On the basis of the wall-guided

spray-guided and air-guided technologies related with gasoline direct injection

the scheme of complex-guided stratified charge combustion system for direct-injection spark-ignited(DISI)methanol engine was developed. The test engine was retrofitted from a 4-cylinder diesel engine. The major parameters were optimized

such as the location of the wall guider

the protruding distance of the spark plug

swirl ratio

injection and ignition timing

nozzle type

and needle valve open pressure. The DISI methanol engine can work with the excessive air/fuel ratio as high as 2.23 at a speed of 1 500 r/min. The engine torque is 135 N·m(65.5% of diesel engine torque)and the thermal efficiency reaches 29.7%. The test results indicate that the developed DISI methanol engine can realize a good match for the stratified charge combustion.