(See Berthaud).

In 1909, they made a 2-stroke engine based on the same principle as the Trent and Bévier engines.

“Prini et Berthaud”

-The cylinders and pistons had double bore: in one part the mixture was compressed so that it entered the other active part.

“Prini et Berthaud”

-The active bore is 100 mm by 110 stroke, giving 50 CV at 1,464 rpm and it weighed 92 Kg.

From Appendix 6: Below we show a better view of this atypical four-cylinder engine. Two cylinders are different from the other two, as we can see here.

-With the two-stroke cycle, it gave 50 hp at 1,400 rpm. The end pistons have double pistons with two different areas so that the lower one can sweep the upper one.

“Prini et Berthaud”