This 1/12 scale “Micro Cirrus” engine was designed by Merrit Zimmerman in 1974, and then manufactured by Profi M.E. in Ukraine. (The 4-cylinder version is also a part of Paul and Paula Knapp’s engine collection.) It runs on methanol with glow ignition and is among the smallest multi-cylinder 4-cycle engines in the world. The custom glow plugs are only a 5mm hex with a 3.5mm thread. The air-cooled engine is less than 4 inches long and has a mere .5cc displacement in each cylinder, making the 4-cylinder only 2cc and the V8 only 4cc total displacement. Initial test results proved these micro engines would spin their 7- and 8-inch propellers to 13,000 revolutions per minute.

Only 25 of the 1/12-scale 4-cylinder air-cooled engines were produced in 2001, and another 25 of a water-cooled version. In 2003, the remaining parts for the 4-cylinder engines were used to manufacture less than a half dozen each of the air-cooled and water-cooled V8 engines.

Exhibit added: May 1, 2008 - Last modified: March 15, 2023

Presented by The Joe Martin Foundation for Exceptional Craftsmanship