This is perhaps the smallest Diesel radial engine in the world, with a bore of only 5mm and a stroke of 5mm; total displacement of .49ccm. It was designed and built by Ronald Valentine in 2007.

It is machined from aluminum bar stock, has a 3-piece crankshaft, a central reed valve that is geared, and each cylinder has two intake and two exhaust ports. It weighs about 2.5 ounces and will run 9,300 revolutions per minute.

A 5-cylinder Diesel radial engine.
The 5-cylinder Diesel can fit in the palm of a hand.

Exhibit added: August 1, 2011 - Last modified: February 2, 2023

Presented by The Joe Martin Foundation for Exceptional Craftsmanship