Chiang Mai Journal of Science

     This paper has investigated the effects of an alternative hybrid hydrogen-gasohol E20 fueled spark ignition engine on engine performance and exhaust pollutants. A hydrogen mixture with gasohol E20 was performed in an external mixture formation by installing a hydrogen fuel injection kit into the intake manifold area which is responsible for injecting hydrogen fuel into the inside of the engine’s cylinder. The hydrogen energy fraction in the intake was gradually increased from 3% to 9% ignition degree in the range of 20°, 25°, 30° and 35° before top dead center were controlled by using the electronic control unit to study the optimal condition for a four-stroke single-cylinder engine. In the steady-state test condition with half-open throttle under the variable load engine at 28%, 42%, 56%, and 70% of maximum engine torque, the engine can be available satisfactorily for an average relative air-fuel ratio (λ) value of 1.2 for hybrid hydrogen-gasohol E20 fuel. The results indicated that when the increase of hydrogen volume fraction. Postponing the spark timing was closer to top dead center (TDC) at 25° BTDC, the brake power and thermal engine efficiency increases. It is also noted that postponing the spark timing also caused NO_x, HC and CO emissions to decrease. NO_x emissions increased as the hydrogen volume fraction increased, whereas HC and CO emissions decreased.