Radial engines may have been the better option during WW2 for military fighter planes, but nowadays, they are much more rare to find. Here's why.

May 7, 2012 7:28 PM EDT Start the Conversation . ... The craftsman has spent the last four years building a nine-cylinder radial engine using a smattering of Honda XR600 singles for his airboat.

However, a few automakers thought the radial engine would be equally at-home in a car. As you can imagine, the idea didn't catch on, but not before we got to see a few interesting attempts.

This time around, we’re diving into the man’s curious, crazy crankshaft-less 18-cylinder radial engine, which he dubbed the PowerRRing 3 Cycle.