Thermal-lag engines with single pistons typically exhibit low thermodynamic performance, leading to a demand for enhanced configurations. In this study, a V-shaped thermal-lag engine, which combines two simple thermal-lag engines, has been proposed. The engine performance of the V-shaped thermal-lag engine (VTLE) has been numerically predicted using a mathematical model based on conservation equations for mass and energy, the ideal-gas equation of state, the constant-mass equation, and the pressure-loss equation. The VTLE excels in power generation, delivering 2.87 W—more than double the 1.41 W output of the single TLE—thanks to its innovative V-shaped configuration. A parametric study on engine performance revealed that the engine can achieve a maximum power of 5.34 W at a thermal resistance of 1.26 K/W and a maximum efficiency of 3.43% at 1.52 K/W.