This company made a couple of these small engines to be used on light aircraft.

-The Valmet 2H-157 is a two-stroke engine giving 10 hp, running on a 4% fuel-oil mixture.

“Valmet SM-160”

-The Valmet SM-160 is a two-stroke engine with 157 cc, similar to the 2H-157, with a compression ratio of 9.6 to 1 and giving 10 hp at 6,500 rpm.

“Cri-Cri Aircraft”

-Lacking the cooling cowling that these engines have to force air through the cylinder fins, their final appearance is as seen in the photo.

-The Cri-Cri is a successful aircraft, tremendously small, as we can see in the below photo, where the crew member seems wedged inside it. Its builder is Michel Colombon, and the aircraft model is the MC-12.

“Cri-Cri, MC-12”

-Resoundingly successful, this aircraft is still inferior to the “Pou-du-Ciel” aircraft. But it's much newer.

-It has two engines arranged on two elongated front struts, which help sweep the cylinder and direct gases away from the cockpit.