Internal-combustion engine

In a liquid cooled reciprocating internal combustion engine having at least one cylinder with a piston and a cylinder head (4) the combination comprising:

• a supporting platform mounting said engine,
• a cooling-liquid system including a cooling liquid of predetermined composition wherein the boiling point of the cooling liquid lies between 110.degree. C. and 130.degree. C.,
• a cooling fan (2) having a diffuser (3) operable to deliver cooling air at an elevated pressure,
• a liquid/air heat exchanger (1) mounted on said platform separately of said engine,
• a scoop (8) and a flexible elastic boot (9) interconnected between said cooling air fan (2) and said liquid/air heat exchanger (1) whereby the latter is supplied cooling air at an elevated pressure from said cooling fan (2);
• and
• an exhaust duct (5) in said cylinder head (4) having a substantial portion which projects outwardly so it is thermally isolated from nearby regions of the cylinder head.