What are the advantages of using an engine with less stroke compared to one with more stroke for the same displacement?

Bore and stroke establish an engine’s displacement, but their relationship to each other also affects the engine’s operating characteristics. This is sometimes called the stroke ratio.

In general, an oversquare bore, which is an engine where the bore diameter is greater than the length of the stroke, will rev higher, and is capable of producing more horsepower, but with lower torque.

An undersquare bore, where the stroke is longer than the diameter of the bore, normally produces less peak horsepower, but more torque at lower RPM’s.

An example of an oversquare engine, which has a relatively large bore, but short stroke is the Ford 289 V8. It’s known for its exceptional ability to rev quickly and produce good horsepower at higher RPM’s.

An example of an undersquare engine, which has a longer stroke and smaller bore is the Chrysler Slant 6, which produces relatively small horsepower numbers, but comparatively high torque numbers at low RPM’s.