Cirrus engine

1/4 scale model built by Merritt Zimmerman, circa 1989, L=19″, W=8″, H=10″

The 1/4 scale Cirrus 4-cylinder model is one of six made by Merritt Zimmerman. It operates on gasoline with oil mixed in for lubrication. Zimmerman also made 75 1/6-scale-model Cirrus 4-cylinder engines. (One 1/6-scale model also is on display.)

Zimmerman began building miniature engines in the 1940s.  He designed and produced his own castings and also did his own machining. At 83, in less than six weeks, Zimmerman designed, built and tested a 1/4-scale model of the 5-cylinder Kinner radial engine. His engine and drawings were published in 1993 in construction articles in Strictly IC magazine (

The in-line engine has cylinders in a straight row, or in two rows side-by-side.  The full-size Cirrus 4-cylinder was commonly used in the Avro Baby (designed in 1918) and the de Havilland D.H. 60 Moth (1930-1936).

Exhibit added: January 23, 2013 - Last modified: June 30, 2022

Presented by The Joe Martin Foundation for Exceptional Craftsmanship