External combustion engine which comprises a first cylinder and a second cylinder, in which a first piston and a second piston are able to slide respectively. The first and second cylinder are fluidically connected with respect to each other for the passage of a heat-carrying fluid suitable to determine the cyclical movement of the first piston and the second piston. The external combustion engine also comprises a drive shaft rotating around an axis of rotation, and with which crank means are solidly associated, provided with at least a first pin and a second pin having pivoting axes parallel to each other, and also disposed distanced radially from the axis of rotation. The external combustion engine also comprises first and second kinematic connection means suitable to connect respectively the first pin and the second pin to the first piston and respectively to the second piston. The first pin and the second pin are disposed with the respective pivoting axes angularly offset so as to be angled by a desired angular amplitude equal to a first acute angle with respect to the axis of rotation.