Much effort has been made to develop ceramic engine. Power turbines are usually used to recover excessive exhaust energy. The unsatisfactory problems are their high initial cost, complex structure and poor acceleration response. In the new system suggested here, the excessive exhaust energy is transferred to crank work through the pre-expanding process by higher pressurized intaked air during the intake stroke, thus the cycle temperature is lowered. Both thermodynamic analysis and performance simulation of this system were made, results showed that the fuel consumption of the new system could achieve the lever of power turbine's. A test bed of turbocharged engine was used to study the performance of the new system.Because of its simple structure, high acceleration response and low cycle temperature which leads to low NOx emission, this system is thought to be a competitive candidate for adiabatic engine sets.