oldsmobile all
offered the "straight 8" on their high-end models.  Those were called
"straight-eights", I suspect because of the attractiveness of rhyming
name. "Straight 8" configuration was also used on some aircraft as well.

I suspect the name for the early PDP-8 is just a convenient adaptation
of a once well-known automotive term, much like "V-8".

For what it's worth, Ford experimented with an X-8 configuration as
well, but never put it into production.

--Chuck