Hot air engine comprising at least one compression cylinder connected to a delivery manifold and an inlet manifold for the input and output from the cylinder of an operating fluid, at least one expansion cylinder connected to an expansion manifold and to an exhaust manifold for the input and output from the cylinder of an operating fluid, a transmission system of the movement of the expansion and compression cylinder pistons to a system for transforming the movement into electric power, being each cylinder (1, 2) connected with each manifold through a valve, so as to allow or prevent the passage of the operating fluid from the cylinder (1, 2) to the manifold and vice versa, wherein each valve has a valve seat and a closing element, which closing element is mounted rotatably with respect to said valve seat, so that the closing condition of the valve corresponds to an overlapping condition of the said closing element with respect to said valve seat, while the opening condition of said valve corresponds to a non-overlapping or partially overlapping condition of said closing element with respect to said valve seat, being the said closing element mounted in a translatable manner with respect to said valve seat in the direction of the manifold and the cylinder, so that a translation of the said closing element allows the passage of the operating fluid even in the overlapping condition of the closing element with the said valve seat, the said valve seat having a first opening facing the manifold and a second opening facing the cylinder, the said first and second opening being surrounded by a first and a second abutment surface, respectively, the said closing element consisting of a plate-like element, so that during translation the said plate-like element passes from a maximum approach condition to the manifold, wherein the surfaces of the plate-like element are in abutment with the said first abutment surface, to a maximum approach condition to the cylinder wherein the surfaces of the said plate-like element are in abutment with the said second abutment surface. at least one compression cylinder connected to a delivery manifold and an inlet manifold for the input and output from the cylinder of an operating fluid, at least one expansion cylinder connected to an expansion manifold and to an exhaust manifold for the input and output from the cylinder of an operating fluid, a transmission system of the movement of the expansion and compression cylinder pistons to a system for transforming the movement into electric power, being each cylinder (1, 2) connected with each manifold through a valve, so as to allow or prevent the passage of the operating fluid from the cylinder (1, 2) to the manifold and vice versa, wherein each valve has a valve seat and a closing element, which closing element is mounted rotatably with respect to said valve seat, so that the closing condition of the valve corresponds to an overlapping condition of the said closing element with respect to said valve seat, while the opening condition of said valve corresponds to a non-overlapping or partially overlapping condition of said closing element with respect to said valve seat, being the said closing element mounted in a translatable manner with respect to said valve seat in the direction of the manifold and the cylinder, so that a translation of the said closing element allows the passage of the operating fluid even in the overlapping condition of the closing element with the said valve seat, the said valve seat having a first opening facing the manifold and a second opening facing the cylinder, the said first and second opening being surrounded by a first and a second abutment surface, respectively, the said closing element consisting of a plate-like element, so that during translation the said plate-like element passes from a maximum approach condition to the manifold, wherein the surfaces of the plate-like element are in abutment with the said first abutment surface, to a maximum approach condition to the cylinder wherein the surfaces of the said plate-like element are in abutment with the said second abutment surface.