The Poinsard 25 hp or Mengin Type B is a small, two-cylinder, air-cooled, horizontally opposed aircraft engine built in France.
it was manufactured by Établissements Pierre Mengin from a design by René Poinsard.
The first two engines built by Mengin were designed by René Poinsard and are often referred to by his name The Mengin B or Poinsard 25 hp was the first and smaller of the two.
Aimed at very small, single seat sport aircraft it went into production from about 1933.
[1] Data from Horizontally Opposed Aero Engines[1] unless other source indicated Data from Horizontally Opposed Aero Engines[1]