The internal combustion engine, for all its mechanical sophistication, still runs on a 19th-century mechanical idea: pistons rising and falling, a crankshaft spinning, a steam-age architecture ...

There are a lot of strange automotive designs out there, but this defunct engine from the '70s may just be the weirdest one ...

When it comes to unique engine designs, one of the most prolific is the trusty rotary configuration. Instead of featuring a number of spherical cylinders moving up and down like in most internal ...

Wankel rotary engine powered thousands of aircraft. One of several problems: It spewed castor oil on its pilots.