In the present paper the steam cycle proposed by Spazzafumo has been again taken into consideration and the effect of the flow variation on the cycle performances has been investigated. The isothermal expansion with increasing flow causes a decrease in cycle efficiency due to the: greater condenser losses and, at high superheated temperatures, to the impossibility of full recovering of the available heat at the end of the expansion. However, using part of this heat for preheating the required hydrogen and oxygen, yields a significant increase in efficiency.