CONSTRUCTION
The cylinder head structure has been simplified by separating the camshaft housing (cam journal portion) from the cylinder head sub-assembly.
The cylinder head sub-assembly, which is made of aluminum, contains a pentroof-type combustion chamber. The spark plug is located in the center of the combustion chamber in order to improve the engine's anti-knocking performance.
The angle of the intake and exhaust valves is narrowed and set at 29° to permit a compact cylinder head.
Spark plugs with an M12 thread size are used in order to increase the diameter of the intake and exhaust valves. As a result, improved intake and exhaust efficiency has been achieved.
A taper squish combustion chamber is used to improve anti-knocking performance and intake efficiency. In addition, engine performance and fuel economy have been improved.
Long nozzle type fuel injectors are installed in the cylinder head to reduce the distance from the fuel injector to the intake valve, thus preventing the fuel from adhering to the intake port walls and reducing HC exhaust emissions.
| *1 | Intake Valve | *2 | Spark Plug Hole |
| *3 | Exhaust Valve | *4 | Camshaft Housing |
| *5 | Taper Squish | - | - |
| *a | View from Bottom Side | *b | Intake Side |
| *c | Exhaust Side | *d | A - A Cross Section |
A siamese type intake port is used to reduce the overall surface area of the intake port walls. This prevents the fuel from adhering to the intake port walls, thus reducing HC exhaust emissions.
| *a | Siamese Type | *b | Independent Type |