Development of a New 12 Valve 4 Cylinder Engine

The 1.5 1 GA15 engine is a new inline 4 cylinder engine. The GA15 fully meets the major development objectives of sufficient torque at low and middle engine speeds, high power output, good fuel economy and quiet engine operation.

Its structure features a compact combustion chamber with a small bore and long stroke, aerodynamic intake ports, a stiff engine cylinder block with a deep skirt and bearing beam, a newly designed silentrunning chaine, and pistons with full floating pins. High quality was achieved by adopting the latest methods in its development: vibration analysis of the assembled engine and transmission, FEM model, rigidity analysis of the cylinder block and head, and analysis of air flow in the intake port and movement of the timing chain.